Document:

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                                                                   EXHIBIT 10.5

                            OBJECTSWITCH CORPORATION

                          2000 KEY EMPLOYEE STOCK PLAN

                          ADOPTED ON DECEMBER 16, 1999

                            AS AMENDED AND RESTATED

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                                                                                              Page No.
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SECTION 1.  ESTABLISHMENT AND PURPOSE.......................................................       1

SECTION 2.  ADMINISTRATION..................................................................       1

   (a)  Committees of the Board of Directors................................................       1
   (b)  Authority of the Board of Directors.................................................       1

SECTION 3.  ELIGIBILITY.....................................................................       1

   (a)  General Rule........................................................................       1
   (b)  Ten-Percent Shareholders............................................................       1

SECTION 4.  STOCK SUBJECT TO PLAN...........................................................       1

   (a)  Basic Limitation....................................................................       2
   (b)  Additional Shares...................................................................       2

SECTION 5.  TERMS AND CONDITIONS OF AWARDS OR SALES.........................................       2

   (a)  Stock Purchase Agreement............................................................       2
   (b)  Duration of Offers and Nontransferability of Rights.................................       2
   (c)  Purchase Price......................................................................       2
   (d)  Withholding Taxes...................................................................       2
   (e)  Restrictions on Transfer of Shares and Minimum Vesting..............................       3
   (f)  Accelerated Vesting.................................................................       3

SECTION 6.  TERMS AND CONDITIONS OF OPTIONS.................................................       3

   (a)  Stock Option Agreement..............................................................       3
   (b)  Number of Shares....................................................................       3
   (c)  Exercise Price......................................................................       3
   (d)  Withholding Taxes...................................................................       3
   (e)  Exercisability......................................................................       4
   (f)  Accelerated Exercisability..........................................................       4
   (g)  Basic Term..........................................................................       4
   (h)  Nontransferability..................................................................       4
   (i)  Termination of Service (Except by Death)............................................       4
   (j)  Leaves of Absence...................................................................       5
   (k)  Death of Optionee...................................................................       5
   (l)  No Rights as a Shareholder..........................................................       5
   (m)  Modification, Extension and Assumption of Options...................................       5
   (n)  Restrictions on Transfer of Shares and Minimum Vesting..............................       5
   (o)  Accelerated Vesting.................................................................       6
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SECTION 7.  PAYMENT FOR SHARES..............................................................       6

   (a)  General Rule........................................................................       6
   (b)  Surrender of Stock..................................................................       6
   (c)  Services Rendered...................................................................       6
   (d)  Promissory Note.....................................................................       7
   (e)  Exercise/Sale.......................................................................       7
   (f)  Exercise/Pledge.....................................................................       7

SECTION 8.  ADJUSTMENT OF SHARES............................................................       7

   (a)  General.............................................................................       7
   (b)  Mergers and Consolidations..........................................................       7
   (c)  Reservation of Rights...............................................................       8

SECTION 9.  SECURITIES LAW REQUIREMENTS.....................................................       8

   (a)  General.............................................................................       8
   (b)  Financial Reports...................................................................       8

SECTION 10.  NO RETENTION RIGHTS............................................................       8

SECTION 11.  DURATION AND AMENDMENTS........................................................       8

   (a)  Term of the Plan....................................................................       8
   (b)  Right to Amend or Terminate the Plan................................................       9
   (c)  Effect of Amendment or Termination..................................................       9

SECTION 12.  DEFINITIONS....................................................................       9
</TABLE>

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              OBJECTSWITCH CORPORATION 2000 KEY EMPLOYEE STOCK PLAN

SECTION 1 ESTABLISHMENT AND PURPOSE.

             The purpose of the Plan is to offer selected individuals an
opportunity to acquire a proprietary interest in the success of the Company, or
to increase such interest, by purchasing Shares of the Company's Stock. The Plan
provides both for the direct award or sale of Shares and for the grant of
Options to purchase Shares. Options granted under the Plan may include
Nonstatutory Options as well as ISOs intended to qualify under Section 422 of
the Code.

             Capitalized terms are defined in Section 12.

SECTION 2 ADMINISTRATION.

             (a) COMMITTEES OF THE BOARD OF DIRECTORS. The Plan may be
administered by one or more Committees. Each Committee shall consist of one or
more members of the Board of Directors who have been appointed by the Board of
Directors. Each Committee shall have such authority and be responsible for such
functions as the Board of Directors has assigned to it. If no Committee has been
appointed, the entire Board of Directors shall administer the Plan. Any
reference to the Board of Directors in the Plan shall be construed as a
reference to the Committee (if any) to whom the Board of Directors has assigned
a particular function.

             (b) AUTHORITY OF THE BOARD OF DIRECTORS. Subject to the provisions
of the Plan, the Board of Directors shall have full authority and discretion to
take any actions it deems necessary or advisable for the administration of the
Plan. All decisions, interpretations and other actions of the Board of Directors
shall be final and binding on all Purchasers, all Optionees and all persons
deriving their rights from a Purchaser or Optionee.

SECTION 3 ELIGIBILITY.

             (a) GENERAL RULE. Only Employees, Outside Directors and Consultants
shall be eligible for the grant of Options or the direct award or sale of
Shares. Only Employees shall be eligible for the grant of ISOs.

             (b) TEN-PERCENT SHAREHOLDERS. An individual who owns more than 10%
of the total combined voting power of all classes of outstanding stock of the
Company, its Parent or any of its Subsidiaries shall not be eligible for
designation as an Optionee or Purchaser unless (i) the Exercise Price is at
least 110% of the Fair Market Value of a Share on the date of grant, (ii) the
Purchase Price (if any) is at least 100% of the Fair Market Value of a Share and
(iii) in the case of an ISO, such ISO by its terms is not exercisable after the
expiration of five years from the date of grant. For purposes of this Subsection
(b), in determining stock ownership, the attribution rules of Section 424(d) of
the Code shall be applied.

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SECTION 4 STOCK SUBJECT TO PLAN.

             (a) BASIC LIMITATION. Shares offered under the Plan may be
authorized but unissued Shares or treasury Shares. The aggregate number of
Shares that may be issued under the Plan (upon exercise of Options or other
rights to acquire Shares) shall not exceed 1,345,000 Shares, subject to
adjustment pursuant to Section 8. The number of Shares that are subject to
Options or other rights outstanding at any time under the Plan shall not exceed
the number of Shares that then remain available for issuance under the Plan. The
Company, during the term of the Plan, shall at all times reserve and keep
available sufficient Shares to satisfy the requirements of the Plan.

             (b) ADDITIONAL SHARES. In the event that any outstanding Option or
other right for any reason expires or is canceled or otherwise terminated, the
Shares allocable to the unexercised portion of such Option or other right shall
again be available for the purposes of the Plan. In the event that Shares issued
under the Plan are reacquired by the Company pursuant to any forfeiture
provision, right of repurchase or right of first refusal, such Shares shall
again be available for the purposes of the Plan, except that the aggregate
number of Shares which may be issued upon the exercise of ISOs shall in no event
exceed 1,345,000 Shares (subject to adjustment pursuant to Section 8).

SECTION 5 TERMS AND CONDITIONS OF AWARDS OR SALES.

             (a) STOCK PURCHASE AGREEMENT. Each award or sale of Shares under
the Plan (other than upon exercise of an Option) shall be evidenced by a Stock
Purchase Agreement between the Purchaser and the Company. Such award or sale
shall be subject to all applicable terms and conditions of the Plan and may be
subject to any other terms and conditions which are not inconsistent with the
Plan and which the Board of Directors deems appropriate for inclusion in a Stock
Purchase Agreement. The provisions of the various Stock Purchase Agreements
entered into under the Plan need not be identical.

             (b) DURATION OF OFFERS AND NONTRANSFERABILITY OF RIGHTS. Any right
to acquire Shares under the Plan (other than an Option) shall automatically
expire if not exercised by the Purchaser within 30 days after the grant of such
right was communicated to the Purchaser by the Company. Such right shall not be
transferable and shall be exercisable only by the Purchaser to whom such right
was granted.

             (c) PURCHASE PRICE. The Purchase Price of Shares to be offered
under the Plan shall not be less than 85% of the Fair Market Value of such
Shares, and a higher percentage may be required by Section 3(b). Subject to the
preceding sentence, the Purchase Price shall be determined by the Board of
Directors at its sole discretion. The Purchase Price shall be payable in a form
described in Section 7.

             (d) WITHHOLDING TAXES. As a condition to the purchase of Shares,
the Purchaser shall make such arrangements as the Board of Directors may require
for the satisfaction of any federal, state, local or foreign withholding tax
obligations that may arise in connection with such purchase.

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             (e) RESTRICTIONS ON TRANSFER OF SHARES AND MINIMUM VESTING. Any
Shares awarded or sold under the Plan shall be subject to such special
forfeiture conditions, rights of repurchase, rights of first refusal and other
transfer restrictions as the Board of Directors may determine. Such restrictions
shall be set forth in the applicable Stock Purchase Agreement and shall apply in
addition to any restrictions that may apply to holders of Shares generally. In
the case of a Purchaser who is not an officer of the Company, an Outside
Director or a Consultant, any right to repurchase the Purchaser's Shares at the
original Purchase Price (if any) upon termination of the Purchaser's Service
shall lapse at least as rapidly as 20% per year over the five-year period
commencing on the date of the award or sale of the Shares. Any such right may be
exercised only within 90 days after the termination of the Purchaser's Service
for cash or for cancellation of indebtedness incurred in purchasing the Shares.

             (f) ACCELERATED VESTING. Unless the applicable Stock Purchase
Agreement provides otherwise, any right to repurchase a Purchaser's Shares at
the original Purchase Price (if any) upon termination of the Purchaser's Service
shall lapse and all of such Shares shall become vested if (i) the Company is
subject to a Change in Control before the Purchaser's Service terminates and
(ii) the repurchase right is not assigned to the entity that employs the
Purchaser immediately after the Change in Control or to its parent or
subsidiary.

SECTION 6 TERMS AND CONDITIONS OF OPTIONS.

             (a) STOCK OPTION AGREEMENT. Each grant of an Option under the Plan
shall be evidenced by a Stock Option Agreement between the Optionee and the
Company. Such Option shall be subject to all applicable terms and conditions of
the Plan and may be subject to any other terms and conditions which are not
inconsistent with the Plan and which the Board of Directors deems appropriate
for inclusion in a Stock Option Agreement. The provisions of the various Stock
Option Agreements entered into under the Plan need not be identical.

             (b) NUMBER OF SHARES. Each Stock Option Agreement shall specify the
number of Shares that are subject to the Option and shall provide for the
adjustment of such number in accordance with Section 8. The Stock Option
Agreement shall also specify whether the Option is an ISO or a Nonstatutory
Option.

             (c) EXERCISE PRICE. Each Stock Option Agreement shall specify the
Exercise Price. The Exercise Price of an ISO shall not be less than 100% of the
Fair Market Value of a Share on the date of grant, and a higher percentage may
be required by Section 3(b). The Exercise Price of a Nonstatutory Option shall
not be less than 85% of the Fair Market Value of a Share on the date of grant,
and a higher percentage may be required by Section 3(b). Subject to the
preceding two sentences, the Exercise Price under any Option shall be determined
by the Board of Directors at its sole discretion. The Exercise Price shall be
payable in a form described in Section 7.

             (d) WITHHOLDING TAXES. As a condition to the exercise of an Option,
the Optionee shall make such arrangements as the Board of Directors may require
for the satisfaction of any federal, state, local or foreign withholding tax
obligations that may arise in connection with such exercise. The Optionee shall
also make such arrangements as the Board of Directors

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may require for the satisfaction of any federal, state, local or foreign
withholding tax obligations that may arise in connection with the disposition of
Shares acquired by exercising an Option.

             (e) EXERCISABILITY. Each Stock Option Agreement shall specify the
date when all or any installment of the Option is to become exercisable. In the
case of an Optionee who is not an officer of the Company, an Outside Director or
a Consultant, an Option shall become exercisable at least as rapidly as 20% per
year over the five-year period commencing on the date of grant. Subject to the
preceding sentence, the exercisability provisions of any Stock Option Agreement
shall be determined by the Board of Directors at its sole discretion.

             (f) ACCELERATED EXERCISABILITY. Unless the applicable Stock Option
Agreement provides otherwise, all of an Optionee's Options shall become
exercisable in full if (i) the Company is subject to a Change in Control before
the Optionee's Service terminates, (ii) such Options do not remain outstanding,
(iii) such Options are not assumed by the surviving corporation or its parent
and (iv) the surviving corporation or its parent does not substitute options
with substantially the same terms for such Options.

             (g) BASIC TERM. The Stock Option Agreement shall specify the term
of the Option. The term shall not exceed 10 years from the date of grant, and a
shorter term may be required by Section 3(b). Subject to the preceding sentence,
the Board of Directors at its sole discretion shall determine when an Option is
to expire.

             (h) NONTRANSFERABILITY. No Option shall be transferable by the
Optionee other than by beneficiary designation, will or the laws of descent and
distribution. An Option may be exercised during the lifetime of the Optionee
only by the Optionee or by the Optionee's guardian or legal representative. No
Option or interest therein may be transferred, assigned, pledged or hypothecated
by the Optionee during the Optionee's lifetime, whether by operation of law or
otherwise, or be made subject to execution, attachment or similar process.

             (i) TERMINATION OF SERVICE (EXCEPT BY DEATH). If an Optionee's
Service terminates for any reason other than the Optionee's death, then the
Optionee's Options shall expire on the earliest of the following occasions:

             (i) The expiration date determined pursuant to Subsection (g)
        above;

             (ii) The date three months after the termination of the Optionee's
        Service for any reason other than Disability, or such later date as the
        Board of Directors may determine; or

             (iii) The date six months after the termination of the Optionee's
        Service by reason of Disability, or such later date as the Board of
        Directors may determine.

The Optionee may exercise all or part of the Optionee's Options at any time
before the expiration of such Options under the preceding sentence, but only to
the extent that such Options had become exercisable before the Optionee's
Service terminated (or became exercisable as a result of the termination) and
the underlying Shares had vested before the Optionee's Service terminated (or
vested as a result of the termination). The balance of such Options shall lapse

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when the Optionee's Service terminates. In the event that the Optionee dies
after the termination of the Optionee's Service but before the expiration of the
Optionee's Options, all or part of such Options may be exercised (prior to
expiration) by the executors or administrators of the Optionee's estate or by
any person who has acquired such Options directly from the Optionee by
beneficiary designation, bequest or inheritance, but only to the extent that
such Options had become exercisable before the Optionee's Service terminated (or
became exercisable as a result of the termination) and the underlying Shares had
vested before the Optionee's Service terminated (or vested as a result of the
termination).

             (j) LEAVES OF ABSENCE. For purposes of Subsection (i) above,
Service shall be deemed to continue while the Optionee is on a bona fide leave
of absence, if such leave was approved by the Company in writing and if
continued crediting of Service for this purpose is expressly required by the
terms of such leave or by applicable law (as determined by the Company).

             (k) DEATH OF OPTIONEE. If an Optionee dies while the Optionee is in
Service, then the Optionee's Options shall expire on the earlier of the
following dates:

             (i) The expiration date determined pursuant to Subsection (g)
        above; or

             (ii) The date 12 months after the Optionee's death.

All or part of the Optionee's Options may be exercised at any time before the
expiration of such Options under the preceding sentence by the executors or
administrators of the Optionee's estate or by any person who has acquired such
Options directly from the Optionee by beneficiary designation, bequest or
inheritance, but only to the extent that such Options had become exercisable
before the Optionee's death or became exercisable as a result of the death. The
balance of such Options shall lapse when the Optionee dies.

             (l) NO RIGHTS AS A SHAREHOLDER. An Optionee, or a transferee of an
Optionee, shall have no rights as a shareholder with respect to any Shares
covered by the Optionee's Option until such person becomes entitled to receive
such Shares by filing a notice of exercise and paying the Exercise Price
pursuant to the terms of such Option.

             (m) MODIFICATION, EXTENSION AND ASSUMPTION OF OPTIONS. Within the
limitations of the Plan, the Board of Directors may modify, extend or assume
outstanding Options or may accept the cancellation of outstanding Options
(whether granted by the Company or another issuer) in return for the grant of
new Options for the same or a different number of Shares and at the same or a
different Exercise Price. The foregoing notwithstanding, no modification of an
Option shall, without the consent of the Optionee, impair the Optionee's rights
or increase the Optionee's obligations under such Option.

             (n) RESTRICTIONS ON TRANSFER OF SHARES AND MINIMUM VESTING. Any
Shares issued upon exercise of an Option shall be subject to such special
forfeiture conditions, rights of repurchase, rights of first refusal and other
transfer restrictions as the Board of Directors may determine. Such restrictions
shall be set forth in the applicable Stock Option Agreement and

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shall apply in addition to any restrictions that may apply to holders of Shares
generally. In the case of an Optionee who is not an officer of the Company, an
Outside Director or a Consultant:

             (i) Any right to repurchase the Optionee's Shares at the original
        Exercise Price upon termination of the Optionee's Service shall lapse at
        least as rapidly as 20% per year over the five-year period commencing on
        the date of the option grant;

             (ii) Any such right may be exercised only for cash or for
        cancellation of indebtedness incurred in purchasing the Shares; and

             (iii) Any such right may be exercised only within 90 days after the
        later of (A) the termination of the Optionee's Service or (B) the date
        of the option exercise.

             (o) ACCELERATED VESTING. Unless the applicable Stock Option
Agreement provides otherwise, the following provisions shall govern any options
granted pursuant to Section 6. Any right to repurchase an Optionee's Shares at
the original Exercise Price upon termination of the Optionee's Service shall
lapse and all of such Shares shall become vested if (i) the Company is subject
to a Change in Control before the Optionee's Service terminates and (ii) the
repurchase right is not assigned to the entity that employs the Optionee
immediately after the Change in Control or to its parent or subsidiary.
Furthermore, if (i) the Company is subject to a Change in Control before an
Optionee's Service terminates, (ii) the repurchase right is assigned to the
acquiring entity or its parent or subsidiary and (iii) there is an Involuntary
Termination of an Optionee's Service within twelve (12) months following the
Change in Control, any right to repurchase the Optionee's Shares at the original
Exercise Price upon termination of the Optionee's Service shall lapse and all of
such Shares shall become vested.

SECTION 7 PAYMENT FOR SHARES.

             (a) GENERAL RULE. The entire Purchase Price or Exercise Price of
Shares issued under the Plan shall be payable in cash or cash equivalents at the
time when such Shares are purchased, except as otherwise provided in this
Section 7.

             (b) SURRENDER OF STOCK. To the extent that a Stock Option Agreement
so provides, all or any part of the Exercise Price may be paid by surrendering,
or attesting to the ownership of, Shares that are already owned by the Optionee.
Such Shares shall be surrendered to the Company in good form for transfer and
shall be valued at their Fair Market Value on the date when the Option is
exercised. The Optionee shall not surrender, or attest to the ownership of,
Shares in payment of the Exercise Price if such action would cause the Company
to recognize compensation expense (or additional compensation expense) with
respect to the Option for financial reporting purposes.

             (c) SERVICES RENDERED. At the discretion of the Board of Directors,
Shares may be awarded under the Plan in consideration of services rendered to
the Company, a Parent or a Subsidiary prior to the award.

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             (d) PROMISSORY NOTE. To the extent that a Stock Option Agreement or
Stock Purchase Agreement so provides, all or a portion of the Exercise Price or
Purchase Price (as the case may be) of Shares issued under the Plan may be paid
with a full-recourse promissory note. However, the par value of the Shares, if
newly issued, shall be paid in cash or cash equivalents. The Shares shall be
pledged as security for payment of the principal amount of the promissory note
and interest thereon. The interest rate payable under the terms of the
promissory note shall not be less than the minimum rate (if any) required to
avoid the imputation of additional interest under the Code. Subject to the
foregoing, the Board of Directors (at its sole discretion) shall specify the
term, interest rate, amortization requirements (if any) and other provisions of
such note.

             (e) EXERCISE/SALE. To the extent that a Stock Option Agreement so
provides, and if Stock is publicly traded, payment may be made all or in part by
the delivery (on a form prescribed by the Company) of an irrevocable direction
to a securities broker approved by the Company to sell Shares and to deliver all
or part of the sales proceeds to the Company in payment of all or part of the
Exercise Price and any withholding taxes.

             (f) EXERCISE/PLEDGE. To the extent that a Stock Option Agreement so
provides, and if Stock is publicly traded, payment may be made all or in part by
the delivery (on a form prescribed by the Company) of an irrevocable direction
to pledge Shares to a securities broker or lender approved by the Company, as
security for a loan, and to deliver all or part of the loan proceeds to the
Company in payment of all or part of the Exercise Price and any withholding
taxes.

SECTION 8 ADJUSTMENT OF SHARES.

             (a) GENERAL. In the event of a subdivision of the outstanding
Stock, a declaration of a dividend payable in Shares, a declaration of an
extraordinary dividend payable in a form other than Shares in an amount that has
a material effect on the Fair Market Value of the Stock, a combination or
consolidation of the outstanding Stock into a lesser number of Shares, a
recapitalization, a spin-off, a reclassification or a similar occurrence, the
Board of Directors shall make appropriate adjustments in one or more of (i) the
number of Shares available for future grants under Section 4, (ii) the number of
Shares covered by each outstanding Option or (iii) the Exercise Price under each
outstanding Option.

             (b) MERGERS AND CONSOLIDATIONS. In the event that the Company is a
party to a merger or consolidation, outstanding Options shall be subject to the
agreement of merger or consolidation. Such agreement, without the Optionees'
consent, may provide for:

             (i) The continuation of such outstanding Options by the Company (if
        the Company is the surviving corporation);

             (ii) The assumption of the Plan and such outstanding Options by the
        surviving corporation or its parent; or

             (iii) The substitution by the surviving corporation or its parent
        of options with substantially the same terms for such outstanding
        Options.

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             (c) RESERVATION OF RIGHTS. Except as provided in this Section 8, an
Optionee or Purchaser shall have no rights by reason of (i) any subdivision or
consolidation of shares of stock of any class, (ii) the payment of any dividend
or (iii) any other increase or decrease in the number of shares of stock of any
class. Any issuance by the Company of shares of stock of any class, or
securities convertible into shares of stock of any class, shall not affect, and
no adjustment by reason thereof shall be made with respect to, the number or
Exercise Price of Shares subject to an Option. The grant of an Option pursuant
to the Plan shall not affect in any way the right or power of the Company to
make adjustments, reclassifications, reorganizations or changes of its capital
or business structure, to merge or consolidate or to dissolve, liquidate, sell
or transfer all or any part of its business or assets.

SECTION 9 SECURITIES LAW REQUIREMENTS.

             (a) GENERAL. Shares shall not be issued under the Plan unless the
issuance and delivery of such Shares comply with (or are exempt from) all
applicable requirements of law, including (without limitation) the Securities
Act of 1933, as amended, the rules and regulations promulgated thereunder, state
securities laws and regulations, and the regulations of any stock exchange or
other securities market on which the Company's securities may then be traded.

             (b) FINANCIAL REPORTS. The Company each year shall furnish to
Optionees, Purchasers and shareholders who have received Stock under the Plan
its balance sheet and income statement, unless such Optionees, Purchasers or
shareholders are key Employees whose duties with the Company assure them access
to equivalent information. Such balance sheet and income statement need not be
audited.

SECTION 10 NO RETENTION RIGHTS.

             Nothing in the Plan or in any right or Option granted under the
Plan shall confer upon the Purchaser or Optionee any right to continue in
Service for any period of specific duration or interfere with or otherwise
restrict in any way the rights of the Company (or any Parent or Subsidiary
employing or retaining the Purchaser or Optionee) or of the Purchaser or
Optionee, which rights are hereby expressly reserved by each, to terminate his
or her Service at any time and for any reason, with or without cause.

SECTION 11 DURATION AND AMENDMENTS.

             (a) TERM OF THE PLAN. The Plan, as set forth herein, shall become
effective on the date of its adoption by the Board of Directors, subject to the
approval of the Company's shareholders. In the event that the shareholders fail
to approve the Plan within 12 months after its adoption by the Board of
Directors, any grants of Options or sales or awards of Shares that have already
occurred shall be rescinded, and no additional grants, sales or awards shall be
made thereafter under the Plan. The Plan shall terminate automatically 10 years
after its adoption by the Board of Directors and may be terminated on any
earlier date pursuant to Subsection (b) below.

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             (b) RIGHT TO AMEND OR TERMINATE THE PLAN. The Board of Directors
may amend, suspend or terminate the Plan at any time and for any reason;
provided, however, that any amendment of the Plan which increases the number of
Shares available for issuance under the Plan (except as provided in Section 8),
or which materially changes the class of persons who are eligible for the grant
of ISOs, shall be subject to the approval of the Company's shareholders.
Shareholder approval shall not be required for any other amendment of the Plan.

             (c) EFFECT OF AMENDMENT OR TERMINATION. No Shares shall be issued
or sold under the Plan after the termination thereof, except upon exercise of an
Option granted prior to such termination. The termination of the Plan, or any
amendment thereof, shall not affect any Share previously issued or any Option
previously granted under the Plan.

SECTION 12 DEFINITIONS.

             (a) "BOARD OF DIRECTORS" shall mean the Board of Directors of the
Company, as constituted from time to time.

             (b) "CHANGE IN CONTROL" shall mean:

             (i) The consummation of a merger or consolidation of the Company
        with or into another entity or any other corporate reorganization, if
        persons who were not shareholders of the Company immediately prior to
        such merger, consolidation or other reorganization own immediately after
        such merger, consolidation or other reorganization 50% or more of the
        voting power of the outstanding securities of each of (A) the continuing
        or surviving entity and (B) any direct or indirect parent corporation of
        such continuing or surviving entity; or

             (ii) The sale, transfer or other disposition of all or
        substantially all of the Company's assets.

A transaction shall not constitute a Change in Control if its sole purpose is to
change the state of the Company's incorporation or to create a holding company
that will be owned in substantially the same proportions by the persons who held
the Company's securities immediately before such transaction.

             (c) "CODE" shall mean the Internal Revenue Code of 1986, as
amended.

             (d) "COMMITTEE" shall mean a committee of the Board of Directors,
as described in Section 2(a).

             (e) "COMPANY" shall mean ObjectSwitch Corporation, a California
corporation.

             (f) "CONSULTANT" shall mean a person who performs bona fide
services for the Company, a Parent or a Subsidiary as a consultant or advisor,
excluding Employees and Outside Directors.

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             (g) "DISABILITY" shall mean that the Optionee is unable to engage
in any substantial gainful activity by reason of any medically determinable
physical or mental impairment.

             (h) "EMPLOYEE" shall mean any individual who is a common-law
employee of the Company, a Parent or a Subsidiary.

             (i) "EXERCISE PRICE" shall mean the amount for which one Share may
be purchased upon exercise of an Option, as specified by the Board of Directors
in the applicable Stock Option Agreement.

             (j) "FAIR MARKET VALUE" shall mean the fair market value of a
Share, as determined by the Board of Directors in good faith. Such determination
shall be conclusive and binding on all persons.

             (k) "ISO" shall mean an employee incentive stock option described
in Section 422(b) of the Code.

             (l) "NONSTATUTORY OPTION" shall mean a stock option not described
in Sections 422(b) or 423(b) of the Code.

             (m) "OPTION" shall mean an ISO or Nonstatutory Option granted under
the Plan and entitling the holder to purchase Shares.

             (n) "OPTIONEE" shall mean an individual who holds an Option.

             (o) "OUTSIDE DIRECTOR" shall mean a member of the Board of
Directors who is not an Employee.

             (p) "PARENT" shall mean any corporation (other than the Company) in
an unbroken chain of corporations ending with the Company, if each of the
corporations other than the Company owns stock possessing 50% or more of the
total combined voting power of all classes of stock in one of the other
corporations in such chain. A corporation that attains the status of a Parent on
a date after the adoption of the Plan shall be considered a Parent commencing as
of such date.

             (q) "PLAN" shall mean this ObjectSwitch Corporation 2000 Key
Employee Plan.

             (r) "PURCHASE PRICE" shall mean the consideration for which one
Share may be acquired under the Plan (other than upon exercise of an Option), as
specified by the Board of Directors.

             (s) "PURCHASER" shall mean an individual to whom the Board of
Directors has offered the right to acquire Shares under the Plan (other than
upon exercise of an Option).

             (t) "SERVICE" shall mean service as an Employee, Outside Director
or Consultant.

                                       10
<PAGE>   14

             (u) "SHARE" shall mean one share of Stock, as adjusted in
accordance with Section 8 (if applicable).

             (v) "STOCK" shall mean the Common Stock of the Company, with a par
value of $0.001 per Share.

             (w) "STOCK OPTION AGREEMENT" shall mean the agreement between the
Company and an Optionee which contains the terms, conditions and restrictions
pertaining to the Optionee's Option.

             (x) "STOCK PURCHASE AGREEMENT" shall mean the agreement between the
Company and a Purchaser who acquires Shares under the Plan which contains the
terms, conditions and restrictions pertaining to the acquisition of such Shares.

             (y) "SUBSIDIARY" means any corporation (other than the Company) in
an unbroken chain of corporations beginning with the Company, if each of the
corporations other than the last corporation in the unbroken chain owns stock
possessing 50% or more of the total combined voting power of all classes of
stock in one of the other corporations in such chain. A corporation that attains
the status of a Subsidiary on a date after the adoption of the Plan shall be
considered a Subsidiary commencing as of such date.

                                       11

<PAGE>   15
                            OBJECTSWITCH CORPORATION
                          2000 KEY EMPLOYEE STOCK PLAN

                          NOTICE OF STOCK OPTION GRANT

               You have been granted the following option to purchase Common
Stock of ObjectSwitch Corporation (the "Company"):

<TABLE>
<S>                                                <C>
               Name of Optionee:                   <<Name>>

               Total Number of Shares Granted:     <<TotalShares>>

               Type of Option:                     <<ISO>> Incentive Stock Option

                                                   <<NSO>>  Nonstatutory Stock Option

               Exercise Price Per Share:           $<<PricePerShare>>

               Date of Grant:                      <<DateGrant>>

               Date Exercisable:                   This option may be exercised, in whole or
                                                   in part, for 100% of the Shares subject to
                                                   this option at any time after the Date of
                                                   Grant.

               Vesting Commencement Date:          <<VestComDate>>

               Vesting Schedule:                   The Right of Repurchase shall lapse with
                                                   respect to the first <<Percent>>% of the
                                                   Shares subject to this option when the
                                                   Optionee completes <<CliffPeriod>> months of
                                                   continuous Service after the Vesting
                                                   Commencement Date.  The Right of
                                                   Repurchase shall lapse with respect to an
                                                   additional <<Fraction>>% of the Shares
                                                   subject to this option when the Optionee
                                                   completes each month of continuous Service
                                                   thereafter.

               Expiration Date:                    <<ExpDate>>
</TABLE>

By your signature and the signature of the Company's representative below, you
and the Company agree that this option is granted under and governed by the
terms and conditions of the 2000 Key Employee Stock Plan and the Stock Option
Agreement, both of which are attached to and made a part of this document.

OPTIONEE:                                OBJECTSWITCH CORPORATION

                                         By:
----------------------------------              --------------------------------
                                         Title:
                                                --------------------------------

<PAGE>   16
THE OPTION GRANTED PURSUANT TO THIS AGREEMENT AND THE SHARES ISSUABLE UPON THE
EXERCISE THEREOF HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
AMENDED, AND MAY NOT BE SOLD, PLEDGED, OR OTHERWISE TRANSFERRED WITHOUT AN
EFFECTIVE REGISTRATION THEREOF UNDER SUCH ACT OR AN OPINION OF COUNSEL,
SATISFACTORY TO THE COMPANY AND ITS COUNSEL, THAT SUCH REGISTRATION IS NOT
REQUIRED.

             OBJECTSWITCH CORPORATION 2000 KEY EMPLOYEE STOCK PLAN:
                             STOCK OPTION AGREEMENT

SECTION 1. GRANT OF OPTION.

            (a) OPTION. On the terms and conditions set forth in the Notice of
Stock Option Grant and this Agreement, the Company grants to the Optionee on the
Date of Grant the option to purchase at the Exercise Price the number of Shares
set forth in the Notice of Stock Option Grant. The Exercise Price is agreed to
be at least 100% of the Fair Market Value per Share on the Date of Grant (110%
of Fair Market Value if Section 3(b) of the Plan applies). This option is
intended to be an ISO or a Nonstatutory Option, as provided in the Notice of
Stock Option Grant.

            (b) STOCK PLAN AND DEFINED TERMS. This option is granted pursuant to
the Plan, a copy of which the Optionee acknowledges having received. The
provisions of the Plan are incorporated into this Agreement by this reference.
Capitalized terms are defined in Section 14 of this Agreement.

SECTION 2. RIGHT TO EXERCISE.

            (a) EXERCISABILITY. Subject to Subsections (b) and (c) below and the
other conditions set forth in this Agreement, all or part of this option may be
exercised prior to its expiration at the time or times set forth in the Notice
of Stock Option Grant. Shares purchased by exercising this option may be subject
to the Right of Repurchase under Section 7.

            (b) $100,000 LIMITATION. If this option is designated as an ISO in
the Notice of Stock Option Grant, then the Optionee's right to exercise this
option shall be deferred to the extent (and only to the extent) that this option
otherwise would not be treated as an ISO by reason of the $100,000 annual
limitation under Section 422(d) of the Code, except that:

                  (i) The Optionee's right to exercise this option shall in any
      event become exercisable at least as rapidly as 20% per year over the
      five-year period commencing on the Date of Grant, unless the Optionee is
      an officer of the Company, an Outside Director or a Consultant; and

                  (ii) The Optionee's right to exercise this option shall no
      longer be deferred if (A) the Company is subject to a Change in Control
      before the

<PAGE>   17
      Optionee's Service terminates, (B) this option does not remain
      outstanding, (C) this option is not assumed by the surviving corporation
      or its parent and (D) the surviving corporation or its parent does not
      substitute an option with substantially the same terms for this option.

            (c) SHAREHOLDER APPROVAL. Any other provision of this Agreement
notwithstanding, no portion of this option shall be exercisable at any time
prior to the approval of the Plan by the Company's shareholders.

SECTION 3. NO TRANSFER OR ASSIGNMENT OF OPTION.

               Except as otherwise provided in this Agreement, this option and
the rights and privileges conferred hereby shall not be sold, pledged or
otherwise transferred (whether by operation of law or otherwise) and shall not
be subject to sale under execution, attachment, levy or similar process.

SECTION 4. EXERCISE PROCEDURES.

            (a) NOTICE OF EXERCISE. The Optionee or the Optionee's
representative may exercise this option by giving written notice to the Company
pursuant to Section 13(c). The notice shall specify the election to exercise
this option, the number of Shares for which it is being exercised and the form
of payment. The notice shall be signed by the person exercising this option. In
the event that this option is being exercised by the representative of the
Optionee, the notice shall be accompanied by proof (satisfactory to the Company)
of the representative's right to exercise this option. The Optionee or the
Optionee's representative shall deliver to the Company, at the time of giving
the notice, payment in a form permissible under Section 5 for the full amount of
the Purchase Price.

            (b) ISSUANCE OF SHARES. After receiving a proper notice of exercise,
the Company shall cause to be issued a certificate or certificates for the
Shares as to which this option has been exercised, registered in the name of the
person exercising this option (or in the names of such person and his or her
spouse as community property or as joint tenants with right of survivorship).
The Company shall cause such certificate or certificates to be deposited in
escrow or delivered to or upon the order of the person exercising this option.

            (c) WITHHOLDING TAXES. In the event that the Company determines that
it is required to withhold any tax as a result of the exercise of this option,
the Optionee, as a condition to the exercise of this option, shall make
arrangements satisfactory to the Company to enable it to satisfy all withholding
requirements. The Optionee shall also make arrangements satisfactory to the
Company to enable it to satisfy any withholding requirements that may arise in
connection with the vesting or disposition of Shares purchased by exercising
this option.

SECTION 5. PAYMENT FOR STOCK.

            (a) CASH. All or part of the Purchase Price may be paid in cash or
cash equivalents.

                                       2
<PAGE>   18
            (b) SURRENDER OF STOCK. All or any part of the Purchase Price may be
paid by surrendering, or attesting to the ownership of, Shares that are already
owned by the Optionee. Such Shares shall be surrendered to the Company in good
form for transfer and shall be valued at their Fair Market Value on the date
when this option is exercised. The Optionee shall not surrender, or attest to
the ownership of, Shares in payment of the Purchase Price if such action would
cause the Company to recognize compensation expense (or additional compensation
expense) with respect to this option for financial reporting purposes.

            (c) EXERCISE/SALE. If Stock is publicly traded, all or part of the
Purchase Price and any withholding taxes may be paid by the delivery (on a form
prescribed by the Company) of an irrevocable direction to a securities broker
approved by the Company to sell Shares and to deliver all or part of the sales
proceeds to the Company.

            (d) EXERCISE/PLEDGE. If Stock is publicly traded, all or part of the
Purchase Price and any withholding taxes may be paid by the delivery (on a form
prescribed by the Company) of an irrevocable direction to pledge Shares to a
securities broker or lender approved by the Company, as security for a loan, and
to deliver all or part of the loan proceeds to the Company.

            (e) PROMISSORY NOTE. All or part of the Purchase Price may be paid
with a full-recourse promissory note. However, the par value of the Shares, if
newly issued, shall be paid in cash or cash equivalents. The Shares shall be
pledged as security for payment of the principal amount of the promissory note
and interest thereon. The interest rate payable under the terms of the
promissory note shall not be less than the minimum rate (if any) required to
avoid the imputation of additional interest under the Code. Subject to the
foregoing, the Board of Directors (at its sole discretion) shall specify the
term, interest rate, amortization requirements (if any) and other provisions of
such note.

SECTION 6. TERM AND EXPIRATION.

            (a) BASIC TERM. This option shall in any event expire on the
expiration date set forth in the Notice of Stock Option Grant, which date is 10
years after the Date of Grant (five years after the Date of Grant if this option
is designated as an ISO in the Notice of Stock Option Grant and Section 3(b) of
the Plan applies).

            (b) TERMINATION OF SERVICE (EXCEPT BY DEATH). If the Optionee's
Service terminates for any reason other than death, then this option shall
expire on the earliest of the following occasions:

                  (i) The expiration date determined pursuant to Subsection (a)
      above;

                  (ii) The date three months after the termination of the
      Optionee's Service for any reason other than Disability; or

                   (iii) The date six months after the termination of the
      Optionee's Service by reason of Disability.

                                       3
<PAGE>   19
The Optionee may exercise all or part of this option at any time before its
expiration under the preceding sentence, but only to the extent that this option
had become exercisable for vested shares before the Optionee's Service
terminated. When the Optionee's Service terminates, this option shall expire
immediately with respect to the number of Shares for which this option is not
yet exercisable and with respect to any Restricted Shares. In the event that the
Optionee dies after termination of Service but before the expiration of this
option, all or part of this option may be exercised (prior to expiration) by the
executors or administrators of the Optionee's estate or by any person who has
acquired this option directly from the Optionee by beneficiary designation,
bequest or inheritance, but only to the extent that this option had become
exercisable before the Optionee's Service terminated.

            (c) DEATH OF THE OPTIONEE. If the Optionee dies while in Service,
then this option shall expire on the earlier of the following dates:

                   (i) The expiration date determined pursuant to Subsection (a)
        above; or

                   (ii) The date 12 months after the Optionee's death.

All or part of this option may be exercised at any time before its expiration
under the preceding sentence by the executors or administrators of the
Optionee's estate or by any person who has acquired this option directly from
the Optionee by beneficiary designation, bequest or inheritance, but only to the
extent that this option had become exercisable before the Optionee's death. When
the Optionee dies, this option shall expire immediately with respect to the
number of Shares for which this option is not yet exercisable and with respect
to any Restricted Shares.

            (d) LEAVES OF ABSENCE. For any purpose under this Agreement, Service
shall be deemed to continue while the Optionee is on a bona fide leave of
absence, if such leave was approved by the Company in writing and if continued
crediting of Service for such purpose is expressly required by the terms of such
leave or by applicable law (as determined by the Company).

            (e) NOTICE CONCERNING ISO TREATMENT. If this option is designated as
an ISO in the Notice of Stock Option Grant, it ceases to qualify for favorable
tax treatment as an ISO to the extent it is exercised (i) more than three months
after the date the Optionee ceases to be an Employee for any reason other than
death or permanent and total disability (as defined in Section 22(e)(3) of the
Code), (ii) more than 12 months after the date the Optionee ceases to be an
Employee by reason of such permanent and total disability or (iii) after the
Optionee has been on a leave of absence for more than 90 days, unless the
Optionee's reemployment rights are guaranteed by statute or by contract.

SECTION 7. RIGHT OF REPURCHASE.

            (a) SCOPE OF REPURCHASE RIGHT. Unless they have become vested in
accordance with the Notice of Stock Option Grant and Subsection (c) below, the
Shares acquired under this Agreement initially shall be Restricted Shares and
shall be subject to a right (but not an obligation) of repurchase by the
Company. The Optionee shall not transfer, assign, encumber or otherwise dispose
of any Restricted Shares, except as provided in the following sentence. The

                                       4
<PAGE>   20
Optionee may transfer Restricted Shares (i) by beneficiary designation, will or
intestate succession or (ii) to the Optionee's spouse, children or grandchildren
or to a trust established by the Optionee for the benefit of the Optionee or the
Optionee's spouse, children or grandchildren, provided in either case that the
Transferee agrees in writing on a form prescribed by the Company to be bound by
all provisions of this Agreement. If the Optionee transfers any Restricted
Shares, then this Section 7 shall apply to the Transferee to the same extent as
to the Optionee.

            (b) CONDITION PRECEDENT TO EXERCISE. The Right of Repurchase shall
be exercisable with respect to any Restricted Shares only during the 60-day
period next following the later of:

                   (i) The date when the Optionee's Service terminates for any
        reason, with or without cause, including (without limitation) death or
        disability; or

                   (ii) The date when such Restricted Shares were purchased by
        the Optionee, the executors or administrators of the Optionee's estate
        or any person who has acquired this option directly from the Optionee by
        bequest, inheritance or beneficiary designation.

            (c) LAPSE OF REPURCHASE RIGHT. The Right of Repurchase shall lapse
with respect to the Shares subject to this option in accordance with the vesting
schedule set forth in the Notice of Stock Option Grant. In addition, the Right
of Repurchase shall lapse and all of the remaining Restricted Shares shall
become vested if (i) the Company is subject to a Change in Control before the
Optionee's Service terminates and (ii) the Right of Repurchase is not assigned
to the acquiring entity or to its parent or subsidiary. Furthermore, if (i) the
Company is subject to a Change in Control before the Optionee's Service
terminates, (ii) the repurchase right is assigned to the acquiring entity or its
parent or subsidiary and (iii) there is an Involuntary Termination of Optionee's
Service within twelve (12) months following the Change in Control, the Right of
Repurchase shall automatically lapse and all of Optionee's Shares shall become
vested.

            (d) REPURCHASE COST. If the Company exercises the Right of
Repurchase, it shall pay the Optionee an amount equal to the Exercise Price for
each of the Restricted Shares being repurchased.

            (e) EXERCISE OF REPURCHASE RIGHT. The Right of Repurchase shall be
exercisable only by written notice delivered to the Optionee prior to the
expiration of the 60-day period specified in Subsection (b) above. The notice
shall set forth the date on which the repurchase is to be effected. Such date
shall not be more than 30 days after the date of the notice. The certificate(s)
representing the Restricted Shares to be repurchased shall, prior to the close
of business on the date specified for the repurchase, be delivered to the
Company properly endorsed for transfer. The Company shall, concurrently with the
receipt of such certificate(s), pay to the Optionee the purchase price
determined according to Subsection (d) above. Payment shall be made in cash or
cash equivalents or by canceling indebtedness to the Company incurred by the
Optionee in the purchase of the Restricted Shares. The Right of Repurchase shall

                                       5
<PAGE>   21
terminate with respect to any Restricted Shares for which it has not been timely
exercised pursuant to this Subsection (e).

            (f) ADDITIONAL SHARES OR SUBSTITUTED SECURITIES. In the event of the
declaration of a stock dividend, the declaration of an extraordinary dividend
payable in a form other than stock, a spin-off, a stock split, an adjustment in
conversion ratio, a recapitalization or a similar transaction affecting the
Company's outstanding securities without receipt of consideration, any new,
substituted or additional securities or other property (including money paid
other than as an ordinary cash dividend) which are by reason of such transaction
distributed with respect to any Restricted Shares or into which such Restricted
Shares thereby become convertible shall immediately be subject to the Right of
Repurchase. Appropriate adjustments to reflect the distribution of such
securities or property shall be made to the number and/or class of the
Restricted Shares. Appropriate adjustments shall also, after each such
transaction, be made to the price per share to be paid upon the exercise of the
Right of Repurchase in order to reflect any change in the Company's outstanding
securities effected without receipt of consideration therefor; provided,
however, that the aggregate purchase price payable for the Restricted Shares
shall remain the same.

            (g) TERMINATION OF RIGHTS AS SHAREHOLDER. If the Company makes
available, at the time and place and in the amount and form provided in this
Agreement, the consideration for the Restricted Shares to be repurchased in
accordance with this Section 7, then after such time the person from whom such
Restricted Shares are to be repurchased shall no longer have any rights as a
holder of such Restricted Shares (other than the right to receive payment of
such consideration in accordance with this Agreement). Such Restricted Shares
shall be deemed to have been repurchased in accordance with the applicable
provisions hereof, whether or not the certificate(s) therefor have been
delivered as required by this Agreement.

            (h) ESCROW. Upon issuance, the certificates for Restricted Shares
shall be deposited in escrow with the Company to be held in accordance with the
provisions of this Agreement. Any new, substituted or additional securities or
other property described in Subsection (f) above shall immediately be delivered
to the Company to be held in escrow, but only to the extent the Shares are at
the time Restricted Shares. All regular cash dividends on Restricted Shares (or
other securities at the time held in escrow) shall be paid directly to the
Optionee and shall not be held in escrow. Restricted Shares, together with any
other assets or securities held in escrow hereunder, shall be (i) surrendered to
the Company for repurchase and cancellation upon the Company's exercise of its
Right of Repurchase or Right of First Refusal or (ii) released to the Optionee
upon the Optionee's request to the extent the Shares are no longer Restricted
Shares (but not more frequently than once every six months). In any event, all
Shares which have vested (and any other vested assets and securities
attributable thereto) shall be released within 60 days after the earlier of (i)
the Optionee's cessation of Service or (ii) the lapse of the Right of First
Refusal.

SECTION 8. RIGHT OF FIRST REFUSAL.

            (a) RIGHT OF FIRST REFUSAL. In the event that the Optionee proposes
to sell, pledge or otherwise transfer to a third party any Shares acquired under
this Agreement, or any interest in such Shares, the Company shall have the Right
of First Refusal with respect to all (and not less than all) of such Shares. If
the Optionee desires to transfer Shares acquired under this

                                       6
<PAGE>   22
Agreement, the Optionee shall give a written Transfer Notice to the Company
describing fully the proposed transfer, including the number of Shares proposed
to be transferred, the proposed transfer price, the name and address of the
proposed Transferee and proof satisfactory to the Company that the proposed sale
or transfer will not violate any applicable federal or state securities laws.
The Transfer Notice shall be signed both by the Optionee and by the proposed
Transferee and must constitute a binding commitment of both parties to the
transfer of the Shares. The Company shall have the right to purchase all, and
not less than all, of the Shares on the terms of the proposal described in the
Transfer Notice (subject, however, to any change in such terms permitted under
Subsection (b) below) by delivery of a notice of exercise of the Right of First
Refusal within 30 days after the date when the Transfer Notice was received by
the Company. The Company's rights under this Subsection (a) shall be freely
assignable, in whole or in part.

            (b) TRANSFER OF SHARES. If the Company fails to exercise its Right
of First Refusal within 30 days after the date when it received the Transfer
Notice, the Optionee may, not later than 90 days following receipt of the
Transfer Notice by the Company, conclude a transfer of the Shares subject to the
Transfer Notice on the terms and conditions described in the Transfer Notice,
provided that any such sale is made in compliance with applicable federal and
state securities laws and not in violation of any other contractual restrictions
to which the Optionee is bound. Any proposed transfer on terms and conditions
different from those described in the Transfer Notice, as well as any subsequent
proposed transfer by the Optionee, shall again be subject to the Right of First
Refusal and shall require compliance with the procedure described in Subsection
(a) above. If the Company exercises its Right of First Refusal, the parties
shall consummate the sale of the Shares on the terms set forth in the Transfer
Notice within 60 days after the date when the Company received the Transfer
Notice (or within such longer period as may have been specified in the Transfer
Notice); provided, however, that in the event the Transfer Notice provided that
payment for the Shares was to be made in a form other than cash or cash
equivalents paid at the time of transfer, the Company shall have the option of
paying for the Shares with cash or cash equivalents equal to the present value
of the consideration described in the Transfer Notice.

            (c) ADDITIONAL SHARES OR SUBSTITUTED SECURITIES. In the event of the
declaration of a stock dividend, the declaration of an extraordinary dividend
payable in a form other than stock, a spin-off, a stock split, an adjustment in
conversion ratio, a recapitalization or a similar transaction affecting the
Company's outstanding securities without receipt of consideration, any new,
substituted or additional securities or other property (including money paid
other than as an ordinary cash dividend) which are by reason of such transaction
distributed with respect to any Shares subject to this Section 8 or into which
such Shares thereby become convertible shall immediately be subject to this
Section 8. Appropriate adjustments to reflect the distribution of such
securities or property shall be made to the number and/or class of the Shares
subject to this Section 8.

            (d) TERMINATION OF RIGHT OF FIRST REFUSAL. Any other provision of
this Section 8 notwithstanding, in the event that the Stock is readily tradable
on an established securities market when the Optionee desires to transfer
Shares, the Company shall have no Right of First Refusal, and the Optionee shall
have no obligation to comply with the procedures prescribed by Subsections (a)
and (b) above.

                                       7
<PAGE>   23
            (e) PERMITTED TRANSFERS. This Section 8 shall not apply to (i) a
transfer by beneficiary designation, will or intestate succession or (ii) a
transfer to the Optionee's spouse, children or grandchildren or to a trust
established by the Optionee for the benefit of the Optionee or the Optionee's
spouse, children or grandchildren, provided in either case that the Transferee
agrees in writing on a form prescribed by the Company to be bound by all
provisions of this Agreement. If the Optionee transfers any Shares acquired
under this Agreement, either under this Subsection (e) or after the Company has
failed to exercise the Right of First Refusal, then this Section 8 shall apply
to the Transferee to the same extent as to the Optionee.

            (f) TERMINATION OF RIGHTS AS SHAREHOLDER. If the Company makes
available, at the time and place and in the amount and form provided in this
Agreement, the consideration for the Shares to be purchased in accordance with
this Section 8, then after such time the person from whom such Shares are to be
purchased shall no longer have any rights as a holder of such Shares (other than
the right to receive payment of such consideration in accordance with this
Agreement). Such Shares shall be deemed to have been purchased in accordance
with the applicable provisions hereof, whether or not the certificate(s)
therefor have been delivered as required by this Agreement.

SECTION 9. LEGALITY OF INITIAL ISSUANCE.

            No Shares shall be issued upon the exercise of this option unless
and until the Company has determined that:

            (a) It and the Optionee have taken any actions required to register
the Shares under the Securities Act or to perfect an exemption from the
registration requirements thereof;

            (b) Any applicable listing requirement of any stock exchange or
other securities market on which Stock is listed has been satisfied; and

            (c) Any other applicable provision of state or federal law has been
satisfied.

SECTION 10. NO REGISTRATION RIGHTS.

               The Company may, but shall not be obligated to, register or
qualify the sale of Shares under the Securities Act or any other applicable law.
The Company shall not be obligated to take any affirmative action in order to
cause the sale of Shares under this Agreement to comply with any law.

SECTION 11. RESTRICTIONS ON TRANSFER.

            (a) SECURITIES LAW RESTRICTIONS. Regardless of whether the offering
and sale of Shares under the Plan have been registered under the Securities Act
or have been registered or qualified under the securities laws of any state, the
Company at its discretion may impose restrictions upon the sale, pledge or other
transfer of such Shares (including the placement of appropriate legends on stock
certificates or the imposition of stop-transfer instructions) if, in the
judgment of the Company, such restrictions are necessary or desirable in order
to achieve compliance with the Securities Act, the securities laws of any state
or any other law.

                                       8
<PAGE>   24
            (b) MARKET STAND-OFF. In connection with any underwritten public
offering by the Company of its equity securities pursuant to an effective
registration statement filed under the Securities Act, including the Company's
initial public offering, the Optionee shall not directly or indirectly sell,
make any short sale of, loan, hypothecate, pledge, offer, grant or sell any
option or other contract for the purchase of, purchase any option or other
contract for the sale of, or otherwise dispose of or transfer, or agree to
engage in any of the foregoing transactions with respect to, any Shares acquired
under this Agreement without the prior written consent of the Company or its
underwriters. Such restriction (the "Market Stand-Off") shall be in effect for
such period of time following the date of the final prospectus for the offering
as may be requested by the Company or such underwriters. In no event, however,
shall such period exceed 180 days. The Market Stand-Off shall in any event
terminate two years after the date of the Company's initial public offering. In
the event of the declaration of a stock dividend, a spin-off, a stock split, an
adjustment in conversion ratio, a recapitalization or a similar transaction
affecting the Company's outstanding securities without receipt of consideration,
any new, substituted or additional securities which are by reason of such
transaction distributed with respect to any Shares subject to the Market
Stand-Off, or into which such Shares thereby become convertible, shall
immediately be subject to the Market Stand-Off. In order to enforce the Market
Stand-Off, the Company may impose stop-transfer instructions with respect to the
Shares acquired under this Agreement until the end of the applicable stand-off
period. The Company's underwriters shall be beneficiaries of the agreement set
forth in this Subsection (b). This Subsection (b) shall not apply to Shares
registered in the public offering under the Securities Act, and the Optionee
shall be subject to this Subsection (b) only if the directors and officers of
the Company are subject to similar arrangements.

            (c) INVESTMENT INTENT AT GRANT. The Optionee represents and agrees
that the Shares to be acquired upon exercising this option will be acquired for
investment, and not with a view to the sale or distribution thereof.

            (d) INVESTMENT INTENT AT EXERCISE. In the event that the sale of
Shares under the Plan is not registered under the Securities Act but an
exemption is available which requires an investment representation or other
representation, the Optionee shall represent and agree at the time of exercise
that the Shares being acquired upon exercising this option are being acquired
for investment, and not with a view to the sale or distribution thereof, and
shall make such other representations as are deemed necessary or appropriate by
the Company and its counsel.

            (e) LEGENDS. All certificates evidencing Shares purchased under this
Agreement shall bear the following legend:

        "THE SHARES REPRESENTED HEREBY MAY NOT BE SOLD, ASSIGNED, TRANSFERRED,
        ENCUMBERED OR IN ANY MANNER DISPOSED OF, EXCEPT IN COMPLIANCE WITH THE
        TERMS OF A WRITTEN AGREEMENT BETWEEN THE COMPANY AND THE REGISTERED
        HOLDER OF THE SHARES (OR THE PREDECESSOR IN INTEREST TO THE SHARES).
        SUCH AGREEMENT GRANTS TO THE COMPANY CERTAIN RIGHTS OF FIRST REFUSAL
        UPON AN ATTEMPTED TRANSFER OF THE SHARES AND CERTAIN REPURCHASE RIGHTS
        UPON TERMINATION OF SERVICE WITH THE COMPANY. THE

                                       9
<PAGE>   25
        SECRETARY OF THE COMPANY WILL UPON WRITTEN REQUEST FURNISH A COPY OF
        SUCH AGREEMENT TO THE HOLDER HEREOF WITHOUT CHARGE."

All certificates evidencing Shares purchased under this Agreement in an
unregistered transaction shall bear the following legend (and such other
restrictive legends as are required or deemed advisable under the provisions of
any applicable law):

        "THE SHARES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE
        SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE SOLD, PLEDGED, OR
        OTHERWISE TRANSFERRED WITHOUT AN EFFECTIVE REGISTRATION THEREOF UNDER
        SUCH ACT OR AN OPINION OF COUNSEL, SATISFACTORY TO THE COMPANY AND ITS
        COUNSEL, THAT SUCH REGISTRATION IS NOT REQUIRED."

            (f) REMOVAL OF LEGENDS. If, in the opinion of the Company and its
counsel, any legend placed on a stock certificate representing Shares sold under
this Agreement is no longer required, the holder of such certificate shall be
entitled to exchange such certificate for a certificate representing the same
number of Shares but without such legend.

            (g) ADMINISTRATION. Any determination by the Company and its counsel
in connection with any of the matters set forth in this Section 11 shall be
conclusive and binding on the Optionee and all other persons.

SECTION 12. ADJUSTMENT OF SHARES.

               In the event of any transaction described in Section 8(a) of the
Plan, the terms of this option (including, without limitation, the number and
kind of Shares subject to this option and the Exercise Price) shall be adjusted
as set forth in Section 8(a) of the Plan. In the event that the Company is a
party to a merger or consolidation, this option shall be subject to the
agreement of merger or consolidation, as provided in Section 8(b) of the Plan.

SECTION 13.   MISCELLANEOUS PROVISIONS.

            (a) RIGHTS AS A SHAREHOLDER. Neither the Optionee nor the Optionee's
representative shall have any rights as a shareholder with respect to any Shares
subject to this option until the Optionee or the Optionee's representative
becomes entitled to receive such Shares by filing a notice of exercise and
paying the Purchase Price pursuant to Sections 4 and 5.

            (b) NO RETENTION RIGHTS. Nothing in this option or in the Plan shall
confer upon the Optionee any right to continue in Service for any period of
specific duration or interfere with or otherwise restrict in any way the rights
of the Company (or any Parent or Subsidiary employing or retaining the Optionee)
or of the Optionee, which rights are hereby expressly reserved by each, to
terminate his or her Service at any time and for any reason, with or without
cause.

            (c) NOTICE. Any notice required by the terms of this Agreement shall
be given in writing and shall be deemed effective upon personal delivery or upon
deposit with the United

                                       10
<PAGE>   26
States Postal Service, by registered or certified mail, with postage and fees
prepaid. Notice shall be addressed to the Company at its principal executive
office and to the Optionee at the address that he or she most recently provided
to the Company.

            (d) ENTIRE AGREEMENT. The Notice of Stock Option Grant, this
Agreement and the Plan constitute the entire contract between the parties hereto
with regard to the subject matter hereof. They supersede any other agreements,
representations or understandings (whether oral or written and whether express
or implied) which relate to the subject matter hereof.

            (e) CHOICE OF LAW. This Agreement shall be governed by, and
construed in accordance with, the laws of the State of California, as such laws
are applied to contracts entered into and performed in such State.

SECTION 14. DEFINITIONS.

            (a) "AGREEMENT" shall mean this Stock Option Agreement.

            (b) "BOARD OF DIRECTORS" shall mean the Board of Directors of the
Company, as constituted from time to time or, if a Committee has been appointed,
such Committee.

            (c) "CHANGE IN CONTROL" shall mean:

                   (i) The consummation of a merger or consolidation of the
        Company with or into another entity or any other corporate
        reorganization, if persons who were not shareholders of the Company
        immediately prior to such merger, consolidation or other reorganization
        own immediately after such merger, consolidation or other reorganization
        50% or more of the voting power of the outstanding securities of each of
        (A) the continuing or surviving entity and (B) any direct or indirect
        parent corporation of such continuing or surviving entity; or

                   (ii) The sale, transfer or other disposition of all or
        substantially all of the Company's assets.

A transaction shall not constitute a Change in Control if its sole purpose is to
change the state of the Company's incorporation or to create a holding company
that will be owned in substantially the same proportions by the persons who held
the Company's securities immediately before such transaction.

            (d) "CODE" shall mean the Internal Revenue Code of 1986, as amended.

            (e) "COMMITTEE" shall mean a committee of the Board of Directors, as
described in Section 2 of the Plan.

            (f) "COMPANY" shall mean ObjectSwitch Corporation, a California
corporation.

                                       11
<PAGE>   27
            (g) "CONSULTANT" shall mean a person who performs bona fide services
for the Company, a Parent or a Subsidiary as a consultant or advisor, excluding
Employees and Outside Directors.

            (h) "DATE OF GRANT" shall mean the date specified in the Notice of
Stock Option Grant, which date shall be the later of (i) the date on which the
Board of Directors resolved to grant this option or (ii) the first day of the
Optionee's Service.

            (i) "DISABILITY" shall mean that the Optionee is unable to engage in
any substantial gainful activity by reason of any medically determinable
physical or mental impairment.

            (j) "EMPLOYEE" shall mean any individual who is a common-law
employee of the Company, a Parent or a Subsidiary.

            (k) "EXERCISE PRICE" shall mean the amount for which one Share may
be purchased upon exercise of this option, as specified in the Notice of Stock
Option Grant.

            (l) "FAIR MARKET VALUE" shall mean the fair market value of a Share,
as determined by the Board of Directors in good faith. Such determination shall
be conclusive and binding on all persons.

            (m) "ISO" shall mean an employee incentive stock option described in
Section 422(b) of the Code.

            (n) "INVOLUNTARY TERMINATION" means the termination of the Service
of the Optionee which occurs by reason of:

                   (i) such individual's involuntary dismissal or discharge by
        the Company for reasons other than Misconduct, or

                   (ii) Optionee's voluntary resignation following (A) a change
        in his or her position with the Company which materially reduces his or
        her level of responsibility, (B) a reduction in his or her level of
        compensation (including base salary and participation in bonus or
        incentive programs) or (C) a relocation of such individual's place of
        employment by more than fifty (50) miles, provided and only if such
        change, reduction or relocation is effected by the Company without the
        individual's consent.

            (o) "MISCONDUCT" means the commission of any act of fraud,
embezzlement or dishonesty by the Optionee, any unauthorized use or disclosure
by such person of confidential information or trade secrets of the Company (or
any Parent or Subsidiary), or any other intentional misconduct by such person
adversely affecting the business or affairs of the Company (or any Parent or
Subsidiary) in a material manner. The foregoing definition shall not be deemed
to be inclusive of all the acts or omissions which the Company (or any Parent or
Subsidiary) may consider as grounds for the dismissal or discharge of any
Optionee or other person in the Service of the Company (or any Parent or
Subsidiary).

                                       12
<PAGE>   28
            (p) "NONSTATUTORY OPTION" shall mean a stock option not described in
Sections 422(b) or 423(b) of the Code.

            (q) "NOTICE OF STOCK OPTION GRANT" shall mean the document so
entitled to which this Agreement is attached.

            (r) "OPTIONEE" shall mean the person named in the Notice of Stock
Option Grant.

            (s) "OUTSIDE DIRECTOR" shall mean a member of the Board of Directors
who is not an Employee.

            (t) "PARENT" shall mean any corporation (other than the Company) in
an unbroken chain of corporations ending with the Company, if each of the
corporations other than the Company owns stock possessing 50% or more of the
total combined voting power of all classes of stock in one of the other
corporations in such chain.

            (u) "PLAN" shall mean the ObjectSwitch Corporation 2000 Key Employee
Stock Plan, as in effect on the Date of Grant.

            (v) "PURCHASE PRICE" shall mean the Exercise Price multiplied by the
number of Shares with respect to which this option is being exercised.

            (w) "RESTRICTED SHARE" shall mean a Share that is subject to the
Right of Repurchase.

            (x) "RIGHT OF FIRST REFUSAL" shall mean the Company's right of first
refusal described in Section 8.

            (y) "RIGHT OF REPURCHASE" shall mean the Company's right of
repurchase described in Section 7.

            (z) "SECURITIES ACT" shall mean the Securities Act of 1933, as
amended.

            (aa) "SERVICE" shall mean service as an Employee, Outside Director
or Consultant.

            (bb) "SHARE" shall mean one share of Stock, as adjusted in
accordance with Section 8 of the Plan (if applicable).

            (cc) "STOCK" shall mean the Common Stock of the Company, with a par
value of $0.001 per Share.

            (dd) "SUBSIDIARY" shall mean any corporation (other than the
Company) in an unbroken chain of corporations beginning with the Company, if
each of the corporations other than the last corporation in the unbroken chain
owns stock possessing 50% or more of the total combined voting power of all
classes of stock in one of the other corporations in such chain.

                                       13
<PAGE>   29
            (ee) "TRANSFEREE" shall mean any person to whom the Optionee has
directly or indirectly transferred any Share acquired under this Agreement.

            (ff) "TRANSFER NOTICE" shall mean the notice of a proposed transfer
of Shares described in Section 8.

                                       14
<PAGE>   30

             OBJECTSWITCH CORPORATION 2000 KEY EMPLOYEE STOCK PLAN:

                            SUMMARY OF STOCK PURCHASE

By your signature and the signature of the Company's representative below, you
and the Company agree that you are purchasing shares subject to the terms and
conditions of the 2000 Key Employee Stock Plan and the Stock Purchase Agreement,
both of which are attached to and made a part of this document.

<TABLE>
<CAPTION>
<S>                                                           <C>
         Name of Purchaser:                                   <<Name>>

         Total Number of Purchased Shares:                    <<TotalShares>>

         Purchase Price Per Share:                            $<<PricePerShare>>

         Date of Offer:                                       <<DatePurchase>>

         Date of Purchase:                                    <<DatePurchase>>

         Vesting Commencement Date:                           <<VestComDate>>

         Vesting Schedule:                                    The Right of Repurchase shall lapse with respect to
                                                              the first <<Percent>>% of the Purchased Shares when
                                                              the Purchaser completes <<CliffPeriod>> months of
                                                              continuous Service after the Vesting Commencement
                                                              Date. The Right of Repurchase shall lapse with
                                                              respect to an additional <<Fraction>>% of the
                                                              Purchased Shares when the Purchaser completes each
                                                              month of continuous Service thereafter.
</TABLE>

THE PURCHASE PRICE MUST BE PAID ON OR BEFORE THE DATE OF PURCHASE SET FORTH
ABOVE. IF YOU FAIL TO PAY ON TIME, THIS OFFER AUTOMATICALLY TERMINATES.

PURCHASER:                              OBJECTSWITCH CORPORATION

__________________________________      By:_____________________________________

                                        Title:__________________________________

<PAGE>   31

             OBJECTSWITCH CORPORATION 2000 KEY EMPLOYEE STOCK PLAN:

                            STOCK PURCHASE AGREEMENT

SECTION 1. ACQUISITION OF SHARES.

        (a) TRANSFER. On the terms and conditions set forth in the Summary of
Stock Purchase and this Agreement, the Company agrees to transfer to the
Purchaser the number of Shares set forth in the Summary of Stock Purchase. The
transfer shall occur at the offices of the Company on the date of purchase set
forth in the Summary of Stock Purchase or at such other place and time as the
parties may agree.

        (b) CONSIDERATION. The Purchaser agrees to pay the Purchase Price set
forth in the Summary of Stock Purchase for each Purchased Share. The Purchase
Price is agreed to be at least 100% of the Fair Market Value of the Purchased
Shares. Payment shall be made in cash or cash equivalents on the date of
purchase set forth in the Summary of Stock Purchase.

        (c) STOCK PLAN AND DEFINED TERMS. The transfer of the Purchased Shares
is subject to the Plan, a copy of which the Purchaser acknowledges having
received. The provisions of the Plan are incorporated into this Agreement by
this reference. Capitalized terms are defined in Section 12 of this Agreement.

SECTION 2. RIGHT OF REPURCHASE.

        (a) SCOPE OF REPURCHASE RIGHT. All Purchased Shares initially shall be
Restricted Shares and shall be subject to a right (but not an obligation) of
repurchase by the Company. The Purchaser shall not transfer, assign, encumber or
otherwise dispose of any Restricted Shares, except as provided in the following
sentence. The Purchaser may transfer Restricted Shares (i) by beneficiary
designation, will or intestate succession or (ii) to the Purchaser's spouse,
children or grandchildren or to a trust established by the Purchaser for the
benefit of the Purchaser or the Purchaser's spouse, children or grandchildren,
provided in either case that the Transferee agrees in writing on a form
prescribed by the Company to be bound by all provisions of this Agreement. If
the Purchaser transfers any Restricted Shares, then this Section 2 shall apply
to the Transferee to the same extent as to the Purchaser.

        (b) CONDITION PRECEDENT TO EXERCISE. The Right of Repurchase shall be
exercisable only during the 60-day period next following the date when the
Purchaser's Service terminates for any reason, with or without cause, including
(without limitation) death or disability.

        (c) LAPSE OF REPURCHASE RIGHT. The Right of Repurchase shall lapse with
respect to the Purchased Shares in accordance with the vesting schedule set
forth in the Summary of Stock Purchase. In addition, the Right of Repurchase
shall lapse and all of the remaining Restricted Shares shall become vested if
(i) the Company is subject to a Change in Control

<PAGE>   32

before the Purchaser's Service terminates and (ii) the Right of Repurchase is
not assigned to the entity that employs the Purchaser immediately after the
Change in Control or to its parent or subsidiary.

        (d) REPURCHASE COST. If the Company exercises the Right of Repurchase,
it shall pay the Purchaser an amount equal to the Purchase Price for each of the
Restricted Shares being repurchased.

        (e) EXERCISE OF REPURCHASE RIGHT. The Right of Repurchase shall be
exercisable only by written notice delivered to the Purchaser prior to the
expiration of the 60-day period specified in Subsection (b) above. The notice
shall set forth the date on which the repurchase is to be effected. Such date
shall not be more than 30 days after the date of the notice. The certificate(s)
representing the Restricted Shares to be repurchased shall, prior to the close
of business on the date specified for the repurchase, be delivered to the
Company properly endorsed for transfer. The Company shall, concurrently with the
receipt of such certificate(s), pay to the Purchaser the purchase price
determined according to Subsection (d) above. Payment shall be made in cash or
cash equivalents or by canceling indebtedness to the Company incurred by the
Purchaser in the purchase of the Restricted Shares. The Right of Repurchase
shall terminate with respect to any Restricted Shares for which it has not been
timely exercised pursuant to this Subsection (e).

        (f) ADDITIONAL SHARES OR SUBSTITUTED SECURITIES. In the event of the
declaration of a stock dividend, the declaration of an extraordinary dividend
payable in a form other than stock, a spin-off, a stock split, an adjustment in
conversion ratio, a recapitalization or a similar transaction affecting the
Company's outstanding securities without receipt of consideration, any new,
substituted or additional securities or other property (including money paid
other than as an ordinary cash dividend) which are by reason of such transaction
distributed with respect to any Restricted Shares or into which such Restricted
Shares thereby become convertible shall immediately be subject to the Right of
Repurchase. Appropriate adjustments to reflect the distribution of such
securities or property shall be made to the number and/or class of the
Restricted Shares. Appropriate adjustments shall also, after each such
transaction, be made to the price per share to be paid upon the exercise of the
Right of Repurchase in order to reflect any change in the Company's outstanding
securities effected without receipt of consideration therefor; provided,
however, that the aggregate purchase price payable for the Restricted Shares
shall remain the same.

        (g) TERMINATION OF RIGHTS AS SHAREHOLDER. If the Company makes
available, at the time and place and in the amount and form provided in this
Agreement, the consideration for the Restricted Shares to be repurchased in
accordance with this Section 2, then after such time the person from whom such
Restricted Shares are to be repurchased shall no longer have any rights as a
holder of such Restricted Shares (other than the right to receive payment of
such consideration in accordance with this Agreement). Such Restricted Shares
shall be deemed to have been repurchased in accordance with the applicable
provisions hereof, whether or not the certificate(s) therefor have been
delivered as required by this Agreement.

        (h) ESCROW. Upon issuance, the certificates for Restricted Shares shall
be deposited in escrow with the Company to be held in accordance with the
provisions of this Agreement. Any

                                       2
<PAGE>   33

new, substituted or additional securities or other property described in
Subsection (f) above shall immediately be delivered to the Company to be held in
escrow, but only to the extent the Purchased Shares are at the time Restricted
Shares. All regular cash dividends on Restricted Shares (or other securities at
the time held in escrow) shall be paid directly to the Purchaser and shall not
be held in escrow. Restricted Shares, together with any other assets or
securities held in escrow hereunder, shall be (i) surrendered to the Company for
repurchase and cancellation upon the Company's exercise of its Right of
Repurchase or Right of First Refusal or (ii) released to the Purchaser upon the
Purchaser's request to the extent the Purchased Shares are no longer Restricted
Shares (but not more frequently than once every six months). In any event, all
Purchased Shares which have vested (and any other vested assets and securities
attributable thereto) shall be released within 60 days after the earlier of (i)
the Purchaser's cessation of Service or (ii) the lapse of the Right of First
Refusal.

SECTION 3. RIGHT OF FIRST REFUSAL.

        (a) RIGHT OF FIRST REFUSAL. In the event that the Purchaser proposes to
sell, pledge or otherwise transfer to a third party any Purchased Shares, or any
interest in such Purchased Shares, the Company shall have the Right of First
Refusal with respect to all (and not less than all) of such Purchased Shares. If
the Purchaser desires to transfer Purchased Shares, the Purchaser shall give a
written Transfer Notice to the Company describing fully the proposed transfer,
including the number of Purchased Shares proposed to be transferred, the
proposed transfer price, the name and address of the proposed Transferee and
proof satisfactory to the Company that the proposed sale or transfer will not
violate any applicable federal or state securities laws. The Transfer Notice
shall be signed both by the Purchaser and by the proposed Transferee and must
constitute a binding commitment of both parties to the transfer of the Purchased
Shares. The Company shall have the right to purchase all, and not less than all,
of the Purchased Shares on the terms of the proposal described in the Transfer
Notice (subject, however, to any change in such terms permitted under Subsection
(b) below) by delivery of a notice of exercise of the Right of First Refusal
within 30 days after the date when the Transfer Notice was received by the
Company. The Company's rights under this Subsection (a) shall be freely
assignable, in whole or in part.

        (b) TRANSFER OF SHARES. If the Company fails to exercise its Right of
First Refusal within 30 days after the date when it received the Transfer
Notice, the Purchaser may, not later than 90 days following receipt of the
Transfer Notice by the Company, conclude a transfer of the Purchased Shares
subject to the Transfer Notice on the terms and conditions described in the
Transfer Notice, provided that any such sale is made in compliance with
applicable federal and state securities laws and not in violation of any other
contractual restrictions to which the Purchaser is bound. Any proposed transfer
on terms and conditions different from those described in the Transfer Notice,
as well as any subsequent proposed transfer by the Purchaser, shall again be
subject to the Right of First Refusal and shall require compliance with the
procedure described in Subsection (a) above. If the Company exercises its Right
of First Refusal, the parties shall consummate the sale of the Purchased Shares
on the terms set forth in the Transfer Notice within 60 days after the date when
the Company received the Transfer Notice (or within such longer period as may
have been specified in the Transfer Notice); provided, however, that in the
event the Transfer Notice provided that payment for the Purchased Shares was to
be made in a form other than cash or cash equivalents paid at the time

                                       3
<PAGE>   34

of transfer, the Company shall have the option of paying for the Purchased
Shares with cash or cash equivalents equal to the present value of the
consideration described in the Transfer Notice.

        (c) ADDITIONAL SHARES OR SUBSTITUTED SECURITIES. In the event of the
declaration of a stock dividend, the declaration of an extraordinary dividend
payable in a form other than stock, a spin-off, a stock split, an adjustment in
conversion ratio, a recapitalization or a similar transaction affecting the
Company's outstanding securities without receipt of consideration, any new,
substituted or additional securities or other property (including money paid
other than as an ordinary cash dividend) which are by reason of such transaction
distributed with respect to any Purchased Shares subject to this Section 3 or
into which such Purchased Shares thereby become convertible shall immediately be
subject to this Section 3. Appropriate adjustments to reflect the distribution
of such securities or property shall be made to the number and/or class of
Purchased Shares subject to this Section 3.

        (d) TERMINATION OF RIGHT OF FIRST REFUSAL. Any other provision of this
Section 3 notwithstanding, in the event that the Stock is readily tradable on an
established securities market when the Purchaser desires to transfer Purchased
Shares, the Company shall have no Right of First Refusal, and the Purchaser
shall have no obligation to comply with the procedures prescribed by Subsections
(a) and (b) above.

        (e) PERMITTED TRANSFERS. This Section 3 shall not apply to (i) a
transfer by beneficiary designation, will or intestate succession or (ii) a
transfer to the Purchaser's spouse, children or grandchildren or to a trust
established by the Purchaser for the benefit of the Purchaser or the Purchaser's
spouse, children or grandchildren, provided in either case that the Transferee
agrees in writing on a form prescribed by the Company to be bound by all
provisions of this Agreement. If the Purchaser transfers any Purchased Shares,
either under this Subsection (e) or after the Company has failed to exercise the
Right of First Refusal, then this Section 3 shall apply to the Transferee to the
same extent as to the Purchaser.

        (f) TERMINATION OF RIGHTS AS SHAREHOLDER. If the Company makes
available, at the time and place and in the amount and form provided in this
Agreement, the consideration for the Purchased Shares to be purchased in
accordance with this Section 3, then after such time the person from whom such
Purchased Shares are to be purchased shall no longer have any rights as a holder
of such Purchased Shares (other than the right to receive payment of such
consideration in accordance with this Agreement). Such Purchased Shares shall be
deemed to have been purchased in accordance with the applicable provisions
hereof, whether or not the certificate(s) therefor have been delivered as
required by this Agreement.

SECTION 4. OTHER RESTRICTIONS ON TRANSFER.

        (a) PURCHASER REPRESENTATIONS. In connection with the issuance and
acquisition of Shares under this Agreement, the Purchaser hereby represents and
warrants to the Company as follows:

               (i) The Purchaser is acquiring and will hold the Purchased Shares
        for investment for his or her account only and not with a view to, or
        for resale in connection with, any "distribution" thereof within the
        meaning of the Securities Act.

                                       4
<PAGE>   35

               (ii) The Purchaser understands that the Purchased Shares have not
        been registered under the Securities Act by reason of a specific
        exemption therefrom and that the Purchased Shares must be held
        indefinitely, unless they are subsequently registered under the
        Securities Act or the Purchaser obtains an opinion of counsel, in form
        and substance satisfactory to the Company and its counsel, that such
        registration is not required. The Purchaser further acknowledges and
        understands that the Company is under no obligation to register the
        Purchased Shares.

               (iii) The Purchaser is aware of the adoption of Rule 144 by the
        Securities and Exchange Commission under the Securities Act, which
        permits limited public resales of securities acquired in a non-public
        offering, subject to the satisfaction of certain conditions, including
        (without limitation) the availability of certain current public
        information about the issuer, the resale occurring only after the
        holding period required by Rule 144 has been satisfied, the sale
        occurring through an unsolicited "broker's transaction," and the amount
        of securities being sold during any three-month period not exceeding
        specified limitations. The Purchaser acknowledges and understands that
        the conditions for resale set forth in Rule 144 have not been satisfied
        and that the Company has no plans to satisfy these conditions in the
        foreseeable future.

               (iv) The Purchaser will not sell, transfer or otherwise dispose
        of the Purchased Shares in violation of the Securities Act, the
        Securities Exchange Act of 1934, or the rules promulgated thereunder,
        including Rule 144 under the Securities Act. The Purchaser agrees that
        he or she will not dispose of the Purchased Shares unless and until he
        or she has complied with all requirements of this Agreement applicable
        to the disposition of Purchased Shares and he or she has provided the
        Company with written assurances, in substance and form satisfactory to
        the Company, that (A) the proposed disposition does not require
        registration of the Purchased Shares under the Securities Act or all
        appropriate action necessary for compliance with the registration
        requirements of the Securities Act or with any exemption from
        registration available under the Securities Act (including Rule 144) has
        been taken and (B) the proposed disposition will not result in the
        contravention of any transfer restrictions applicable to the Purchased
        Shares under the Rules of the California Corporations Commissioner.

               (v) The Purchaser has been furnished with, and has had access to,
        such information as he or she considers necessary or appropriate for
        deciding whether to invest in the Purchased Shares, and the Purchaser
        has had an opportunity to ask questions and receive answers from the
        Company regarding the terms and conditions of the issuance of the
        Purchased Shares.

               (vi) The Purchaser is aware that his or her investment in the
        Company is a speculative investment which has limited liquidity and is
        subject to the risk of complete loss. The Purchaser is able, without
        impairing his or her financial condition, to hold the Purchased Shares
        for an indefinite period and to suffer a complete loss of his or her
        investment in the Purchased Shares.

        (b) SECURITIES LAW RESTRICTIONS. Regardless of whether the offering and
sale of Shares under the Plan have been registered under the Securities Act or
have been registered or

                                       5
<PAGE>   36

qualified under the securities laws of any state, the Company at its discretion
may impose restrictions upon the sale, pledge or other transfer of the Purchased
Shares (including the placement of appropriate legends on stock certificates or
the imposition of stop-transfer instructions) if, in the judgment of the
Company, such restrictions are necessary or desirable in order to achieve
compliance with the Securities Act, the securities laws of any state or any
other law.

        (c) MARKET STAND-OFF. In connection with any underwritten public
offering by the Company of its equity securities pursuant to an effective
registration statement filed under the Securities Act, including the Company's
initial public offering, the Purchaser shall not directly or indirectly sell,
make any short sale of, loan, hypothecate, pledge, offer, grant or sell any
option or other contract for the purchase of, purchase any option or other
contract for the sale of, or otherwise dispose of or transfer, or agree to
engage in any of the foregoing transactions with respect to, any Purchased
Shares without the prior written consent of the Company or its underwriters.
Such restriction (the "Market Stand-Off") shall be in effect for such period of
time following the date of the final prospectus for the offering as may be
requested by the Company or such underwriters. In no event, however, shall such
period exceed 180 days. The Market Stand-Off shall in any event terminate two
years after the date of the Company's initial public offering. In the event of
the declaration of a stock dividend, a spin-off, a stock split, an adjustment in
conversion ratio, a recapitalization or a similar transaction affecting the
Company's outstanding securities without receipt of consideration, any new,
substituted or additional securities which are by reason of such transaction
distributed with respect to any Shares subject to the Market Stand-Off, or into
which such Shares thereby become convertible, shall immediately be subject to
the Market Stand-Off. In order to enforce the Market Stand-Off, the Company may
impose stop-transfer instructions with respect to the Purchased Shares until the
end of the applicable stand-off period. The Company's underwriters shall be
beneficiaries of the agreement set forth in this Subsection (c). This Subsection
(c) shall not apply to Shares registered in the public offering under the
Securities Act, and the Purchaser shall be subject to this Subsection (c) only
if the directors and officers of the Company are subject to similar
arrangements.

        (d) RIGHTS OF THE COMPANY. The Company shall not be required to (i)
transfer on its books any Purchased Shares that have been sold or transferred in
contravention of this Agreement or (ii) treat as the owner of Purchased Shares,
or otherwise to accord voting, dividend or liquidation rights to, any transferee
to whom Purchased Shares have been transferred in contravention of this
Agreement.

SECTION 5. SUCCESSORS AND ASSIGNS.

            Except as otherwise expressly provided to the contrary, the
provisions of this Agreement shall inure to the benefit of, and be binding upon,
the Company and its successors and assigns and be binding upon the Purchaser and
the Purchaser's legal representatives, heirs, legatees, distributees, assigns
and transferees by operation of law, whether or not any such person has become a
party to this Agreement or has agreed in writing to join herein and to be bound
by the terms, conditions and restrictions hereof.

                                       6
<PAGE>   37

SECTION 6. NO RETENTION RIGHTS.

            Nothing in this Agreement or in the Plan shall confer upon the
Purchaser any right to continue in Service for any period of specific duration
or interfere with or otherwise restrict in any way the rights of the Company (or
any Parent or Subsidiary employing or retaining the Purchaser) or of the
Purchaser, which rights are hereby expressly reserved by each, to terminate his
or her Service at any time and for any reason, with or without cause.

SECTION 7. TAX ELECTION.

            The acquisition of the Purchased Shares may result in adverse tax
consequences that may be avoided or mitigated by filing an election under Code
Section 83(b). Such election may be filed only within 30 days after the date of
purchase set forth in the Summary of Stock Purchase. The form for making the
Code Section 83(b) election is attached to this Agreement as an Exhibit. THE
PURCHASER SHOULD CONSULT WITH HIS OR HER TAX ADVISOR TO DETERMINE THE TAX
CONSEQUENCES OF ACQUIRING THE PURCHASED SHARES AND THE ADVANTAGES AND
DISADVANTAGES OF FILING THE CODE SECTION 83(b) ELECTION. THE PURCHASER
ACKNOWLEDGES THAT IT IS HIS OR HER SOLE RESPONSIBILITY, AND NOT THE COMPANY'S,
TO FILE A TIMELY ELECTION UNDER CODE SECTION 83(b), EVEN IF THE PURCHASER
REQUESTS THE COMPANY OR ITS REPRESENTATIVES TO MAKE THIS FILING ON HIS OR HER
BEHALF.

SECTION 8. LEGENDS.

            All certificates evidencing Purchased Shares shall bear the
following legends:

        "THE SHARES REPRESENTED HEREBY MAY NOT BE SOLD, ASSIGNED, TRANSFERRED,
        ENCUMBERED OR IN ANY MANNER DISPOSED OF, EXCEPT IN COMPLIANCE WITH THE
        TERMS OF A WRITTEN AGREEMENT BETWEEN THE COMPANY AND THE REGISTERED
        HOLDER OF THE SHARES (OR THE PREDECESSOR IN INTEREST TO THE SHARES).
        SUCH AGREEMENT GRANTS TO THE COMPANY CERTAIN RIGHTS OF FIRST REFUSAL
        UPON AN ATTEMPTED TRANSFER OF THE SHARES AND CERTAIN REPURCHASE RIGHTS
        UPON TERMINATION OF SERVICE WITH THE COMPANY. THE SECRETARY OF THE
        COMPANY WILL UPON WRITTEN REQUEST FURNISH A COPY OF SUCH AGREEMENT TO
        THE HOLDER HEREOF WITHOUT CHARGE."

        "THE SHARES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE
        SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE SOLD, PLEDGED, OR
        OTHERWISE TRANSFERRED WITHOUT AN EFFECTIVE REGISTRATION THEREOF UNDER
        SUCH ACT OR AN OPINION OF COUNSEL, SATISFACTORY TO THE COMPANY AND ITS
        COUNSEL, THAT SUCH REGISTRATION IS NOT REQUIRED."

                                       7
<PAGE>   38

If required by the authorities of any state in connection with the issuance of
the Purchased Shares, the legend or legends required by such state authorities
shall also be endorsed on all such certificates.

SECTION 9. NOTICE.

            Any notice required by the terms of this Agreement shall be given in
writing and shall be deemed effective upon personal delivery or upon deposit
with the United States Postal Service, by registered or certified mail, with
postage and fees prepaid. Notice shall be addressed to the Company at its
principal executive office and to the Purchaser at the address that he or she
most recently provided to the Company.

SECTION 10. ENTIRE AGREEMENT.

            The Summary of Stock Purchase, this Agreement and the Plan
constitute the entire contract between the parties hereto with regard to the
subject matter hereof. They supersede any other agreements, representations or
understandings (whether oral or written and whether express or implied) which
relate to the subject matter hereof.

SECTION 11. CHOICE OF LAW.

            This Agreement shall be governed by, and construed in accordance
with, the laws of the State of California, as such laws are applied to contracts
entered into and performed in such State.

SECTION 12. DEFINITIONS.

        (a) "AGREEMENT" shall mean this Stock Purchase Agreement.

        (b) "BOARD OF DIRECTORS" shall mean the Board of Directors of the
Company, as constituted from time to time or, if a Committee has been appointed,
such Committee.

        (c) "CHANGE IN CONTROL" shall mean:

               (i) The consummation of a merger or consolidation of the Company
        with or into another entity or any other corporate reorganization, if
        persons who were not shareholders of the Company immediately prior to
        such merger, consolidation or other reorganization own immediately after
        such merger, consolidation or other reorganization 50% or more of the
        voting power of the outstanding securities of each of (A) the continuing
        or surviving entity and (B) any direct or indirect parent corporation of
        such continuing or surviving entity; or

               (ii) The sale, transfer or other disposition of all or
        substantially all of the Company's assets.

                                       8
<PAGE>   39

A transaction shall not constitute a Change in Control if its sole purpose is to
change the state of the Company's incorporation or to create a holding company
that will be owned in substantially the same proportions by the persons who held
the Company's securities immediately before such transaction.

        (d) "CODE" shall mean the Internal Revenue Code of 1986, as amended.

        (e) "COMMITTEE" shall mean a committee of the Board of Directors, as
described in Section 2 of the Plan.

        (f) "COMPANY" shall mean ObjectSwitch Corporation, a California
corporation.

        (g) "CONSULTANT" shall mean a person who performs bona fide services for
the Company, a Parent or a Subsidiary as a consultant or advisor, excluding
Employees and Outside Directors.

        (h) "EMPLOYEE" shall mean any individual who is a common-law employee of
the Company, a Parent or a Subsidiary.

        (i) "FAIR MARKET VALUE" shall mean the fair market value of a Share, as
determined by the Board of Directors in good faith. Such determination shall be
conclusive and binding on all persons.

        (j) "OUTSIDE DIRECTOR" shall mean a member of the Board of Directors who
is not an Employee.

        (k) "PARENT" shall mean any corporation (other than the Company) in an
unbroken chain of corporations ending with the Company, if each of the
corporations other than the Company owns stock possessing 50% or more of the
total combined voting power of all classes of stock in one of the other
corporations in such chain.

        (l) "PLAN" shall mean the ObjectSwitch Corporation 2000 Key Employee
Stock Plan, as amended.

        (m) "PURCHASED SHARES" shall mean the Shares purchased by the Purchaser
pursuant to this Agreement.

        (n) "PURCHASE PRICE" shall mean the amount for which one Share may be
purchased pursuant to this Agreement, as specified in the Summary of Stock
Purchase.

        (o) "PURCHASER" shall mean the person named in the Summary of Stock
Purchase.

        (p) "RESTRICTED SHARE" shall mean a Purchased Share that is subject to
the Right of Repurchase.

        (q) "RIGHT OF FIRST REFUSAL" shall mean the Company's right of first
refusal described in Section 3.

                                       9
<PAGE>   40

        (r) "RIGHT OF REPURCHASE" shall mean the Company's right of repurchase
described in Section 2.

        (s) "SECURITIES ACT" shall mean the Securities Act of 1933, as amended.

        (t) "SERVICE" shall mean service as an Employee, Outside Director or
Consultant.

        (u) "SHARE" shall mean one share of Stock, as adjusted in accordance
with Section 8 of the Plan (if applicable).

        (v) "STOCK" shall mean the Common Stock of the Company, with a par value
of $0.001 per Share.

        (w) "SUBSIDIARY" shall mean any corporation (other than the Company) in
an unbroken chain of corporations beginning with the Company, if each of the
corporations other than the last corporation in the unbroken chain owns stock
possessing 50% or more of the total combined voting power of all classes of
stock in one of the other corporations in such chain.

        (x) "SUMMARY OF STOCK PURCHASE" shall mean the document so entitled to
which this Agreement is attached.

        (y) "TRANSFEREE" shall mean any person to whom the Purchaser has
directly or indirectly transferred any Purchased Share.

        (z) "TRANSFER NOTICE" shall mean the notice of a proposed transfer of
Purchased Shares described in Section 3.

                                       10
<PAGE>   41

                                                                       EXHIBIT I

                             SECTION 83(b) ELECTION

This statement is made under Section 83(b) of the Internal Revenue Code of 1986,
as amended, pursuant to Treasury Regulations Section 1.83-2.

(1)     The taxpayer who performed the services is:

        Name:

        Address:

        Social Security No.:

(2)     The property with respect to which the election is made is ______ shares
        of the common stock of ObjectSwitch Corporation.

(3)     The property was transferred on ________ __, ____.

(4)     The taxable year for which the election is made is the calendar year
        ____.

(5)     The property is subject to a repurchase right pursuant to which the
        issuer has the right to acquire the property at the original purchase
        price if for any reason taxpayer's service with the issuer is
        terminated. The issuer's repurchase right lapses in a series of
        installments over a ______-year period ending on ___________ ____,
        _____.

(6)     The fair market value of such property at the time of transfer
        (determined without regard to any restriction other than a restriction
        which by its terms will never lapse) is $___ per share.

(7)     The amount paid for such property is $____ per share.

(8)     A copy of this statement was furnished to ObjectSwitch Corporation, for
        whom taxpayer rendered the services underlying the transfer of such
        property.

(9)     This statement is executed on _______ __, ____.

___________________________________    _________________________________________
Spouse (if any)                        Taxpayer

This election must be filed with the Internal Revenue Service Center with which
the Purchaser files his or her Federal income tax returns and must be filed
within 30 days after the date of purchase. This filing should be made by
registered or certified mail, return receipt requested. The Purchaser must
retain two copies of the completed form for filing with his or her Federal and
state tax returns for the current tax year and an additional copy for his or her
records.

<PAGE>   42

                    OBJECTSWITCH CORPORATION 2000 STOCK PLAN
                         NOTICE OF STOCK OPTION EXERCISE

OPTIONEE INFORMATION:

<TABLE>
<S>                                             <C>
Name:   _________________________________       Social Security Number:________-_____-_______

Address:_________________________________       Employee Number:       ______________________

        _________________________________

OPTION INFORMATION:

Date of Grant:_____________________, 19_____    Type of Option: [ ] Nonstatutory (NSO) or
                                                                [ ] Incentive (ISO)
</TABLE>

Exercise Price per share: $_______________

Total number of shares of Common Stock of
ObjectSwitch Corporation (the
"Company") covered by option:                   __________ shares

EXERCISE INFORMATION:

Number of shares of Common Stock of the Company for which option is being
exercised now: ________. (These shares are referred to below as the "Purchased
Shares.")

Total Exercise Price for the Purchased Shares: $_________

Form of payment enclosed [CHECK ALL THAT APPLY]:

<TABLE>
<S>                                   <C>
[ ] Check for $___________,           [ ] Certificate(s) for ______ shares of Common Stock of the
    made payable to                       Company that I have owned for at least six months.
    "ObjectSwitch                         (These shares will be valued as of the date this notice
    Corporation"                          is received by the Company.)

[ ] Promissory Note for               [ ] Attestation Form covering ______ shares of Common Stock
    $___________                          of the Company. (These shares will be valued as of the
                                          date this notice is received by the Company.)

Names in which the Purchased Shares should be registered [YOU MUST CHECK ONE]:

[ ] In my name only

[ ] In the names of my spouse and myself as community          My spouse's name (if applicable):
    property                                                   ____________________________________

[ ] In the names of my spouse and myself as joint
    tenants with the right of survivorship
</TABLE>

The certificate for the Purchased           ___________________________________
Shares should be sent to the                ___________________________________
following address:                          ___________________________________

               YOU MUST SIGN THIS NOTICE ON THE SECOND PAGE BEFORE
                          SUBMITTING IT TO THE COMPANY.

<PAGE>   43

REPRESENTATIONS AND ACKNOWLEDGMENTS OF THE OPTIONEE:

1.  I represent and warrant to the Company that I am acquiring and will hold the
    Purchased Shares for investment for my account only, and not with a view to,
    or for resale in connection with, any "distribution" of the Purchased Shares
    within the meaning of the Securities Act of 1933, as amended (the
    "Securities Act").

2.  I understand that the Purchased Shares have not been registered under the
    Securities Act by reason of a specific exemption therefrom and that the
    Purchased Shares must be held indefinitely, unless they are subsequently
    registered under the Securities Act or I obtain an opinion of counsel (in
    form and substance satisfactory to the Company and its counsel) that
    registration is not required.

3.  I acknowledge that the Company is under no obligation to register the
    Purchased Shares.

4.  I am aware of the adoption of Rule 144 by the Securities and Exchange
    Commission under the Securities Act, which permits limited public resales of
    securities acquired in a non-public offering, subject to the satisfaction of
    certain conditions. These conditions include (without limitation) that
    certain current public information about the issuer is available, that the
    resale occurs only after the holding period required by Rule 144 has been
    satisfied, that the sale occurs through an unsolicited "broker's
    transaction" and that the amount of securities being sold during any
    three-month period does not exceed specified limitations. I understand that
    the conditions for resale set forth in Rule 144 have not been satisfied and
    that the Company has no plans to satisfy these conditions in the foreseeable
    future.

5.  I will not sell, transfer or otherwise dispose of the Purchased Shares in
    violation of the Securities Act, the Securities Exchange Act of 1934, or the
    rules promulgated thereunder, including Rule 144 under the Securities Act.

6.  I acknowledge that I have received and had access to such information as I
    consider necessary or appropriate for deciding whether to invest in the
    Purchased Shares and that I had an opportunity to ask questions and receive
    answers from the Company regarding the terms and conditions of the issuance
    of the Purchased Shares.

7.  I am aware that my investment in the Company is a speculative investment
    which has limited liquidity and is subject to the risk of complete loss. I
    am able, without impairing my financial condition, to hold the Purchased
    Shares for an indefinite period and to suffer a complete loss of my
    investment in the Purchased Shares.

8.  I acknowledge that the Purchased Shares remain subject to the Company's
    right of first refusal and may remain subject to the Company's right of
    repurchase at the exercise price, all in accordance with the applicable
    Notice of Stock Option Grant and Stock Option Agreement.

9.  I acknowledge that I am acquiring the Purchased Shares subject to all other
    terms of the Notice of Stock Option Grant and Stock Option Agreement.

10. I acknowledge that I have received a copy of the Company's memorandum
    regarding the federal income tax consequences of an option exercise and the
    tax election under section 83(b) of the Internal Revenue Code. In the event
    that I choose to make a section 83(b) election, I acknowledge that it is my
    responsibility--and not the Company's responsibility--to file the election
    in a timely manner, even if I ask the Company or its agents to make the
    filing on my behalf. I acknowledge that the Company has encouraged me to
    consult my own adviser to determine the tax consequences of acquiring the
    Purchased Shares at this time.

11. THE SALE OF THE PURCHASED SHARES HAS NOT BEEN QUALIFIED WITH THE
    COMMISSIONER OF CORPORATIONS OF THE STATE OF CALIFORNIA, AND THE ISSUANCE OF
    SUCH SHARES OR THE PAYMENT OR RECEIPT OF ANY PART OF THE CONSIDERATION
    THEREFOR PRIOR TO SUCH QUALIFICATION IS UNLAWFUL UNLESS THE SALE OF SUCH
    SHARES IS EXEMPT FROM QUALIFICATION BY SECTION 25100, 25102 OR 25105 OF THE
    CALIFORNIA CORPORATIONS CODE. THE RIGHTS OF ALL PARTIES TO THIS AGREEMENT
    ARE EXPRESSLY CONDITIONED UNLESS THE SALE IS SO EXEMPT.

12. I agree to seek the consent of my spouse to the extent required by the
    Company to enforce the foregoing.

SIGNATURE:                                   DATE:

______________________________________       ___________________________

                                       2
<PAGE>   44

                       FEDERAL INCOME TAX CONSEQUENCES AND
                             SECTION 83(b) ELECTION
                          (Current as of October 1998)

PURPOSE OF THIS MEMORANDUM

The purpose of this memorandum is to provide you with a brief summary of the tax
consequences of exercising your option. For a number of reasons, this memorandum
is no substitute for personal tax advice:

-   To make the memorandum short and readable, only the highlights are covered.
    Some tax rules are not addressed, even though they may be important in
    particular cases.

-   While the summary attempts to deal with the most common situations, your own
    tax situation may well be different from the norm.

-   State and foreign income taxes are not addressed at all, even though they
    could have a significant impact on your tax planning. Likewise, federal gift
    and estate taxes and state inheritance taxes are not discussed.

-   Tax planning involving incentive stock options is exceedingly complex, in
    part because of the possible application of the alternative minimum tax.

-   The memorandum assumes that you are paying the exercise price of your option
    in cash (or in the form of a full-recourse promissory note with an interest
    rate that meets IRS requirements). If you are paying the exercise price in
    the form of stock, you become subject to special rules that are not
    addressed here.

-   The tax rules change often, and the Company is not responsible for updating
    this summary.

FOR THESE REASONS, THE COMPANY STRONGLY ENCOURAGES YOU TO CONSULT YOUR OWN TAX
ADVISER BEFORE EXERCISING YOUR OPTION AND BEFORE MAKING A DECISION ABOUT FILING
OR NOT FILING A SECTION 83(b) ELECTION.

LIMIT ON ISO TREATMENT

The Notice of Stock Option Grant indicates whether your option is a nonstatutory
stock option (NSO) or an incentive stock option (ISO). The favorable tax
treatment for ISOs is limited, regardless of what the Notice of Stock Option
Grant indicates. Of the options that become exercisable in any calendar year,
only options covering the first $100,000 of stock are eligible for ISO
treatment. The excess over $100,000 automatically receives NSO treatment. For
this purpose, stock is valued at the time of grant. This means that the value is
generally equal to the exercise price.

                                       3
<PAGE>   45

For example, assume that you hold an option to buy 50,000 shares for $4 per
share. Assume further that the entire option is exercisable immediately after
the date of grant. (It is irrelevant when the underlying stock vests.) Only the
first 25,000 shares qualify for ISO treatment. (25,000 times $4 equals
$100,000.) The remaining 25,000 shares will be treated as if they had been
acquired by exercising an NSO. This is true regardless of when the option is
actually exercised; what matters is when it first could have been exercised.

EXERCISE OF NONSTATUTORY STOCK OPTION TO PURCHASE VESTED SHARES

The Notice of Stock Option Grant indicates whether your Purchased Shares are
already vested. Vested shares are no longer subject to the Company's right to
repurchase them at the exercise price, although they are still subject to the
Company's right of first refusal. If you know that your Purchased Shares are
already vested, there is no need to file a section 83(b) election.

If you are exercising an NSO to purchase vested shares, you will be taxed now.
You will recognize ordinary income in an amount equal to the difference between
(a) the fair market value of the Purchased Shares on the date of exercise and
(b) the exercise price you are paying. If you are an employee or former employee
of the Company, this amount is subject to withholding for income and payroll
taxes. Your tax basis in the Purchased Shares (to calculate capital gain when
you sell the shares) is equal to their fair market value on the date of
exercise.

EXERCISE OF NSO TO PURCHASE NON-VESTED SHARES

If you are exercising an NSO to purchase non-vested shares, and if you do not
file a timely election under section 83(b) of the Internal Revenue Code, then
you will not be taxed now. Instead, you will be taxed whenever an increment of
Purchased Shares vests--in other words, when the Company no longer has the right
to repurchase those shares at the exercise price. The Notice of Stock Option
Grant indicates when this occurs, generally over a period of several years.
Whenever an increment of Purchased Shares vests, you will recognize ordinary
income in an amount equal to the difference between (a) the fair market value of
those Purchased Shares on the date of vesting and (b) the exercise price you are
paying for those Purchased Shares. If you are an employee or former employee of
the Company, this amount will be subject to withholding for income and payroll
taxes. Your tax basis in the Purchased Shares (to calculate capital gain when
you sell the shares) will be equal to their fair market value on the date of
vesting.

If you are exercising an NSO to purchase non-vested shares, and if you file a
timely election under section 83(b) of the Internal Revenue Code, then you will
be taxed now. You will recognize ordinary income in an amount equal to the
difference between (a) the fair market value of the Purchased Shares on the date
of exercise and (b) the exercise price you are paying. If you are an employee or
former employee of the Company, this amount is subject to withholding for income
and payroll taxes. Your tax basis in the Purchased Shares (to calculate capital
gain when you sell the shares) is equal to their fair market value on the date
of exercise. Even if the fair market value of the Purchased Shares on the date
of exercise equals the exercise price (and thus no tax is payable), the 83(b)
election must be made in order to avoid having any subsequent appreciation taxed
as ordinary income at the time of vesting.

                                       4
<PAGE>   46

YOU MUST FILE AN 83(b) ELECTION WITH THE INTERNAL REVENUE SERVICE WITHIN 30 DAYS
AFTER THE NOTICE OF EXERCISE OF STOCK OPTION IS SIGNED. The 30-day filing period
cannot be extended. If you miss the deadline, you will be taxed as the Purchased
Shares vest, based on the value of the shares at that time. (See above.) The
form for making the 83(b) election is attached. Additional copies of the form
must be filed with the Company and with your tax return for the year in which
you make the election.

EXERCISE OF ISO AND ISO HOLDING PERIODS

If you are exercising an ISO, you will not be taxed under the regular tax rules
until you dispose of the Purchased Shares.(1) (The alternative minimum tax rules
are described below.) The tax treatment at the time of disposition depends on
how long you hold the shares. You will satisfy the ISO holding periods if you
hold the Purchased Shares until the later of the following dates:

-   The date two years after the ISO was granted, and

-   The date one year after the ISO is exercised.

DISPOSITION OF ISO SHARES

If you dispose of the Purchased Shares after satisfying both of the ISO holding
periods, then you will recognize only a long-term capital gain at the time of
disposition. The amount of the capital gain is equal to the difference between
(a) the sales proceeds and (b) the exercise price. In general, the maximum
marginal federal income tax rate on long-term capital gains is 20%.

If you dispose of the Purchased Shares before either or both of the ISO holding
periods are met, then you will recognize ordinary income at the time of
disposition. The calculation of the ordinary income amount depends on whether
the shares are vested at the time of exercise.

-   SHARES VESTED. If the shares are vested at the time of exercise, the amount
    of ordinary income will be equal to the difference between (a) the fair
    market value of the Purchased Shares on the date of exercise and (b) the
    exercise price. But if the disposition is an arm's length sale to an
    unrelated party, the amount of ordinary income will not exceed the total
    gain from the sale. Under current IRS rules, the ordinary income amount will
    not be subject to withholding for income or payroll taxes. Your tax basis in
    the Purchased Shares will be equal to their fair market value on the date of
    exercise. Any gain in excess of your basis will be taxed as a capital
    gain--either long-term or short-term, depending on how long you hold the
    Purchased Shares after the date of exercise.

-   SHARES NOT VESTED--NO 83(b) ELECTION FILED. If the Purchased Shares are not
    vested at the time of exercise, and if you do not file a timely election
    under section 83(b) of the Internal Revenue Code, then the amount of
    ordinary income will be equal to the difference between (a) the fair market
    value of the Purchased Shares on the date of vesting and (b) the exercise

-----------------
(1) Generally, a "disposition" of shares purchased under an ISO encompasses any
transfer of legal title, such as a transfer by sale, exchange or gift, but does
not include a transfer to your spouse, a transfer into joint ownership with
right of survivorship (if you remain one of the joint owners), a pledge, a
transfer by bequest or inheritance, or certain tax free exchanges permitted
under the Internal Revenue Code.

                                       5
<PAGE>   47

    price. But if the disposition is an arm's length sale to an unrelated party,
    the amount of ordinary income will not exceed the total gain from the sale.
    Under current IRS rules, the ordinary income amount will not be subject to
    withholding for income or payroll taxes. Your tax basis in the Purchased
    Shares will be equal to their fair market value on the date of vesting. Any
    gain in excess of your basis will be taxed as a capital gain--either
    long-term or short-term, depending on how long you hold the Purchased Shares
    after the date of vesting.

-   SHARES NOT VESTED--TIMELY 83(b) ELECTION FILED. If the shares are not vested
    at the time of exercise, and if you file a timely election under section
    83(b) of the Internal Revenue Code, then the amount of ordinary income will
    be equal to the difference between (a) the fair market value of the
    Purchased Shares on the date of exercise and (b) the exercise price. In
    other words, the 83(b) election causes the ordinary income to be calculated
    as if the shares were vested at the time of exercise. All other rules
    described above for the purchase of vested shares by exercising an ISO apply
    here as well. YOU MUST FILE AN 83(b) ELECTION WITH THE INTERNAL REVENUE
    SERVICE WITHIN 30 DAYS AFTER THE NOTICE OF EXERCISE OF STOCK OPTION IS
    SIGNED. The 30-day filing period cannot be extended. Note that, in the case
    of an ISO, the 83(b) election does not trigger an immediate tax; it merely
    affects how the ordinary income is calculated when you dispose of the
    Purchased Shares. If you miss the filing deadline, the amount of your
    ordinary income will be based on the value of the Purchased Shares at the
    time they vest. (See above.) The form for making the 83(b) election is
    attached. Additional copies of the form must be filed with the Company and
    with your tax return for the year in which you make the election.

You may not know at this time whether you will dispose of your Purchased Shares
before meeting the two holding periods. You should nevertheless consider filing
an 83(b) election. If you meet the holding periods, the election will be moot
for purposes of the regular tax system, since you will have no ordinary income.
(The effect of the election under the alternative minimum tax system is
discussed below.) If you do not satisfy the holding periods, then the election
will take effect and will limit your ordinary income to the gain that existed at
the time of exercise.

SUMMARY OF ALTERNATIVE MINIMUM TAX

The alternative minimum tax (AMT) must be paid if it exceeds your regular income
tax. The AMT is equal to 26% of your alternative minimum tax base up to $175,000
and 28% of the excess over $175,000. (In the case of married individuals filing
separately, the breakpoint is $87,500 rather than $175,000.) Your alternative
minimum tax base is equal to your alternative minimum taxable income (AMTI)
minus your exemption amount.

-   ALTERNATIVE MINIMUM TAXABLE INCOME. Your AMTI is equal to your regular
    taxable income, subject to certain adjustments and increased by items of tax
    preference. Among the many adjustments made in computing AMTI are the
    following:

        -    State and local income and property taxes are not allowed as a
             deduction.

        -    Miscellaneous itemized deductions are not allowed.

                                       6
<PAGE>   48

        -    Medical expenses are not allowed as a deduction until they exceed
             10% of adjusted gross income (as opposed to the 7.5% floor that
             applies to regular income taxes).

        -    Certain interest deductions are not allowed.

        -    The standard deduction and personal exemptions are not allowed.

        -    When an ISO is exercised, the spread is treated as if the option
             were an NSO. (See discussion below.)

-   EXEMPTION AMOUNT. Before AMT is calculated, AMTI is reduced by the exemption
    amount. The exemption amount is as follows:

<TABLE>
<S>                                    <C>                          <C>
        Joint Returns: $45,000         Single Returns: $33,750      Separate Returns: $22,500
</TABLE>

        The exemption amount is phased out by 25 cents for each $1 by which AMTI
        exceeds the following levels:

<TABLE>
<S>                                    <C>                          <C>
        Joint Returns: $150,000        Single Returns: $112,500     Separate Returns: $75,000
</TABLE>

        This means, for example, that the entire $45,000 exemption amount
        disappears for married individuals filing joint returns when AMTI
        reaches $330,000.

APPLICATION OF AMT WHEN ISO IS EXERCISED

As noted above, when an ISO is exercised, the spread is treated for AMT purposes
as if the option were an NSO. In other words, the spread is included in AMTI at
the time of exercise, unless the Purchased Shares are not yet vested at the time
of exercise. If the Purchased Shares are not yet vested, the value of the shares
minus the exercise price is included in AMTI when the shares vest. If you make
an election under section 83(b) within 30 days after exercise, then the spread
should be included in AMTI at the time of exercise. YOU MUST FILE AN 83(b)
ELECTION WITH THE INTERNAL REVENUE SERVICE WITHIN 30 DAYS AFTER THE NOTICE OF
EXERCISE OF STOCK OPTION IS SIGNED. The 30-day filing period cannot be extended.

A special rule applies if you dispose of the Purchased Shares in the same year
in which you exercised the ISO. If the amount you realize on the sale is less
than the value of the stock at the time of exercise, then the amount includible
in AMTI on account of the ISO exercise is limited to the gain realized on the
sale.(2)

To the extent that your AMT is attributable to the spread on exercising an ISO
(and certain other items), the AMT paid may be applied as a credit against your
regular income tax liability in future years. But this tax credit cannot reduce
your regular income tax liability in any future tax year below your AMT for that
year. The AMT credit may be carried forward indefinitely, but it

----------------
(2) This is similar to the rule that applies under the regular tax system in the
event of a disqualifying disposition of ISO stock. The amount of ordinary income
that must be recognized in that case generally does not exceed the amount of the
gain realized in the disposition.

                                       7
<PAGE>   49

may not be carried back. (In practice, many optionees who paid AMT upon
exercising an ISO find that they cannot fully use this tax credit for many
years, if at all.)

When Purchased Shares are sold, your basis for purposes of computing the capital
gain or loss under the AMT system is increased by the option spread that exists
at the time of exercise. Again, an ISO is treated under the AMT system much like
an NSO is treated under the regular tax system. But your basis in the ISO shares
for purposes of computing gain or loss under the regular tax system is equal to
the exercise price; it does not reflect any AMT that you pay on the spread at
exercise. Therefore, if you pay AMT in the year of the ISO exercise and regular
income tax in the year of selling the Purchased Shares, you could pay tax twice
on the same gain (except to the extent that you can use the AMT credit described
above).

                                       8
<PAGE>   50

                             SECTION 83(b) ELECTION

This statement is made under Section 83(b) of the Internal Revenue Code of 1986,
as amended, pursuant to Treasury Regulations Section 1.83-2.

        (1)  The taxpayer who performed the services is:

             Name:         ___________________________________

             Address:      ___________________________________

                           ___________________________________

             Social Security No.:_____________________________

        (2)  The property with respect to which the election is made is ______
             shares of the common stock of Object Switch Corporation

        (3)  The property was transferred on ________ __, _____.

        (4)  The taxable year for which the election is made is the calendar
             year _____.

        (5)  The property is subject to a repurchase right pursuant to which the
             issuer has the right to acquire the property at the original
             purchase price if for any reason taxpayer's service with the issuer
             is terminated. The issuer's repurchase right lapses in a series of
             installments over a ______-year period ending on _______ ___, ____.

        (6)  The fair market value of such property at the time of transfer
             (determined without regard to any restriction other than a
             restriction which by its terms will never lapse) is $_____ per
             share.

        (7)  The amount paid for such property is $_____ per share.

        (8)  A copy of this statement was furnished to Object Switch
             Corporation, for whom taxpayer rendered the services underlying the
             transfer of such property.

        (9)  This statement is executed on _______ __, _____.

__________________________________      _____________________________________
Signature of Spouse (if any)            Signature of Taxpayer

THIS ELECTION MUST BE FILED WITH THE INTERNAL REVENUE SERVICE CENTER WITH WHICH
THE OPTIONEE FILES HIS OR HER FEDERAL INCOME TAX RETURNS AND MUST BE FILED
WITHIN 30 DAYS AFTER THE DATE OF PURCHASE. THIS FILING SHOULD BE MADE BY
REGISTERED OR CERTIFIED MAIL, RETURN RECEIPT REQUESTED. THE OPTIONEE MUST RETAIN
TWO COPIES OF THE COMPLETED FORM FOR FILING WITH HIS OR HER FEDERAL AND STATE
TAX RETURNS FOR THE CURRENT TAX YEAR AND AN ADDITIONAL COPY FOR HIS OR HER
RECORDS.<PAGE>   1
                                                                   Exhibit 10.10

                            SIXTH AMENDMENT TO LEASE

        This SIXTH AMENDMENT TO LEASE ("Sixth Amendment") is made and entered
into as of the 24th day of April, 2000 by and between WHLW REAL ESTATE LIMITED
PARTNERSHIP, a Delaware limited partnership ("Landlord"), and AUTODESK, INC., a
California corporation ("Tenant").

                                   RECITALS:

        WHEREAS, Tenant and Landlord's predecessor-in-interest, Connecticut
General Life Insurance Company, a Connecticut corporation ("CIGNA"), entered
into that certain Office Lease dated August 2, 1993 (the "Original Lease"), for
that certain premises specified in the Basic Lease Information attached to the
Original Lease, in the Marin Executive Center (the "Building") located at 4000
Civic Center Drive in the City of San Rafael, County of Marin, State of
California; and

        WHEREAS, Tenant and Cigna entered into that certain First Amendment to
Lease Agreement dated as of February 14, 1994 (the "First Amendment") whereby
certain Expansion Space was incorporated within the Demised Premises and the
measurements of the Initial Premises were revised; and

        WHEREAS, Tenant and Cigna entered into that certain Second Amendment to
Lease dated as of December 22, 1995 (the "Second Amendment"), whereby certain
additional Expansion Space was incorporated within the Demised Premises; and

        WHEREAS, Landlord has succeeded to the interest of Cigna under the
Lease, First Amendment and Second Amendment; and

        WHEREAS, Landlord and Tenant entered into that certain Third Amendment
to Lease dated as of December 27, 1996 (the "Third Amendment"), whereby certain
additional Expansion Space was incorporated within the Demised Premises and a
portion of the Demised Premises was removed from the Demised Premises; and

        WHEREAS, Landlord and Tenant entered into that certain Fourth Amendment
to Lease dated as of December ___, 1997 (the "Fourth Amendment"), whereby
certain additional Expansion Space was incorporated within the Demised Premises;
and

        WHEREAS, Landlord and Tenant entered into that certain Fifth Amendment
to Lease dated as of March 16, 2000 (the "Fifth Amendment"), whereby the Suite
309 Expansion Space and the Suite 200 Expansion Space (collectively consisting
of 6,086 rentable square feet and collectively referred to herein as the
"200/309 Space") were incorporated within the Demised Premises thereby bringing
the total number of rentable square feet within the Demised Premises to 127,102
rentable square feet (the Original Lease, First Amendment, Second Amendment,
Third Amendment, Fourth Amendment and Fifth Amendment are sometimes collectively
referred to herein as the "Lease"); and

<PAGE>   2

        WHEREAS, Landlord and Tenant now desire to amend the Lease to (i) expand
the Demised Premises to include approximately 417 rentable square feet located
on the third floor of the Building, as more particularly described on Exhibit A
attached hereto, and commonly known as Suite 311 of the Building (the "Suite 311
Expansion Space"); (ii) extend the term of the Lease for all of the Demised
Premises except for the 200/309 Space and the Suite 311 Expansion Space (the
"200/309/311 Space") from December 22, 2000 to December 31, 2005, (iii) extend
the term of the Lease for the 200/309 Space from December 22, 2005 to December
31, 2005, (iv) to provide Tenant with one (1) five (5) year option to renew, and
(v) otherwise modify the Lease, all upon the terms and conditions set forth in
this Sixth Amendment; and

        WHEREAS, except as otherwise expressly provided herein to the contrary,
all capitalized terms used in this Sixth Amendment shall have the same meanings
given such terms in the Lease.

        NOW, THEREFORE, in consideration of the foregoing recitals and the
mutual covenants contained herein, and for other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties hereto agree as follows:

        1. Addition of Suite 311 Expansion Space. From and after the Suite 311
Expansion Space Commencement Date (as such term is defined below in this Section
1), the Demised Premises shall be expanded to include the Suite 311 Expansion
Space, thereby increasing the size of the Demised Premises to 127,519 rentable
square feet. The term of the Lease for the Suite 311 Expansion Space shall
expire on December 31, 2005 (the "Suite 311 Expansion Space Expiration Date").
As used herein the "Suite 311 Expansion Space Lease Term" shall mean the period
of time commencing on the Suite 311 Commencement Date and ending on the Suite
311 Expiration Date. Effective as of the Suite 311 Expansion Space Commencement
Date, the Suite 311 Expansion Space shall be added to the Demised Premises and
leased on the same terms and conditions set forth in the Lease, as amended by
this Sixth Amendment and the "Demised Premises" shall be re-defined so as to
include the Suite 311 Expansion Space. As used herein the "Suite 311 Expansion
Space Commencement Date" shall mean the earlier of (a) the date upon which
Tenant first commences to conduct business in the Suite 311 Expansion Space or
(b) October 1, 2000.

        1.1 Base Monthly Rent. During the Suite 311 Expansion Space Lease Term,
the Base Monthly Rent payable by Tenant for the Suite 311 Expansion Space shall
be as set forth in the following schedule:

<TABLE>
<CAPTION>
                                                               Monthly Base Rental
                                                                Rate Per Rentable
        Period of Suite 311                                   Square Foot of the
     Expansion Space Lease Term         Base Monthly Rent    Suite 311 Expansion Space
     --------------------------         -----------------    --------------------------
<S>                                     <C>                  <C>
     Suite 311 Expansion Space              $1,021.65                 $2.45
     Commencement Date -12/22/01
          12/23/01-12/22/02                 $1,050.84                 $2.52
         12/23/02 -12/22/03                 $1,084.20                 $2.60
</TABLE>

                                      -2-
<PAGE>   3

<TABLE>
<CAPTION>
                                                               Monthly Base Rental
                                                                Rate Per Rentable
        Period of Suite 311                                   Square Foot of the
     Expansion Space Lease Term         Base Monthly Rent    Suite 311 Expansion Space
     --------------------------         -----------------    --------------------------
<S>                                     <C>                  <C>
        12/23/03 -12/22/04                   $1,117.56                  $2.68

        12/23/04 -12/31/05                   $1,150.92                  $2.76
</TABLE>

               1.2 Tenant's Share; Base Year. Tenant's Share of Expenses and
Property Taxes for the Suite 311 Expansion Space shall be 0.313% and shall be
calculated separate and apart from Tenant's Share of Expenses for the original
Demised Premises (including, without limitation, the 200/309 Space). The Base
Year used to calculate Tenant's Share of Expenses and Property Taxes for the
Suite 311 Expansion Space shall be the calendar year 2001.

        2. Extension of Term.

               2.1 Extension of the Term for the Demised Premises Except for the
200/309/311 Space. The term of the Lease for all of the Demised Premises except
for the 200/309/311 Space, which is currently scheduled to expire on December
22, 2000, is hereby extended for an additional five (5) years and nine (9) days
(the "Extension Period") until December 31, 2005, unless sooner terminated in
accordance with the Lease, upon all of the terms and conditions set forth in the
Lease, except as specifically modified by this Sixth Amendment.

               2.2 Extension of the Term for the 200/309 Space. The term of the
Lease for the 200/309 Space, which is scheduled to expire on December 22, 2005,
is hereby extended for a period of nine (9) days (the "200/309 Space Extension
Period") until December 31, 2005, unless sooner terminated in accordance with
the Lease, upon all of the terms and conditions set forth in the Lease, except
as specifically modified by this Sixth Amendment.

        3. Base Monthly Rent.

               3.1 Base Monthly Rent for Demised Premises Except for the
200/309/311 Space. During the Extension Period, the Base Monthly Rent payable by
Tenant for the Demised Premises except for the 200/309/311 Space shall be as set
forth in the following schedule:

<TABLE>
<CAPTION>
                                                        Monthly Base Rental Rate Per
                                                            Rentable Square Foot
           Period of                                       of the Demised Premises
       Extension Period           Base Monthly Rent    Except for the 200/309/311 Space
       ----------------           -----------------    ---------------------------------
<S>                               <C>                  <C>
      12/23/00-12/22/01            $296,489.20                     $2.45
      12/23/01-12/22/02            $304,960.32                     $2.52
      12/23/02-12/22/03            $314,641.60                     $2.60
      12/23/03-12/22/04            $324,322.88                     $2.68
      12/23/04-12/31/05            $334,004.16                     $2.76
</TABLE>

                                      -3-
<PAGE>   4

               3.2 Base Monthly Rent for 200/309 Space. Notwithstanding the Base
Monthly Rent schedule set forth in Section 2.1 above, during the 200/309 Space
Extension Period Tenant shall pay Base Monthly Rent for the 200/309 Space in
accordance with Section 2 of the Fifth Amendment.

        4. Base Year. During the Extension Period, the Base Year used to
calculate Tenant's Share of Expenses and Property Taxes for the Demised Premises
and the Suite 311 Expansion Space except for the 200/309 Space shall be
calendar year 2001. Notwithstanding the change in the Base Year for the Demised
Premises except for the 200/309 Space, the Base Year used to calculate Tenant's
Share of Expenses and Property Taxes for the 200/309 Space during the lease
terms therefor, as extended by the 200/309 Space Extension Period, shall remain
calendar year 2000.

        5. Construction. Tenant shall be responsible for performing the work and
supplying the materials and labor to prepare the Demised Premises (including the
Suite 311 Expansion Space but excluding the 200/311 Space) for Tenant's use
and occupancy during the Extension Period as set forth in Exhibit B attached
hereto. Landlord shall have no obligation to construct or pay for any
improvements for the Demised Premises except as set forth in Exhibit B and shall
not be liable in any manner for any failure by Tenant to complete construction
in a timely manner. Tenant hereby acknowledges and agrees that Tenant shall
perform such work in and supply such materials and labor to the Demised Premises
(including the Suite 311 Expansion Space but excluding the 200/309 Space) while
Tenant is in possession of such space and that Tenant shall not be entitled to
any abatement of Rent in connection therewith.

       6. Tenant. Tenant shall have the right to construct a trench on the Site
in a location to be mutually agreed upon by Landlord and Tenant and install
certain connecting telecommunications equipment in the trench in order to
connect certain telecommunications equipment located on the property addressed
at 3950 Civic Center Drive, San Rafael, California to certain equipment in the
Demised Premises; provided, however, that such rights granted to Tenant are
subject to (a) the approval of all applicable governmental agencies, (b)
Tenant's compliance with all applicable laws, and (c) Landlord and Tenant
entering into a commercially reasonable license agreement which, among other
things, shall provide: (i) Landlord with the right to approve the size and
location of the trench, the specifications for the equipment to be installed in
the trench, and the contractors who will be performing such work on behalf of
the Tenant, (ii) that Landlord shall be reimbursed for the costs it incurs in
connection with Landlord's review of plans and drawings for Tenant's proposed
work and Landlord's oversight of the construction of such work, (iii) Landlord
with a commercially reasonable indemnity and releases of liability from Tenant;
(iv) that Tenant's right to construct the trench and to use the connecting
telecommunications equipment are subject to the reasonable rules and regulations
governing such construction and use which Landlord may establish from
time-to-time, and (v) upon Landlord's request, Tenant shall remove the
connecting telecommunications equipment from the trench and restore the portion
of the Site on which Tenant constructed the trench to the condition such portion
of the Site existed immediately prior to Tenant's installation of the trench.

                                      -4-
<PAGE>   5

        7. Option To Renew.

               7.1 Option Right. Landlord hereby grants Tenant one (1) option to
extend the Term of the Lease for all, but not less than all, of the Demised
Premises then leased by Tenant (which for purposes hereof, shall include the
200/309/311 Space) for a period of five (5) years (the "Option Term"), which
option shall be exercisable only by written Exercise Notice (as defined below)
delivered by Tenant to Landlord as provided below. Upon the proper exercise of
such option to extend, the term of the Lease for all of the Demised Premises
then leased to Tenant (and not any portion thereof) shall be extended for the
Option Term.

               7.2 Option Rent. The Base Monthly Rent payable by Tenant during
the Option Term (the "Option Rent") shall be equal to the greater of (i) the
"Fair Market Rental Rate" for the Demised Premises; or (ii) the Base Monthly
Rent payable by Tenant during the last year of the Extension Period. As used
herein, the "Fair Market Rental Rate" for purposes of determining the Base
Monthly Rent payable by Tenant during the Option Term shall mean the monthly
base rent at which non-equity tenants, as of the commencement of the Option
Tenant will be leasing non-sublease, non-equity, unencumbered space comparable
in size, location and quality to the Demised Premises for a comparable term,
which comparable space is located in the Building and in other comparable
first-class office buildings in the vicinity of the Building, taking into
account and adjusting the Base Year to be the calendar year in which the Option
Term commences, and taking into consideration all free rent and other
out-of-pocket concessions generally being granted at such time for such
comparable space for the Option Term (including, without limitation, any tenant
improvement allowance provided for such comparable space, with the amount of
such tenant improvement allowance to be provided for the Demised Premises during
the Option Term to be determined after taking into account the age, quality and
layout of the tenant improvements in the Demised Premises as of the commencement
of the Option Term. All other terms and conditions of the Lease shall apply
throughout the Option Term; however, Tenant shall, in no event, have the option
to extend the Lease Term beyond the Option Term described in Section 7.1 above.

               7.3 Exercise of Option. The option contained in this Section 7
shall be exercised by Tenant, if at all, only in the following manner: (i)
Tenant shall deliver written notice to Landlord not more than thirteen (l3)
months nor less than nine (9) months prior to the expiration of the Extension
Period stating that Tenant its option (the "Exercise Notice"). If Tenant
properly and timely provides the Exercise Notice, the Base Monthly Rent during
the Option Term shall be increased to the Option Rent. Landlord shall specify
its determination of the Option Rent not less than ninety calendar (90) days
prior to the commencement of the Option Term. If Tenant believes that the Option
Rent specified by Landlord exceeds the actual fair market rent for the Demised
Premises as of the commencement of the Option Term, then Tenant shall so notify
Landlord within twenty (20) business days following receipt of Landlord's notice
("Objection Notice"). If Tenant fails to provide an Objection Notice to Landlord
within said twenty (20) business days of receipt of Landlord's notice,
Landlord's determination of the Option Rent shall be final and binding upon the
parties.

               7.4 Arbitration of Option Rent. If the parties are unable to
agree upon the Option Rent within ten (10) business days after Landlord's
receipt of Tenant's Objection Notice, the Option Rent shall be determined as
follows:

                                      -5-
<PAGE>   6

                      (i) Within fifteen (l5) days after receipt of the
        Objection Notice, Tenant shall obtain and deliver in writing to Landlord
        a determination of the fair market rent for the Premises for a term
        equal to the Option Term from a broker ("Tenant's Broker") licensed in
        the State of California and engaged in the office brokerage business in
        Marin County for at least the immediately preceding five (5) years
        ("Broker Qualifications"). If Landlord accepts such determination, the
        Base Monthly Rent for the Option Term shall be increased to an amount
        equal to the amount determined by Tenant's Broker.

                      (ii) If Landlord does not accept such determination,
        within fifteen (15) days after receipt of the determination of Tenant's
        Broker, Landlord shall designate a broker ("Landlord's Broker") with the
        Broker Qualifications who shall deliver in writing to Tenant its
        determination of the fair market rent for the Premises for a term equal
        to the Option Term.

                      (iii) Landlord's Broker and Tenant's Broker shall name a
        third broker with the Broker Qualifications who shall be competent and
        impartial ("Third Broker"). The Third Broker, however selected, shall be
        a person who has not previously acted in any capacity for either
        Landlord or Tenant. The Third Broker shall choose one of the two
        estimates of fair market rent submitted by Landlord's Broker and
        Tenant's Broker, which must be the one that is closer to the fair market
        rent as determined by the Third Broker. The Third Broker's determination
        of fair market rent shall be binding upon Landlord and Tenant. If the
        Third Broker believes that expert advice would materially assist
        him/her, he/she may retain one or more qualified persons, including but
        not limited to legal counsel, brokers, architects or engineers, to
        provide such expert advice ("Experts").

                      (iv) Landlord shall pay the costs and fees of Landlord's
        Broker in connection with any determination hereunder, and Tenant shall
        pay the costs and fees of Tenant's Broker in connection with such
        determination. The costs and fees of the Third Broker and any Experts
        shall be paid one-half by Landlord and one-half by Tenant.

               7.5 Payment Until Option Rent is Determined. If the amount of the
fair market rent is not known as of the commencement of the respective option
term, then Tenant shall continue to pay the Base Monthly Rent in effect at the
expiration of the Tern until the Option Rent is determined. When such
determination is made, Tenant shall pay any deficiency to Landlord within
fifteen (15) days after receipt of demand.

               7.6 Minimum Base Monthly Rent, Notwithstanding any provision of
this Section, in no event shall the Base Monthly Rent payable during the Option
Term be less than the sum of (i) the Base Monthly Rent in effect immediately
prior to the expiration of the initial Term and (ii) the rent adjustments
payable by Tenant on a per square foot basis during the last Lease Year of the
initial Term.

               7.7 Suspension of Right to Extend Term of the Lease.
Notwithstanding anything in the foregoing to the contrary, at Landlord's option,
and in addition to all of

                                      -6-
<PAGE>   7

Landlord's remedies under the Lease, at law or in equity, the right to extend
the term of the Lease hereinabove granted to Tenant shall not be deemed to be
properly exercised if, as of the date Tenant delivers the Exercise Notice or as
of the date of the extension, Tenant is in default under this Lease, after
giving effect to notice and cure periods, if any. In addition, Tenant's right to
extend the term of the Lease is personal to the original Tenant executing this
Sixth Amendment, and may not be assigned or exercised, voluntarily or
involuntarily, by or to, any person or entity other than the original Tenant,
and shall only be available to and exercisable by the Tenant when the original
Tenant (or an entity affiliated with Tenant or which controls Tenant, is
controlled by Tenant or which is under common control with Tenant or which is
the result of a merger or consolidation with Tenant) is in actual and physical
possession of the entire Demised Premises, (including, without limitation, the
200/309/3 11 Space).

        8. Deletions. Sections 1.3, 1.6(c) and 1.8 of the Original Lease and
Section 7 of the First Amendment are hereby deleted in their entirety and are of
no further force or effect.

        9. Convenient Rent Schedule. Although (i) the Base Monthly Rent payable
by Tenant for the Demised Premises except for the 200/309/3 11 Space during the
Extension Period is set forth in Section 3.1 above, (ii) the Base Monthly Rent
payable by Tenant for the Suite 311 Expansion Space during the Suite 311
Expansion Space Lease Term is set forth in Section 1.1 above and (iii) the Base
Monthly Rent payable by Tenant for the 200/309 Space during the term of the
lease for the 200/309 Space and the 200/309 Space Extension Period is set forth
in Section 3.2 above, for the convenience of the parties, set forth below is the
schedule of the Base Monthly Rent payable by Tenant for the entirety of the
Demised Premises (including the 200/309/3 11 Space) during the Extension Period

<TABLE>
<CAPTION>
           Period                     Monthly Installment of Base Rent
           ------                     --------------------------------
<S>                                   <C>
     12/23/00 to 12/22/01                         $310,595.75
     12/23/01 to 12/22/02                         $319,096.06
     12/23/02 to 12/22/03                         $328,810.70
     12/23/03 to 12/22/04                         $338,525.34
     12/23/04 to 12/31/05                         $348,239.98
</TABLE>

        10. Brokers. Landlord and Tenant hereby represent and warrant that it
has not dealt with any broker in connection with this Sixth Amendment except for
Legacy Partners Commercial, Inc. and Colliers International (collectively, the
"Brokers"), and insofar as such party knows, no other broker negotiated or
participated in negotiations of this Sixth Amendment or is entitled to any
commission in connection herewith. Landlord agrees to pay the commission of the
Brokers pursuant to a separate agreement. Each party agrees to indemnify,
protect and defend the other party against and hold the other party harmless
from any and all claims, demands, losses, liabilities, lawsuits, judgments, and
costs and expenses (including without limitation reasonable attorneys' fees)
with respect to any leasing commissions or equivalent compensation alleged to be
owing on account of the indemnifying party's dealings with any real estate
broker or agent, other than the Brokers.

                                      -7-
<PAGE>   8

        11. No Further Modification. Except as set forth in this Sixth
Amendment, all of the terms and provisions of the Lease shall remain unmodified
and in full force and effect.

        IN WITNESS WHEREOF, Landlord and Tenant have executed this Sixth
Amendment as of the day and year first above written.

LANDLORD:                     WHLW REAL ESTATE LIMITED
                              PARTNERSHIP, a Delaware limited partnership

                              By: LEGACY PARTNERS COMMERCIAL, INC.,
                                  a Texas corporation, as agent and manager for
                                  Landlord

                                  By: /s/ BARRY DiRAIMONZO
                                     -------------------------------------------
                                     Name: Barry DiRaimonzo
                                          --------------------------------------
                                     Title:
                                           -------------------------------------

TENANT:                       AUTODESK, INC.,
                              a California corporation

                                  By: /s/ STEVE CAKEBREAD
                                     -------------------------------------------
                                     Name: Steve Cakebread
                                          --------------------------------------
                                     Title:
                                           -------------------------------------

                                  By: /s/ CAROL BARTZ
                                     -------------------------------------------
                                     Name: Carol Bartz
                                          --------------------------------------
                                     Title:
                                           -------------------------------------

                                      -8-
<PAGE>   9

                        [EXHIBITS INTENTIONALLY OMITTED]

<PAGE>   10

                            FIFTH AMENDMENT TO LEASE

        This FIFTH AMENDMENT TO LEASE ("Fifth Amendment") is made and entered
into as of the 16th day of March, 2000 by and between WHLW REAL ESTATE LIMITED
PARTNERSHIP, a Delaware limited partnership ("Landlord"), and AUTODESK, INC., a
California corporation ("Tenant").

                                   RECITALS:

        WHEREAS, Tenant and Landlord's predecessor-in-interest, Connecticut
General Life Insurance Company, a Connecticut corporation ("Cigna"), entered
into that certain Office Lease dated August 2, 1993 (the "Original Lease"), for
that certain premises specified in the Basic Lease Information attached to the
Original Lease, in the Marin Executive Center (the "Building") located at 4000
Civic Center Drive in the City of San Rafael, County of Marin, State of
California; and

        WHEREAS, Tenant and Cigna entered into that certain First Amendment to
Lease Agreement dated as of February 14, 1994 (the "First Amendment") whereby
certain Expansion Space was incorporated within the Demised Premises and the
measurements of the Initial Premises were revised; and

        WHEREAS, Tenant and Cigna entered into that certain Second Amendment to
Lease dated as of December 22, 1995 (the "Second Amendment"), whereby certain.
additional Expansion Space was incorporated within the Demised Premises; and

        WHEREAS, Landlord has succeeded to the interest of Cigna under the
Lease, First Amendment and Second Amendment; and

        WHEREAS, Landlord and Tenant entered into that certain Third Amendment
to Lease dated as of December 27, 1996 (the "Third Amendment"), whereby certain
additional Expansion Space was incorporated within the Demised Premises and a
portion of the Demised Premises was removed from the Demised Premises; and

        WHEREAS, Landlord and Tenant entered into that certain Fourth Amendment
to Lease dated as of December 1997 (the "Fourth Amendment"), whereby certain
additional Expansion Space was incorporated within the Demised Premises (the
Original Lease, First Amendment, Second Amendment, Third Amendment and Fourth
Amendment are sometimes collectively referred to herein as the "Lease"); and

        WHEREAS, Landlord and Tenant now desire to amend the Lease to (i) expand
the Demised Premises to include approximately 999 rentable square feet located
on the third (3rd) floor of the Building, as more particularly described on
Exhibit A attached hereto, and commonly known as Suite 309 of the Building (the
"Suite 309 Expansion Space" or the "Suite 309"), (ii) expand the Demised
Premises to include approximately 5,087 rentable square feet located on the
second (2nd) floor of the Building, as more particularly described on Exhibit B
attached hereto, and commonly known as Suite 200 of the Building (the "Suite 200

<PAGE>   11

Expansion Space" or the "Suite 200") and (iii) otherwise modify the Lease, all
upon the terms and conditions set forth in this Fifth Amendment (the Suite 200
Expansion Space and the Suite 309 Expansion Space are sometimes collectively
referred to herein as the "Expansion Space"); and

        WHEREAS, except as otherwise expressly provided herein to the contrary,
all capitalized terms used in this Fifth Amendment shall have the same meanings
given such terms in the Lease.

        NOW, THEREFORE, in consideration of the foregoing recitals and the
mutual covenants contained herein, and for other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties hereto agree as follows:

        1. Addition of Expansion Space. From and after the Suite 309 Expansion
Space Commencement Date (as such term is defined below in this Section 1), the
Demised Premises shall be expanded to include the Suite 309 Expansion Space,
thereby increasing the size of the Demised Premises to 122,015 rentable square
feet. From and after the Suite 200 Expansion Space Commencement Date (as such
term is defined below in this Section 1), the Demised Premises shall be expanded
to include the Suite 200 Expansion Space, thereby increasing the size of the
Demised Premises to 127,102 rentable square feet. The term of the Lease for the
Expansion Space shall expire on December 22, 2005 (the "Expansion Space
Expiration Date"). As used herein, the "Suite 309 Expansion Space Lease Term"
shall mean the period of time commencing on the Suite 309 Commencement Date and
ending on the Expansion Space Expiration Date. As used herein, the "Suite 200
Expansion Space Lease Term" shall mean the period of time commencing on the
Suite 200 Expansion Space Commencement Date and ending on the Expansion Space
Expiration Date. Effective as of the Suite 309 Expansion Space Commencement
Date, the Suite 309 Expansion Space shall be added to the Demised Premises and
leased on the same terms and conditions set forth in the Lease, as amended by
this Fifth Amendment and the "Demised Premises" shall be re-defined so as to
include the Suite 309 Expansion Space. Effective as of the Suite 200 Expansion
Space Commencement Date, the Suite 200 Expansion Space shall be added to the
Demised Premises and leased on the same terms and conditions set forth in the
Lease, as amended by this Fifth Amendment, and the "Demised Premises" shall be
re-defined so as to include the Suite 200 Expansion Space. As used herein the
Suite 309 Expansion Space Commencement Date shall mean the earlier of (a) the
date upon which Tenant first commences to conduct business in the Suite 309
Expansion Space or (b) March 1, 2000. As used herein, the Suite 200 Expansion
Space Commencement Date shall mean the earlier to occur of (a) the date upon
which Tenant first commences to conduct business in the Suite 200 Expansion
Space or (b) May 1, 2000.

        2. Base Rent. The Base Monthly Rent payable by Tenant for the Suite 309
Expansion Space shall equal to $2,147.85 (i.e., $2.15 per rentable square foot
of the Suite 309 Expansion Space per month); provided, however, that the Base
Monthly Rent payable by Tenant for the Suite 309 Expansion Space for the first
full calendar month of the Suite 309 Expansion Space Lease Term shall be
abated. The Base Monthly Rent payable by Tenant for the Suite 200 Expansion
Space shall equal $10,937.05 (i.e., $2.15 per rentable square foot of the Suite
200 Expansion Square per month); provided, however, that the Base Monthly Rent
payable by Tenant for the Suite 200 Expansion Space for the first two and half
calendar months of the Suite 200 Expansion Space Lease Tern shall be abated.

                                      -2-
<PAGE>   12

        3. Tenant's Share; Base Year. Tenant's Share of Expenses and Property
Taxes for the Suite 309 Expansion Space shall be calculated separate and apart
from Tenant's Share of Expenses and Property Taxes for the original Demised
Premises. Tenant's Share of Expenses and Property Taxes for the Suite 309
Expansion Space is 0.75%. Tenant's Share of Expenses and Property Taxes for the
Suite 200 Expansion Space shall be calculated separate and apart from the
original Demised Premises. Tenant's Share of Expenses and Property Taxes for the
Suite 200 Expansion Space is 3.8%. From and after the Suite 200 Space
Commencement Date, Tenant's Share of Expenses and Property Taxes for the Suite
309 Expansion Space and the Suite 200 Expansion Space will be calculated
together and together will be 4.55%. The Base Year used to calculate Tenant's
Share of Expenses and Property Taxes for the Expansion Space shall be the
calendar year 2000.

        4. Parking. Due to the addition of the Expansion Space to the Demised
Premises, from and after the Suite 200 Expansion Space Commencement Date, Tenant
shall rent additional parking passes at the ratio of the one (1) unreserved
parking passes for each 3,000 rentable square feet of the Expansion Space (i.e.,
2 additional parking passes). In addition, in connection with Tenant's execution
of this Fifth Amendment, in addition to the other reserved parking passes
granted to Tenant under the Lease, Tenant shall have the right to convert three
(3) of the unreserved parking passes it is leasing pursuant to this Lease, as
amended by this Fifth Amendment, to reserved parking passes.

        5. Construction. Tenant shall be responsible for performing the work and
supplying materials and labor to prepare the Expansion Space for Tenant's use
and occupancy as set forth in detail in Exhibit C attached hereto. Landlord
shall have no obligation to construct or pay for any initial improvements for
the Expansion Space and shall not be liable in any manner for any failure by
Tenant to complete construction in a timely manner, except as may be set forth
in Exhibit C.

        6. Deletions. Section 1.9 of the Original Lease is hereby deleted and is
of no further force or effect.

        7. Brokers. Landlord and Tenant hereby represent and warrant that it has
not dealt with any broker in connection with this Fifth Amendment except for
Legacy Partners Commercial, Inc. and Colliers International (collectively, the
"Brokers"), and insofar as such party knows, no other broker negotiated or
participated in negotiations of this Fifth Amendment or is entitled to any
commission in connection herewith. Each party agrees to indemnify, protect and
defend the other party against and hold the other party harmless from any and
all claims, demands, losses, liabilities, lawsuits, judgments, and costs and
expenses (including without limitation reasonable attorneys' fees) with respect
to any leasing commissions or equivalent compensation alleged to be owing on
account of the indemnifying party's dealings with any real estate broker or
agent, other than the Brokers.

        8. No Further Modification. Except as set forth in this Fifth Amendment,
all of the terms and provisions of the Lease shall remain unmodified and in full
force and effect.

                                      -3-
<PAGE>   13

        IN WITNESS WHEREOF, Landlord and Tenant have executed this Fifth
Amendment as of the day and year first above written.

        LANDLORD:             WHLW REAL ESTATE LIMITED
                              PARTNERSHIP, a Delaware limited partnership

                              By: LEGACY PARTNERS COMMERCIAL, INC.,
                                  a Texas corporation, as agent and manager for
                                  Landlord

                                  By: /s/ BARRY DiRAIMONZO
                                     -------------------------------------------
                                     Name: Barry DiRaimonzo
                                          --------------------------------------
                                     Title:
                                           -------------------------------------

       TENANT:                AUTODESK, INC.,
                              a California corporation

                                  By: /s/ STEVE MCMAHON
                                     -------------------------------------------
                                     Name:  Steve McMahon
                                          --------------------------------------
                                     Title: SVP, HR
                                           -------------------------------------

                                  By:
                                     -------------------------------------------
                                     Name:
                                          --------------------------------------
                                     Title:
                                           -------------------------------------

                                      -4-
<PAGE>   14

                        [EXHIBITS INTENTIONALLY OMITTED]

<PAGE>   15

                           FOURTH AMENDMENT TO LEASE

        THIS FOURTH AMENDMENT TO LEASE (the "Fourth Amendment") is made and
entered as of the 22 day of December, 1997, by and between Lincoln Property
Company M.S. Inc., as Manager and Agent for WHLW REAL ESTATE LIMITED
PARTNERSHIP, a Delaware limited partnership ("Landlord") and AUTODESK, INC., a
California corporation ("Tenant").

                                   WITNESSETH

        WHEREAS, Tenant and Connecticut General Life Insurance Company, a
Connecticut corporation ("Cigna") entered into that certain Office Lease dated
August 2, 1993 (the "Original Lease"), for that certain premises specified in
the Basic Lease Information attached to the Original Lease, in the Marin
Executive Center (the "Building") located at 4000 Civic Center Drive in the City
of San Rafael, County of Marin, State of California; and

        WHEREAS, Tenant and Cigna entered into that certain First Amendment to
Lease Agreement dated as of February 14, 1994 (the "First Amendment"), whereby
certain Expansion Space was incorporated within the Demised Premises and the
measurements of the Initial Premises were revised; and

        WHEREAS, Tenant and Cigna entered into that certain Second Amendment to
Lease dated as of December 22, 1995 (the "Second Amendment"), whereby certain
additional Expansion Space was incorporated within the Demised Premises; and

        WHEREAS, Landlord has succeeded to the interest of Cigna under the
Lease, First Amendment and Second Amendment; and

        WHEREAS, Landlord and Tenant entered into that certain Third Amendment
to Lease dated as of December 27, 1996 (the "Third Amendment"), whereby certain
additional Expansion Space was incorporated within the Demised Premises and a
portion of the Demised Premises was removed from the Demised Premises (the
Original Lease, First Amendment, Second Amendment and Third Amendment are
sometimes collectively referred to herein as the "Lease"); and

        WHEREAS, Tenant now desires to incorporate within the Demised Premises
an additional approximately 10,476 rentable square feet of space on the second
(2nd) floor of the Building, commonly known as Suite 210 ("Suite 210") and more
particularly described on the attached Exhibit "A", in accordance with the terms
of the Lease, as modified by this Fourth Amendment; and

        WHEREAS, Tenant is currently in possession of Suite 210 under a sublease
by and between PacifiCare, as sublandlord, and Tenant, as subtenant (the
"Sublease"), which Sublease Tenant represents and warrants to Landlord expires,
by its terms, on November 30, 1997, the same date of the expiration date of
PacifiCare's lease with Landlord for Suite 210. By entering into this Fourth
Amendment, Tenant is deemed to have accepted possession of Suite 210 as of the
Suite 210 Commencement Date (as defined below); and

        WHEREAS, Landlord and Tenant desire to further amend and modify certain
provisions of the Lease as more particularly described below in order to
accommodate the addition of Suite 210.

        NOW, THEREFORE, in consideration of the mutual benefits accruing to the
parties hereto and for other valuable consideration, the receipt and sufficiency
of which is hereby acknowledged, it is hereby agreed that the Lease shall be
amended in the following respects:

               1. Addition of Suite 210/Commencement Date. Pursuant to Article
1.3 of the Original Lease, Tenant does hereby exercise its Expansion Option with
respect to Suite 210. The parties shall confirm the measurement of the rentable
square feet of Suite 210 pursuant to Article 1.2 of the Original Lease. The
Commencement Date for Suite 210 shall be December 20, 1997 (the "Suite 210
Commencement Date"). Upon the Suite 210 Commencement Date, Suite 210 shall be
deemed to be a part of the Demised Premises, and except as otherwise provided

<PAGE>   16

in this Fourth Amendment, shall be leased upon, and subject to all of the terms,
covenants, and conditions of the Lease. Notwithstanding anything to the contrary
contained in the Lease, the Lease term for Suite 210 shall be coterminous with
the term of the Lease and thus shall expire on December 22, 2000 (the
"Expiration Date"), unless sooner terminated or extended in accordance with the
terms of the Lease.

        2. Base Monthly Rental. Beginning on the Suite 210 Commencement Date,
Tenant shall pay Base Monthly Rental for Suite 210 in an amount equal to $1.99
per rentable square foot of Suite 210 per month (i.e., $20,847.24).
Notwithstanding anything contained in Article 1.3(1) of the Original Lease to
the contrary, there shall be no abatement of the Base Monthly Rental payable for
Suite 210.

        3. Base Year/Tenant's Share. The Base Year with respect to Suite 210
shall be the calendar year 1998. Tenant's Share with respect to Suite 210 shall
be 7.86%.

        4. Tenant Improvements. Notwithstanding any provision of the Lease
(including Article 1.3 of the Original Lease), Tenant shall occupy Suite 210 in
its current "AS IS" condition without any obligation on Landlord's part to
construct or pay for any Base Building Work, tenant improvements or
refurbishment work in or for Suite 210 prior to delivering possession of Suite
210 to Tenant. Accordingly, the provisions of Article 1.3 of the Original Lease
and any Work Letter attached to the Lease are not applicable to Suite 210.
Notwithstanding the foregoing sentence, Landlord will provide Tenant with a
tenant improvement allowance ("Tenant Improvement Allowance") in the amount of
up to, but not exceeding, $3.86 per rentable square foot of Suite 210 (i.e.,
$40,437.36) and an additional allowance (the "Additional Allowance") in the
amount of up to, but not exceeding, $0.22 per square rentable square foot of
Suite 210 (i.e., $2,252.34) (the Tenant Improvement Allowance and Additional
Allowance shall collectively be referred to as the "Allowances"). Tenant may use
the Allowances to help pay for the cost of the tenant improvements and
alterations it desires to make Suite 210 and any other part of the Demised
Premises which Tenant leases in the Building at any time after the date hereof
and during the term of the Original Lease pursuant to the provisions of Article
4.1 of the Original Lease; provided, however, that (i) the Additional Allowance
shall only be used to pay costs and fees of the architect and engineers for the
plans for such tenant improvements and alterations, (ii) Tenant Improvement
Allowance shall not be used for any personal property of Tenant including but
not limited to telephone and data cabling or appliances, and iii) in the event
Tenant does not use the entire amount of the Allowances to pay for such tenant
improvement costs, Tenant shall not be entitled to any credits or refunds
thereof.

               4.1 Disbursements of Allowances. Landlord shall disburse the
Allowances on a progress payment basis (but not more frequently then once every
month) during the construction of the applicable tenant improvements and
alterations and after Landlord's receipt of any or all of the following as
applicable:

                      (i) Architect's Certificate of Payment, AIA Form G702;

                      (ii) A certificate subscribed by Tenant and approved by
        Landlord, setting forth the total cost of the work performed to date and
        the cost of all work performed since the last previous disbursement;

                      (iii) Either a Conditional Waiver and Release Upon
        Progress Payment or a Conditional Waiver and Release Upon Final Payment,
        as appropriate, in the form prescribed by California Civil Code section
        3262 ("Section 3262"), executed by the contractor intended to be paid
        out of the particular disbursement and covering all labor, services,
        equipment and materials performed or supplied by the contractor since
        the last previous disbursement; and

                      (iv) Either an Unconditional Waiver and Release Upon
        Progress Payment or an Unconditional Waiver and Release Upon Final
        Payment, as appropriate, in the form prescribed by Section 3262,
        executed by the contractor paid out of the last previous disbursement
        covering all labor, services, equipment and materials performed or
        supplied by the contractor prior to the last previous disbursements.

                                      -2-
<PAGE>   17

        The final request for disbursement shall include a current preliminary
        title report indicating that there are no liens against the Building
        arising out of the construction of such tenant improvements.

               5. Termination Fee. Article 1.9 of the Original Lease is hereby
amended so that the termination fee payable by Tenant equals the sum of (a) the
unamortized portion of the brokerage commissions paid or incurred by Landlord in
connection with this Fourth Amendment and the leasing of Suite 210; plus (b) the
unamortized portion of the Allowances provided by Landlord for Suite 210
pursuant to this Fourth Amendment. The brokerage commissions and Allowances for
Suite 210 shall be amortized on a straight-line basis over the scheduled
36-month initial lease term for Suite 210, together with interest at the rate of
ten percent (10%) per annum, and the unamortized portion thereof shall be
determined based upon the unexpired portion of such 36-month lease term for
Suite 210 as of September 30, 1999 had this Lease not been terminated pursuant
to Article 1.9 of the Original Lease. As soon as reasonably practicable
following the Suite 210 Commencement Date, Landlord shall deliver to Tenant a
written summary of the amount of the leasing commissions incurred by Landlord
for the leasing of Suite 210 to Tenant.

               6. Parking. In connection with the incorporation of Suite 210 to
the Demised Premises, effective from and after the Suite 210 Commencement Date,
pursuant to Section I(1) and Article 1.5 of the Original Lease, Tenant shall
rent an additional three (3) Reserved Parking Spaces which shall bring the total
number of Reserved Parking Spaces rented by Tenant pursuant to the Lease to
forty (40).

               7. Brokers. Landlord agrees to pay Colliers Advisory Group and
Lincoln Property Company Management Services, Inc. (collectively, "Brokers") a
commission in connection with this Fourth Amendment and the leasing of Suite 210
pursuant to a separate agreement between Landlord and Brokers. Tenant represents
and warrants to Landlord that Tenant has not had any discussions or negotiations
or otherwise dealt with any other real estate broker or agent other than Brokers
in connection with this Fourth Amendment or the leasing of Suite 210. Tenant
shall indemnify, defend, protect and hold Landlord harmless from and against any
and all costs, expenses, claims and liabilities (including costs of suit and
reasonable attorneys' fees) for any compensation, commission or fees claimed by
any other real estate broker or agent in connection with this Fourth Amendment
or its negotiation or the leasing of Suite 210 or its negotiation by reason of
any act of Tenant, except Damner Pike & Company and Seagate Properties, Inc.

               8. Tenant Certificate. Tenant hereby acknowledges that as of the
date on which Landlord and Tenant execute this Fourth Amendment, there is a deed
of trust encumbering, and in force against, the Demised Premises and the Site in
favor of General Electric Capital Corporation, a New York corporation (the
"Current Lender"). Simultaneously with Tenant's execution of this Fourth
Amendment, Tenant shall sign, notarize and deliver a subordination,
non-disturbance and attornment agreement substantially in the form of Exhibit
"B" attached hereto, entitled "Tenant Certificate." If Landlord at any time
during the term of the Lease causes the Demised Premises, the Building and/or
the Site to be encumbered by a new deed of trust or mortgage pursuant to which
the beneficiary of such deed of trust or mortgage is a party or entity other
than the Current Lender, the parties acknowledge and agree that the form of any
non-disturbance and attornment agreement that may be requested to be executed
and delivered by Tenant in connection therewith will not be the "Tenant
Certificate" attached to this Fourth Amendment as Exhibit "B". If the foregoing
occurs and/or if any party which acquires, or otherwise succeeds to, Landlord's
interest in the Demised Premises, the Building or the Site (including, without
limitation, any ground lessee) encumbers or places a lien against the Demised
Premises, the Building or the Site with a mortgage, deed of trust or similar
security instrument and the beneficiary thereof requires the Lease, as amended
hereby, to be subordinated to such encumbrance or lien, Landlord or the
successor of Landlord will use commercially reasonable efforts to provide to
Tenant a subordination, non-disturbance and attornment agreement in a form
reasonably acceptable to Landlord or such successor of Landlord, the subject
beneficiary and Tenant. If said subordination, non-disturbance and attornment
agreement is required and agreed upon by the aforesaid parties, Landlord or the
successor of Landlord, the subject beneficiary and Tenant shall cause any such
subordination, non-disturbance and attornment agreement to be executed,
acknowledged and recorded concurrently with, or as soon as practicable after,
the execution and recordation of any such lien, deed of trust or mortgage. In
addition to the

                                      -3-
<PAGE>   18

foregoing, if Landlord enters into a ground lease with regard to the Building
and/or the Site and such ground lessee requires the Lease, as amended hereby, to
be subordinated to such ground lease, the ground lessee and ground lessor will
use commercially reasonable efforts to provide to Tenant a subordination,
non-disturbance and attornment agreement in form reasonably acceptable to such
ground lessee, ground lessor, any beneficiary of ground lessee, and to Tenant.

               9. Defined Terms. Except as amended by this Fourth Amendment, all
of the capitalized terms used herein but not herein defined shall have the same
meanings ascribed to them in the Lease.

               10. Status of Lease. Except as amended by this Fourth Amendment,
the Lease remains unchanged, and as amended, all of the terms, covenants and
conditions of the Lease remain in full force and effect.

        IN WITNESS WHEREOF, the parties hereto have executed this Fourth
Amendment as of the day and year first above written.

"LANDLORD"                              WHLW REAL ESTATE LIMITED
                                        PARTNERSHIP, a Deleware limited
                                        partnership

                                        By: Lincoln Property Company Management
                                        Services, Inc. as Manager and Agent for
                                        Landlord

                                        By: /s/ D. ALLEN PALMER
                                           -------------------------------------
                                        Name: D. Allen Palmer
                                             -----------------------------------
                                        Title: Senior Vice President
                                              ----------------------------------

"TENANT"                                AUTODESK, INC.,
                                        a California corporation

                                        By: /s/  CAROL BARTZ
                                           -------------------------------------
                                        Name: Carol Bartz
                                             -----------------------------------
                                        Title: Chairman & CEO
                                              ----------------------------------

                                      -4-
<PAGE>   19

                            THIRD AMENDMENT TO LEASE

               THIS THIRD AMENDMENT TO LEASE (the "Third Amendment") is made and
entered as of the 27th day of December, 1996, by and between LINCOLN PROPERTY
COMPANY M.S., INC., as Manager for WHLW Real Estate Limited Partnership, a
Delaware Limited Partnership ("Landlord") and AUTODESK, INC., a California
corporation ("Tenant").

                                   WITNESSETH

               WHEREAS, Tenant and Connecticut General Life Insurance Company, a
Connecticut corporation ("Cigna") entered into that certain Office Lease dated
August 2, 1993 (the "Original Lease"), for that certain premises specified in
the Basic Lease Information attached to the Lease, in the Marin Executive Center
(the "Building") located at 4000 Civic Center Drive in the City of San Rafael,
County of Marin, State of California; and

               WHEREAS, Tenant and Cigna entered into that certain First
Amendment to Lease Agreement dated as of February 14, 1994 (the "First
Amendment"), whereby certain Expansion Space was incorporated within the Demised
Premises and the measurements of the Initial Premises were revised; and

               WHEREAS, Tenant and Cigna entered into that certain Second
Amendment to Lease dated as of December 22, 1995 (the "Second Amendment"),
whereby certain additional Expansion Space was incorporated within the Demised
Premises (the Original Lease, First Amendment and Second Amendment are sometimes
collectively referred to herein as the "Lease"); and

               WHEREAS, Tenant now desires to incorporate additional Expansion
Space within the Demised Premises in accordance with the terns of the Lease; and

               WHEREAS, Landlord and Tenant now desire to remove from the
Demised Premises a portion of Suite 302 located on the third floor of the
Building containing approximately 118 rentable square feet as described in
Exhibit "C", which Exhibit is attached hereto and incorporated herein (the
"Reduction Space"), and accordingly terminate the Lease with respect to the
Reduction Space;

               WHEREAS, Landlord and Tenant desire to further amend and modify
certain provisions of the Lease as more particularly described below in order to
accommodate the addition of the Expansion Space and the removal of the Reduction
Space;

               NOW, THEREFORE, in consideration of the mutual benefits accruing
to the parties hereto and for other valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, it is hereby agreed that the Lease
shall be amended in the following respects:

<PAGE>   20

        A. Expansion Space.

               1. Exercise of Expansion Option. Pursuant to Article 1.3 of the
Lease, Tenant does hereby exercise its Expansion Option with respect to two (2)
separate spaces, the first space consisting of 1,101 rentable square feet of
space located on the third floor of the Building ("Suite 300"), and is more
particularly described on the attached Exhibit "A-1", and the second space
consisting of 1,281 rentable square feet of space located on the second floor of
the Building ("Suite 204"), and is more particularly described on the attached
Exhibit "A-2", both of which Exhibits are hereby incorporated into this Third
Amendment. The parties shall confirm the measurement of the square footage of
each of Suite 300 and Suite 204 in accordance with the terms of Article 1.2 of
the Lease. Suite 300 and Suite 204 may be collectively referred to herein as the
"Suites" and individually as a "Suite".

               2. Expansion Space Term. In accordance with Article 1.3(2) of the
Lease, the Commencement Date for Suite 300 shall be sixty (60) days following
the date that Landlord delivers possession (as that term is defined in Paragraph
A.5 hereof) of Suite 300 to the Tenant (the "300 Commencement Date") and the
Commencement Date for Suite 204 shall be forty-five (45) days following the date
Landlord delivers possession (as defined in Paragraph A.5 hereof) of Suite 204
to the Tenant (the "204 Commencement Date"). The term for both Suites 204 and
300 shall be coterminous with the term of the Lease and thus shall expire on
December 22, 2000, unless extended in accordance with the terms of the Lease
(the "Expiration Date"). Subject to the abatement provisions in Paragraph A.5
below, Landlord shall not be liable to Tenant for any damages if Landlord is
unable to deliver possession of the applicable Suite to Tenant on or before such
applicable Commencement Date for any reason whatsoever (including delays in
vacation of Suite 204 by the existing tenant), and such failure shall not affect
the validity of the Lease, as amended hereby, nor the obligations of Tenant
under the Lease, as amended hereby. The Commencement Date for each such Suite
shall be specified by Landlord in a notice ("Notice") to be delivered by
Landlord to Tenant, which Notice shall be executed by Tenant and returned to
Landlord within five (5) days after Tenant's receipt thereof. Possession by
Tenant of any portion of a Suite prior to the applicable Commencement Date
therefor shall be subject to all of the provisions of the Lease, as amended
hereby, except that it shall not advance or extend such applicable Commencement
Date or the Expiration Date.

               3. Rent. Beginning on (a) the 300 Commencement Date, Tenant shall
pay Base Monthly Rental for Suite 300 in an amount equal to $1.91 per rentable
square foot of Suite 300 per month (i.e. $2,102.91) and (b) the 204 Commencement
Date, Tenant shall pay Base Monthly Rental for Suite 204 in an amount equal to
$1.91 per rentable square foot of Suite 204 per month (i.e., $2,446.71);
provided, however, Tenant is entitled to a pro rata portion of one month's free
rent for each applicable Suite, which amount shall be determined by multiplying
one month of the applicable Base Monthly Rental by a fraction, the numerator of
which is the number of months that applicable Suite shall be leased in the
initial term and the denominator of which shall be eighty-four (84) months, all
as set forth in Article 1.3(2) of the Lease.

               4. Base Year/Tenant's Share. The Base Year with respect to Suites
300 and 204 shall be the calendar year 1997. Tenant's Share with respect to
Suite 300 shall be 0.83% and with respect to Suite 204 shall be 0.96%.

                                      -2-
<PAGE>   21

               5. Tenant Improvements. The construction of the Base Building
Work and the Tenant Improvements for each Suite shall be governed by the terms
and conditions of the Work Letter attached hereto as Exhibit "B". Landlord shall
deliver possession of: (a) Suite 300 to Tenant no later than January 24, 1997;
and (b) Suite 204 to Tenant no later than February 28, 1997; provided; however,
if Landlord fails to deliver possession of the particular Suite by the
applicable date provided above, because of a "Landlord Delay"(as defined in
Article 11(b) of Exhibit "B" attached hereto), and such failure to deliver
possession of the applicable Suite is not the result of any "Force Majeure
Delay" (as defined in Article 11(a) of Exhibit "B" attached hereto), any delay
caused by the failure of any existing tenant to vacate the Suite, and/or any
action or inaction on the part of Tenant, then Tenant shall be entitled to one
(1) additional day of abatement of Base Monthly Rental for the applicable Suite
for each such day of Landlord Delay in delivery of possession of (i) Suite 300
beyond January 24, 1997, or (ii) Suite 204 beyond February 28, 1997, as
applicable. Delivery of possession of the applicable Suite shall be deemed to
have occurred when the conditions set forth in Article 1.6(b) of the Lease have
been satisfied with respect thereto. (For purposes of this Paragraph A.5,
references in Article 1.6(b) of the Lease to the "Work Letter" shall refer to
the Work Letter attached hereto as Exhibit "B".) The provisions of the last
sentence of Article 1.6(a) the Original Lease is not applicable to Suite 204 or
Suite 300.

               6. The Demised Premises. Upon the 300 Commencement Date, Suite
300 shall be deemed to be a part of the Demised Premises and upon the 204
Commencement Date, Suite 204 shall be deemed to be a part of the Demised
Premises, and except as otherwise provided in this Third Amendment or in the
Lease, shall be leased upon, and subject to all of the terms, covenants, and
conditions of the Lease.

        B. Reduction Space.

               1. Termination of Reduction Space. Landlord and Tenant hereby
acknowledge and agree that the Lease, as modified by this Third Amendment, with
respect to the Reduction Space shall be terminated and be of no further force or
effect as of midnight one (1) week following the execution of this Third
Amendment to Lease (the "Reduction Space Termination Date"). On or prior to the
Reduction Space Termination Date, Tenant shall surrender exclusive possession of
the Reduction Space to Landlord in accordance with the surrender provisions of
the Lease.

               2. Reduction of Demised Premises. Effective as of the Reduction
Space Termination Date, the Demised Premises leased by Tenant from Landlord
under the Lease, as modified by this Third Amendment, shall no longer include
the Reduction Space.

               3. Monthly Rental Amount. Due to the reduction of the Reduction
Space, effective as of the Reduction Space Termination Date, the Base Monthly
Rent for Suite 302 which comprises a portion of the Demised Premises shall be
reduced by $200.60 per month from $12,129.50 (i.e., 7,135 rentable square feet
times $1.70 per rentable square foot)(the rentable square feet for Suite 302 is
per Exhibit A-1 of the Original Lease) to $11,928.90 (i.e., 7,017 rentable
square feet times $1.70 per rentable square foot).

                                      -3-
<PAGE>   22

               4. Tenant's Share. Due to the reduction of the Reduction Space,
effective as of the Reduction Space Termination Date, Tenant's Share with
respect to Suite 302 of the Demised Premises shall be reduced to .05%.
Miscellaneous.

        C. Miscellaneous

               1. Brokers. Landlord agrees to pay Colliers Advisory Group, a
division of Colliers Parish International, Inc. ("Broker") a commission on Suite
300 and Suite 204 pursuant to a separate agreement between Landlord and Broker.
Tenant represents and warrants to Landlord that Tenant has not had any
discussions or negotiations or otherwise dealt with any other real estate broker
or agent other than Broker in connection with this Third Amendment or the
leasing of Suite 200 or Suite 304. Tenant shall indemnify, defend, protect and
hold Landlord harmless from and against any and all costs, expenses, claims and
liabilities (including costs of suit and reasonable attorneys' fees) for any
compensation, commission or fees claimed by any other real estate broker or
agent except Damner Pike & Company and Seagate Properties, Inc. in connection
with this Third Amendment or its negotiation by reason of any act of Tenant.

               2. Payments and Notices to Landlord. Landlord's notice and
payment addresses set forth in the Lease are hereby revised such that all
Monthly Base Rental and additional rent and any notices desired or required to
be delivered to Landlord pursuant to the provisions of the Lease, as amended
hereby, shall be addressed as follows, or to such other address or addresses as
Landlord may specify by notice to Tenant (and otherwise forwarded pursuant to
the remaining terms and provisions of the Lease):

                    c/o Lincoln Property Company
                    1100 Larkspur Landing Circle, Suite 155
                    Larkspur, California 94939
                    Attention: Property Manager

                    With a copy of notices (only) to:

                    c/o Lincoln Property Company
                    101 Lincoln Center Drive
                    Foster City, California 94404
                    Attention: Asset Manager

               3) Parking. Pursuant to Section 1(L) "Number of Reserved Parking
Spaces," Tenant shall be entitled to thirty-seven (37) reserved parking spaces,
per parking plan attached hereto as Exhibit "D" or other mutually agreeable
parking plan.

               4) Suite 310 Access. By execution of this Third Amendment,
Landlord and Tenant acknowledge that one interior door within Suite 300 is a
secondary access door to the adjacent suite, Suite 310. For reference, said
access door is identified as such on Exhibit "A-1" attached hereto. Upon
Landlord's delivery of Suite 300 to Tenant, Landlord shall install a one-way
lock on said access door at Landlord's sole cost and expense. Said lock shall
prevent the access to Suite 300 from Suite 310. Tenant hereby agrees to allow
access through this door

                                      -4-
<PAGE>   23

during normal business hours from time to time by the adjacent tenant in Suite
310, provided the adjacent tenant, "CompuServe", gives 24-hour notice.

               5. Defined Terms. Except as amended by this Third Amendment, all
of the capitalized terms used herein but not herein defined shall have the same
meanings ascribed to them in the Lease.

               6. Status of Lease. Except as amended by this Third Amendment,
the Lease remains unchanged, and as amended, all of the terms, covenants and
conditions of the Lease remain in full force and effect.

                                      -5-
<PAGE>   24

               IN WITNESS WHEREOF, the parties hereto have executed this Third
Amendment as of the day and year first above written.

"LANDLORD"                         LINCOLN PROPERTY COMPANY M.S., INC.,
                                   as Manager for:

                                   WHLW Real Estate Limited Partnership,
                                   a Delaware Limited Partnership

                                   By: /s/ D. ALLEN PALMER
                                      ------------------------------------------
                                   Name: D. Allen Palmer
                                        ----------------------------------------
                                   Title: Vice President
                                         ---------------------------------------

"TENANT"                           AUTODESK, INC.,
                                   a California corporation

                                   By: /s/ STEVE McMAHON
                                      ------------------------------------------
                                   Name:  Steve McMahon
                                        ----------------------------------------
                                   Title: Vice President
                                         ---------------------------------------

                                      -6-
<PAGE>   25

                        [EXHIBITS INTENTIONALLY DELETED]

<PAGE>   26

                            SECOND AMENDMENT TO LEASE

THIS SECOND AMENDMENT TO LEASE (the "Second Amendment") is made and entered into
as of the 22nd day of December, 1995, by and between Connecticut General Life
Insurance Company, a Connecticut corporation ("Landlord") and Autodesk, Inc., a
California corporation ("Tenant").

                                   WITNESSETH

        WHEREAS, Tenant and Landlord entered into that certain Office Lease
dated August 2, 1993 (the "Lease"), for certain premises specified in the Basic
Lease Information attached to the Lease, in the Marin Executive Center (the
"Building") located at 4000 Civic Center Drive in the City of San Rafael, County
of Marin, State of California; and

        WHEREAS, Tenant and Landlord entered into that certain First Amendment
to Lease Agreement dated February 14, 1994 (the "First Amendment"), whereby
certain Expansion Space was incorporated within the Demised Premises and the
measurements of the Initial Premises were revised; and

        WHEREAS, Tenant desires to incorporate additional Expansion Space within
the Demised Premises in accordance with the terms of the Lease; and

        WHEREAS, Landlord and Tenant desire to further amend and modify certain
provisions of the Lease as more particularly described below in order to
accommodate the addition of the Expansion Space;

        NOW, THEREFORE, in consideration of the mutual benefits accruing to the
parties hereto and for other valuable consideration, the receipt and sufficiency
of which is hereby acknowledged, it is hereby agreed that the Lease shall be
amended in the following respects:

        1. Exercise of Expansion Option. Pursuant to Article 1.3 of the Lease,
Tenant does hereby exercise its Expansion Option on 20,349 rentable square feet
of space located on the fourth floor and consisting of the entire fourth floor
of the Building ("Suite 400"), as more particularly described on the attached
Exhibit A which is hereby incorporated into this Second Amendment. The parties
shall confirm measurement of the rentable square footage of Suite 400 in
accordance with the terms of Article 1.2 of the Lease.

        2. Term. In accordance with Article 1.3(2) of the Lease, the
Commencement Date shall be sixty (60) days following the date that Landlord
delivers possession (as that term is defined in Paragraph 5 hereof) of Suite 400
to the Tenant. In accordance with Tenant's election, the term for Suite 400
shall be coterminous with

<PAGE>   27

the term of the Lease and thus shall expire on December 22, 2000, unless
extended in accordance with the terms of the Lease (the "Expiration Date").

        3. Rent. Beginning on the Commencement Date, Tenant shall pay Base
Monthly Rental for Suite 400 in an amount equal to $1.84 per rentable square
foot of Suite 400 per month (i.e., $37,442); provided, however, Tenant is
entitled to a pro rata portion of one month's free rent determined by
multiplying one month of Base Monthly Rental for Suite 400 ($37,442) by a
fraction, the numerator of which is the number of months that Suite 400 shall be
leased in the initial term and the denominator of which shall be eighty-four
(84) months, all as set forth in Article 1.3(2) of the Lease.

        4. Base Year/Tenant's Share. The Base Year with respect to Suite 400
shall be the calendar year 1996. Tenant's Share with respect to Suite 400 shall
be 15.26%.

        5. Tenant Improvements. The construction of the Base Building Work and
the Tenant Improvements for Suite 400 shall be governed by the terms and
conditions of the Work Letter attached hereto as Exhibit B. Landlord shall
deliver possession of Suite 400 to Tenant no later than September 15, 1996;
provided, however, if Landlord fails to deliver possession of Suite 400 by
September 15, 1996, Tenant shall be entitled to one additional day abatement of
Base Monthly Rental for Suite 400 for each day delay in delivery of possession
of Suite 400 beyond September 15, 1996. Delivery of possession of Suite 400
shall be deemed to have occurred when the conditions set forth in Article 1.6(b)
of the Lease have been satisfied with respect to Suite 400. (For purposes of
this Paragraph 5, references in Article 1.6(b) of the Lease to the "Work Letter"
shall refer to the Work Letter attached hereto as Exhibit B.)

        6. The Demised Premises. Upon the Commencement Date for Suite 400, Suite
400 shall be deemed to be a part of the Demised Premises and, except as
otherwise provided in this Second Amendment or in the Lease, shall be leased
upon and subject to all of the terms, covenants and conditions of the Lease.

        7. Defined Terms. Except as amended by this Second Amendment and
the First Amendment, all of the capitalized terms used herein but not herein
defined shall have the same meanings ascribed to them in the Lease.

                                       2
<PAGE>   28

        8. Status of LEASE. Except as amended by this Second Amendment and the
First Amendment, the Lease remains unchanged, and as amended, all of the terms,
covenants and conditions of the Lease remain in full force and effect.

IN WITNESS WHEREOF, the parties hereto have executed this Second Amendment as of
the day and year first above written.

LANDLORD:                                   TENANT:

Connecticut General Life                    Autodesk, Inc., a
Insurance Company,                          California corporation
a Connecticut corporation

BY: CIGNA Investments, Inc.                 By: /s/ CAROL BARTZ
   -------------------------------             ---------------------------------
By: /s/ JEAN M. ANDERSON                    Its: President & CEO
   -------------------------------              --------------------------------
Its: Vice President
    ------------------------------

                                       3
<PAGE>   29

                        [EXHIBITS INTENTIONALLY OMITTED]

<PAGE>   30

                            FIRST AMENDMENT TO LEASE

THIS FIRST AMENDMENT TO LEASE (the "First Amendment") is made and entered into
as of the 2/14, 1994, by and between Connecticut General Life Insurance Company,
a Delaware Corporation ("Landlord") and Autodesk, Inc. a California corporation
("Tenant").

                                   WITNESSETH

WHEREAS, Tenant and Landlord entered into that certain lease agreement dated
August 2, 1993, (the "Lease") for certain premises (the "Premises"), specified
in the Basic Lease Information attached to the Lease, in the Marin Executive
Center (the "Building") located at 4000 Civic Center Drive in the City of San
Rafael, County of Marin, State of California (the "Real Property"); and

WHEREAS, Tenant desires to incorporate certain Expansion Space within the
Demised Premises and to revise the measurements of Suites 202, 208, 301, 302,
305 and 306 based on the final design and layout of the tenant improvements; and

WHEREAS, Landlord and Tenant desire to agree to amend and modify certain
provisions of the Lease as more particularly described below;

NOW, THEREFORE, in consideration of the mutual benefits accruing to the parties
hereto and for other valuable consideration, the receipt and sufficiency of
which is hereby acknowledged, it is hereby agreed that the Lease shall be
amended in the following respects:

        1. Section II - General Lease Provisions, Sub-paragraph 1.1 entitled
        "Definitions" is hereby amended and revised by deleting the

<PAGE>   31

AUTODESK FIRST AMENDMENT                                                  Page 2

        sub-section in its entirety and inserting in its place the following:

        "1.1 Definitions.

        (a) The term "Initial Premises" shall mean approximately 77,105 rentable
        square feet of space in the Building comprised of the following:

               Suite  100          = 36,203 rentable square feet
               Suites 202 & 208    = 12,039 rentable square feet
               Suite  212          = 5,118 rentable square feet
               Suites 301 & 302 &
                      305 & 306    = 23,745 rentable square feet
               -------------------------------------------------
               Total               = 77,105 rentable square feet

        Floor plans showing each of the suites comprising the Initial Premises
        are attached hereto as "Amended Exhibit A-1."

        2. The attachments to the Lease labeled "Exhibit A-1" shall be deleted
        and replaced with the attachments to this First Amendment labeled
        'Amended Exhibit A-1".

        3. Pursuant to the Lease, Paragraph 1.3 entitled Expansion Space, Tenant
        does hereby exercise its Expansion Option on 4,042 rentable square feet
        of space located on the third floor, west wing, (referred to herein as
        "Suite 310") as more particularly detailed on the attached Exhibit A-2,
        which Exhibit A-2, by this reference, is hereby incorporated into the
        Lease. In accordance with Paragraph 1.3(2) the Commencement Date shall
        be 45 days from the date that the space is delivered to the Tenant in a
        condition as described in the Work Letter. In addition, the 45 day
        period shall not commence until Landlord has completed the installation
        of the main HVAC trunk duct loop

<PAGE>   32

AUTODESK FIRST AMENDMENT                                                  Page 3

        within Suite 310. The Base Monthly Rent on Suite 310 shall commence one
        month from the Commencement Date, at the Base Monthly Rental rate
        specified in Section 1.10 of the Lease. The term for Suite 310 shall be
        coterminous with the term of the Lease.

        4. Pursuant to the Lease, Paragraph 1.3 entitled Expansion Space, Tenant
        does hereby exercise its Expansion Option on 6,780 rentable square feet
        of space located on the third floor, west wing, (referred to herein as
        "Suite 304") as more particularly detailed on the attached Exhibit A-2.
        Landlord anticipates that it will deliver Suite 304, in a condition as
        described in the Work Letter and with the main HVAC trunk duct loop
        installed within Suite 304, prior to March 15, 1994. Landlord and Tenant
        hereby agree that at any time prior to March 15, 1994, with regard to
        Suite 304 only, Landlord may give Tenant ten (10) business days notice
        that Landlord has completed its improvements in accordance with the Work
        Letter (including the installation of the main HVAC trunk duct loop). At
        the expiration of Landlord's ten (10) day notice period, Tenant shall
        have forty-five (45) days as a tenant improvement period. If the
        Landlord delivers Suite 304 at the same time as Suite 310, resulting in
        a total of 10,822 rentable square feet being delivered at one time, then
        the forty-five (45) day Tenant Improvement period referred to above,
        shall be extended to sixty (60) days. The Base Monthly Rent for Suite
        304 shall commence one month from the Commencement Date, at the Base
        Monthly Rental rate specified in Paragraph 1.10 of the Lease. The term
        for Suite 304 shall be coterminous with the term of the Lease.

        5. Notwithstanding Paragraph 1.3 of the Lease, Tenant does hereby waive
        its Expansion Option on Suite 309 for the period commencing with the
        execution of this First Amendment and ending on June 30, 1995 at which
        time Suite 309 will be

<PAGE>   33

AUTODESK FIRST AMENDMENT                                                  Page 4

        considered as Expansion Space subject to any prior expansion rights of
        PacifiCare Inc, and the rights and restrictions contained in Paragraph
        1.3 of the Lease. Prior to June 30, 1995 Landlord shall have the right,
        but not the obligation, to lease Suite 309 provided the lease terminates
        effective June 30, 1995, unless Landlord leases the space to an existing
        Building tenant under an existing expansion option contained in that
        tenant's lease. After June 30, 1995, Tenant shall have the right, but
        not the obligation, to exercise Tenant's Expansion Option on Suite 309
        all in accordance with the Lease provisions. Nothing contained herein
        shall preclude Landlord from offering Suite 309 to Tenant prior to June
        30, 1995 as Expansion Space under Tenants Expansion Option.

        6. In order to accommodate Tenant with Tenant's Expansion Option on
        Suite 310, Landlord hereby agrees to move the Building management office
        to the location indicated on Amended Exhibit A. Tenant does hereby agree
        to reimburse Landlord for all reasonable costs associated with
        construction of the replacement Building management office including,
        but not limited to, architectural and engineering costs, construction
        costs, all costs associated with moving data transmission lines, phone
        lines, furniture, files and other such items. Landlord shall have the
        unlimited right to use contractors and suppliers of Landlord's own
        choice. Tenant shall be entitled to review all contracts and expenses
        associated with the construction of the tenant improvements within the
        new management office. Tenant's obligation to reimburse Landlord under
        this Paragraph 6 shall be limited to a maximum expenditure of Ten
        Thousand Dollars ($10,000.00).

        7. Paragraph 1.3(2), entitled "Expansion Space", is hereby amended and
        revised by deleting the first sentence completely and in its place
        inserting the following sentence:

<PAGE>   34

AUTODESK FIRST AMENDMENT                                                  Page 5

        "(2) Landlord shall deliver all Expansion Space to Tenant in the same
        condition as the Demised Premises referred to in the work Letter
        attached hereto at least the following number of days prior to the dates
        set forth as the Commencement Dates for such space based upon the
        rentable square feet of the Expansion Space: forty-five (45) days for
        10,000 square feet or less, sixty (60) days for more than 10,000 square
        feet but less than 50,000 square feet, and ninety (90) days for more
        than 50,000 square feet; provided, however, in the case of a un-natural
        termination or other termination of a lease (as opposed to the failure
        of a tenant to exercise its right to renew or expand), the foregoing
        time periods shall be extended by sixty (60) days."

        Except as modified above, all the terms and conditions of Paragraph
        1.3(2) shall remain unchanged.

        8. Except as amended by this First Amendment, all of the terms used
        herein that are defined in the Lease shall have the same meanings as
        therein defined. Except as amended by this First amendment, all of the
        terms, covenants and conditions of the Lease shall remain in full force
        and affect.

        9. Landlord and Tenant hereby agree and stipulate that the Expiration
        Date, as defined in Paragraph 1.6 of the Lease, for the Initial Premises
        consisting of Suites 100, 202, 208, 212, 301, 302, 305 and 306 shall be
        December 22, 2000. In addition, Landlord and Tenant hereby agree and
        stipulate that the Expiration Date for Suites 304 and 310 shall also be
        December 22, 2000. The Expiration Date for any Expansion Space on which
        Tenant exercises its Expansion Option after the date of this First
        Amendment shall be as prescribed in the Lease.

<PAGE>   35

AUTODESK FIRST AMENDMENT                                                  Page 6

IN WITNESS WHEREOF, the parties hereto have executed this First Amendment as of
the day and year first above written.

LANDLORD:                               TENANT:

Connecticut General Life                Autodesk, Inc. a
Insurance Company, a                    Delaware corporation
Delaware corporation

By: CIGNA Investments, Inc.

By: /s/ STEPHEN J. OLSTEIN              By: /s/ ERIC HERR
   -----------------------------           -------------------------------------
Its: Managing Director                  Its:   Chief Financial Officer
    ----------------------------            ------------------------------------

<PAGE>   36

                        [EXHIBITS INTENTIONALLY OMITTED]

<PAGE>   37

                             MARIN EXECUTIVE CENTER

                                  OFFICE LEASE

             Landlord:  Connecticut General Life Insurance Company

             Tenant:    Autodesk, Inc.

<PAGE>   38

                             MARIN EXECUTIVE CENTER
                                  OFFICE LEASE

                               TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                      Page
                                                                      ----
<S>  <C>  <C>                                                          <C>
SECTION I -- LEASE TERMS .............................................  i

SECTION II - GENERAL LEASE PROVISIONS ................................  1
     1.   DEMISED PREMISES, TERM, RENT ...............................  1
          1.1  Definitions ...........................................  1
          1.2  Demised Premises, Square Footage ......................  1
          1.3  Expansion Space .......................................  2
          1.4  Use of Common Areas ...................................  4
          1.5  Reserved Parking ......................................  4
          1.6  Term; Possession; Contingencies .......................  5
               (a)  Term .............................................  5
               (b)  Possession .......................................  5
               (c)  Contingent Premises ..............................  6
          1.7  Late Delivery .........................................  7
          1.8  Option to Extend ......................................  7
               (a)  Notice of Exercise ...............................  8
               (b)  Terms ............................................  8
               (c)  Fair Market Rent .................................  9
               (d)  Arbitration Fees .................................  9
               (e)  Late Rent Determination .......................... 10
               (f)  No Default ....................................... 10
          1.9  Right to Terminate .................................... 10
          1.10 Base Monthly Rent ..................................... 10
          1.11 Payment Dates ......................................... 10
          1.12 Interest; Late Charges ................................ 11
     2.   OCCUPANCY .................................................. 12
          2.1  Purpose ............................................... 12
          2.2  Common Areas .......................................... 12
          2.3  Right to Change Common Areas .......................... 12
          2.4  Common Area Easements ................................. 12
          2.5  Use of Parking Spaces ................................. 13
     3.   ASSIGNMENT, MORTGAGE, SUBLETTING ........................... 13
          3.1  Consent Required ...................................... 13
          3.2  Grounds for Denying Consent ........................... 14
          3.3  Further Conditions to Assignment ...................... 14
          3.4  Right to Share Rent ................................... 15
     4.   ALTERATIONS ................................................ 15
          4.1  Alterations ........................................... 15
     5.   REPAIRS .................................................... 17
          5.1  Tenant Repairs ........................................ 17
          5.2  Landlord Repairs ...................................... 17
          5.3  Tenant's Failure to Repair ............................ 18
     6.   REQUIREMENTS OF LAW, INSURANCE ............................. 18
          6.1  Requirements of Law ................................... 18
          6.2  Insurance Underwriters ................................ 19
          6.3  ADA Requirements ...................................... 20
     7.   SUBORDINATION, MORTGAGES, NONDISTURBANCE ................... 20
</TABLE>

<PAGE>   39

<TABLE>
<S>  <C>                                                                     <C>
20.  NO REPRESENTATIONS BY LANDLORD........................................   38
     20.1   No Representations.............................................   38
21.  END OF TERM...........................................................   38
     21.1   Surrender......................................................   38
22.  QUIET POSSESSION......................................................   39
     22.1   Quiet Possession...............................................   39
23.  TERMINATION, NO WAIVER, NO ORAL CHANGE                                   39
     23.1   Termination, No Waiver, No Oral Change.........................   39
24.  WAIVER OF TRIAL BY JURY [INTENTIONALLY DELETED].......................   40
25.  INABILITY TO PERFORM..................................................   40
     25.1   Inability to Perform...........................................   40
26.  BILLS AND NOTICES.....................................................   41
     26.1   Bills and Notices..............................................   41
27.  ADDITIONAL CHARGES FOR INCREASED OPERATING EXPENSES AND TAXES.........   41
     27.1   Definitions....................................................   41
     27.2   Gross Up For Less Than 95% Occupancy...........................   47
     27.3   Change of Policy...............................................   47
     27.4   Allowances.....................................................   47
     27.5   Tenant Payments................................................   47
     27.6   Proration of Computation Year..................................   48
     27.7   Books and Records..............................................   49
28.  TAX ON TENANT'S PERSONAL PROPERTY.....................................   49
     28.1   Tax on Tenant's Personal Property..............................   49
29.  FOOD, BEVERAGES AND ODORS.............................................   50
     29.1   Food, Beverages and Odors......................................   50
30.  SECURITY DEPOSIT......................................................   50
     30.1   Security Deposit...............................................   50
31.  ARTICLE HEADINGS......................................................   50
     31.1   Article Headings...............................................   50
32.  DEFINITIONS...........................................................   50
     32.1   Definitions....................................................   50
33.  LANDLORD'S APPROVAL...................................................   51
     33.1   Landlord's Approval............................................   51
34.  BROKERAGE.............................................................   51
     34.1   Brokerage......................................................   51
35.  BINDING EFFECT........................................................   51
     35.1   Binding Effect.................................................   51
36.  MISCELLANEOUS.........................................................   51
     36.1   Offer to Lease.................................................   51
     36.2   Contractors....................................................   51
     36.3   Joint and Several Liability....................................   52
     36.4   California Law.................................................   52
     36.5   Partial Invalidity.............................................   52
     36.6   Security Patrol................................................   52
     36.7   Basement Storage...............................................   52
     36.8   Time of Essence................................................   53
     36.9   No Recordation.................................................   53
     36.10  Name Change....................................................   53
     36.11  Estoppel Certificates..........................................   53
     36.12  Limited Liability..............................................   53
     36.13  Common Area Rights.............................................   54
     36.14  Governmental Regulation........................................   54
</TABLE>

<PAGE>   40
<TABLE>
<S>  <C>                                                                     <C>
     7.1    Subordination..................................................   20
     7.2    Mortgages......................................................   20
     7.3    Further Assurances.............................................   20
     7.4    Nondisturbance.................................................   21
8.   RULES AND REGULATIONS.................................................   21
     8.1    Rules and Regulations..........................................   21
9.   LIABILITY AND INDEMNIFICATION.........................................   21
     9.1    Tenant Indemnification.........................................   22
     9.2    Landlord Indemnification.......................................   22
     9.3    Limitation of Landlord's Responsibility........................   22
     9.4    Tenant's Payments..............................................   23
10.  DAMAGE OR DESTRUCTION.................................................   23
     10.1   Damage of Destruction..........................................   23
     10.2   No Obligation to Rebuild Beyond Insurance......................   24
     10.3   Tenant Waivers.................................................   24
     10.4   Waiver of Subrogation..........................................   24
     10.5   Loss of Waiver.................................................   25
11.  EMINENT DOMAIN........................................................   25
     11.1   Eminent Domain.................................................   25
     11.2   Tenant's Award.................................................   25
     11.3   Partial Taking.................................................   26
     11.4   Restoration....................................................   26
     11.5   Temporary Taking...............................................   26
     11.6   Landlord Settlement............................................   26
12.  SERVICES..............................................................   27
     12.1   Landlord's Services............................................   27
     12.2   Notice of Shut-Downs...........................................   29
     12.3   Interruption of Services.......................................   29
     12.4   HVAC Improvements..............................................   29
13.  ACCESS TO DEMISED PREMISES............................................   29
     13.1   Access to Demised Premises.....................................   30
14.  INSURANCE.............................................................   30
     14.1   Tenant's Insurance.............................................   30
     14.2   Policy Requirements............................................   31
     14.3   Evidence of Insurance..........................................   31
     14.4   Landlord's Insurance...........................................   31
     14.5   Waiver of Subrogation..........................................   32
15.  CERTIFICATES OF OCCUPANCY.............................................   32
     15.1   Certificates of Occupancy......................................   32
16.  SECURITY..............................................................   33
     16.1   Security........................................................  33
17.  BANKRUPTCY.............................................................  33
     17.1   Prior to Term...................................................  33
     17.2   During Term.....................................................  33
     17.3   Remedies........................................................  34
18.  DEFAULT................................................................  34
     18.1   Tenant's Breach.................................................  34
     18.2   Termination Notice..............................................  34
     18.3   Option to Continue Lease........................................  35
     18.4   Damages.........................................................  35
     18.5   Landlord's Right to Perform Work................................  36
19.  LANDLORD'S DEFAULT.....................................................  37
     19.1   Landlord's Default..............................................  37
</TABLE>
<PAGE>   41
<TABLE>
<S>                                                                    <C>
    36.15 Due Authorization ...............................            54
    36.16 Dispute Resolution ..............................            54
    36.17 Exhibits ........................................            54
39. SIGNAGE ...............................................            55
    37.1 Signage ..........................................            55
38. HAZARDOUS MATERIALS ...................................            55
    38.1 Tenant Compliance ................................            55
    38.2 Landlord's Representations .......................            56
</TABLE>

EXHIBITS

A-1 Initial Premises
A-2 Contingent Premises
A-3 Penthouse
B   Site
C   Reserved Parking Spaces
D   Work Letter Agreement
E   Subordination, Non-Disturbance and Attornment
F   Rules and Regulations
G   Janitorial Specifications
H   HVAC and Noise Specifications
I   Commissions

<PAGE>   42

                             KARIN EXECUTIVE CENTER
                                  OFFICE LEASE

        In consideration of the rents and covenants hereinafter set forth, the
Landlord named in Article B of Section I hereby leases to the Tenant named in
Article C of Section I, and Tenant hereby leases from Landlord, the Demised
Premises described in Article F of Section I of this Marin Executive Center
Office Lease (the "Lease") upon the terms, covenants, provisions and agreements
hereinafter specified.

                            SECTION I -- LEASE TERMS

        The lease terms provided in this Section I (the "Lease Terms") is
subject to the main body of the Lease in general and those paragraphs noted in
parentheses in particular.

A.      Date of Lease: August 2, 1993

8.      Landlord: Connecticut General Life Insurance Company

C.      Tenant: Autodesk, Inc.

D.      Trade Name (if any): N/A

E.      Guarantor: N/A

F.      Demised Premises
        (Section II, Article 1): Initial Premises: Suites 100, 202, 208, 212,
                                 301, 302, 305 and 306
                                 Contingent Premises: Suites 200 and 204

G.      Lease Term
        (Section II, Article. l): As set forth in Section II, Article 1.

        Commencement Date: As set forth in Section II, Article 1

        Expiration Date: As set forth in Section II, Article 1

H.      Base Monthly Rent
        (Section II, Article 1): As set forth in Section II, Article 1

        Monthly Installments: As set forth in Section II, Article 1

        Periodic Rent Increase Date: N/A

                                      -i-
<PAGE>   43

I.      Use of Premises
        (Section II, Article 2): General office and other ancillary uses related
                                 thereto consistent with the character of the
                                 Building

J.      Address for Notice to Landlord and Tenant (Section II, Article 26):

        Landlord:              c/o CIGNA-Investments, Inc.
                               900 Cottage Grove Road, S311
                               Bloomfield, Connecticut 06002
                               Attn: Asset Management Department

                               With copies to:

                               c/o CIGNA Investments, Inc.
                               900 Cottage Grove Road, S311
                               Bloomfield, Connecticut 06002
                               Attn: Investments Legal Department

                                      and

                               c/o Seagate Properties, Inc.
                               4000 Civic Center Drive
                               San Rafael, California 94903

        Tenant:                Autodesk, Inc.
                               4000 Civic Center Drive
                               San Rafael, California 94903
                               Attn: Director of Corporate Real Estate

                               With a copy to:

                               Autodesk, Inc.
                               4000 Civic Center Drive
                               San Rafael, California 94903
                               Attn: General Counsel

K.      Base Year: As set forth in Section II, Article 27

L.      Number of Reserved Parking Spaces
        (Section II, Article 1): One per 3,000 square feet of Rentable Area from
                                 time to time constituting a portion of the
                                 Demised Premises

M.      Tenant's Share of Excess Taxes, Expenses and Operating Costs
        (Section II, Article 27): As set forth in Section II, Article 27

        Rentable Area of the Building: 127,183

                                      -ii-
<PAGE>   44

        Rentable Area of Demised Premises: As set forth in Section II, Article 1

N.      Security Deposit (Section II, Article 30): None

O.      Broker(s) (Section II, Article 34):

        Landlord:             Seagate Properties, Inc.
                              650 California Street, Suite 650
                              San Francisco, California 94108

        Tenant:               Colliers Advisory Group
                              1960 The Alameda, Suite 100
                              San Jose, California 95126

                                     -iii-
<PAGE>   45

                     SECTION II - GENERAL LEASE PROVISIONS

1.      DEMISED PREMISES, TERM, RENT

        1.1     Definitions.

                (a) The term "Initial Premises" shall mean approximately 76,598
rentable square feet of space in the Building comprised of the following:

                Suite 100 = 36,203 rentable square feet
                Suite 202 =    836 rentable square feet
                Suite 208 = 10,610 rentable square feet
                Suite 212 =  5,118 rentable square feet
                Suite 301 =    602 rentable square feet
                Suite 302 =  7,135 rentable square feet
                Suite 305 =  8,430 rentable square feet
                Suite 306 =  7,664 rentable square feet
                ---------------------------------------
                Total -     76,598 rentable square feet

Floor plans showing each of the suites comprising the initial Premises are
attached hereto as Exhibit A-1.

                (b) The term "Contingent Premises" shall mean approximately
6,483 rentable square feet of space in the Building comprised of the following:

                Suite 200 = 5,087 rentable square feet
                Suite 204 = 1,396 rentable square feet
                --------------------------------------
                Total -     6,483 rentable square feet

Floor plans showing each of the suites comprising the Contingent Premises are
attached hereto as Exhibit A-2.

                (c) The term "Demised Premises" shall mean the Initial Premises
together with so much of the Contingent Premises as shall at any time have been
delivered by Landlord to Tenant under the terms of this Lease and so much of the
Expansion Space from time to time then included in the Demised Premises
pursuant to Article 1.3.

                (d) The term "Building" shall mean the building known as the
Marin Executive Center, 4000 Civic Center Drive, San Rafael, California.

                (e) The term "Site" shall mean the real property and
improvements shown on Exhibit-B.

                                      -1-
<PAGE>   46

        1.2 Demised Premises, Square Footage. Upon and subject to the terms,
covenants and conditions hereinafter set forth, Landlord hereby leases to Tenant
and Tenant hereby leases from Landlord the Demised Premises. Tenant, at Tenant's
sole cost and expense, shall have the right to verify the square footage of the
Demised Premises by field measurements, such measurements to be completed and
performed in accordance with the American National Standard Method of Measuring
Floor Areas in Office Buildings of the Building Owners and Managers Association
International (ANSI Z65.1-1989). In the event that such field measurements and
computation of square footage establish that the square footage of any
portion(s) of the Demised Premises differs from the square footage of such
portions(s) of the Demised Premises specified above, the actual square footage
of such portions(s) the Demised Premises shall be reconciled and agreed upon by
Landlord and Tenant, shall be confirmed in writing by the parties and the Base
Monthly Rent (as defined below) payable under this Lease, as well as (i)
Tenant's Share (as defined below), (ii) the Tenant Improvement Allowance (as
defined in the Work Letter), and (iii) the Additional Allowance (as defined in
the Work Letter), shall be appropriately adjusted. With regard to any portion of
the Building that is part of the Demised Premises or that becomes part of the
Demised Premises as a result of the exercise by Tenant of any expansion options
set forth below, the parties agree that the rentable square footage of each such
portion of the building shall be determined as follows: (i) in the case of any
full floor occupied by Tenant, the number of rentable square feet of such floor
shall equal the product of the usable square feet of such floor (determined as
specified above) multiplied by 101.058%; and (ii) in the case of a multi-tenant
floor in the Building, the number of rentable square feet within any portion of
the Demised Premises located on such multi-tenant floor shall be equal to the
product of the usable square feet within such portion of the Demised Premises on
that floor (determined as specified above) multiplied by 113.25%.

        1.3 Expansion Space. Provided there is no outstanding uncured default by
Tenant under this Lease, Tenant shall have the right to lease all additional
space in the Building other than the Demised Premises (the "Expansion Space")
(such right being herein called the "Expansion Option"), upon and subject to the
provisions of this Article.

                (1) In the event a tenant with a now existing right to renew or
expand fails to exercise its right to renew or expand within the time period for
such renewal or expansion, or in the event or any space in the Building becomes
available because of the natural expiration or other termination of a lease or
for any other reason, Landlord shall provide Tenant with written notice, within
five (5) business days of such failure to exercise a right or other event
causing such space to be available, as the case may be, specifying (i) the
estimated square footage, location and estimated dates that such space is
available for occupancy by Tenant, and

                                      -2-
<PAGE>   47

(ii) consistent with the time periods set forth in the following sentence, the
number of days within which Tenant is required to exercise its option. Tenant
shall exercise the Expansion Option within ten (10) business days of receipt of
such notice from Landlord in the case the failure of a tenant to exercise its
right to renew or expand, or within fifteen (15) business days in the case of
the natural expiration or other termination of a lease.

                (2) [Landlord shall deliver all Expansion Space to Tenant in the
same condition as the Demised Premises referred to in the Work Letter attached
hereto at least the following number of days prior to the dates set forth as the
Commencement Dates for such space based upon the rentable square feet of the
Expansion Space: forty-five (45) days for 10,000 square feet or less, sixty (60)
days for more than 10,000 square feet but less than 50,000 square feet, and
ninety (90) days for more than 50,000 square feet: provided, however, in the
case of natural termination or other termination of a lease (as opposed the
failure of a tenant to exercise its right to renew or expand), the foregoing
time periods shall be extended by sixty (60) days.] If the Commencement Date
for the particular Expansion Space is prior to the expiration of the
thirty-sixth month of the initial term of the Lease, then the term of the Lease
with respect to the Expansion Space shall, at the election of Tenant, be either
(i) coterminous with the term of the Lease, or (ii) for seventy-two (72) months;
and if the Commencement Date for the particular Expansion Space is after the
expiration of the thirty-sixth month of the initial term of the Lease, then the
Expansion Space shall be leased for a term of seventy-two (72) months. Upon the
Commencement Date for any Expansion Space, the Expansion Space shall be deemed
to be a part of the Demised Premises and, except as otherwise provided below,
shall be leased upon and subject to all of the terms, covenants and conditions
of the Lease, including the Base Monthly Rent, the Tenant Improvement Allowance,
and the Additional Allowance. For any Expansion Space leased on or after
September 1, 1994, the Base Monthly Rent for the particular Expansion Space
shall be fixed for the entire term of such Expansion Space at one rate, such
Base Monthly Rent rate to be determined in accordance with the following
schedule:

<TABLE>
<CAPTION>
                                                   Amount Per Rentable
       Commencement Date                          Square Foot Per Month
       -----------------                          ---------------------
<S>                                               <C>
September 1, 1994 - August 31, 1995                       $1.77
September 1, 1995 - August 31, 1996                        1.84
September 1, 1996 - August 31, 1997                        1.91
September 1, 1997 - August 31, 1998                        1.99
September 1, 1998 - August 31, 1999                        2.07
September 1, 1999 - August 31, 2000                        2.15
</TABLE>

For any Expansion Space which Tenant has the right to elect, and does so elect,
to have the term coterminous with the term of the

                                      -3-
<PAGE>   48

Initial Premises, the Tenant Improvement Allowance provided by Landlord shall be
pro rated as follows: multiply the tenant improvement allowance of $18.00 per
rentable square foot of the Expansion Space qualifying for this proration by a
fraction, the numerator of which is the number of months that the Expansion
space shall be leased in the initial term, and the denominator of which shall be
eighty-four (84) months. The Additional allowance of $1.00 per rentable square
foot shall likewise be prorated with respect to Expansion Space with a term
coterminous with the term of the Initial Premises. For all Expansion Space
Tenant shall be entitled to a pro rata portion of one month's free rent
determined by multiplying one month's rent for such Expansion Space by a
fraction, the numerator of which is the number of months that the expansion
space shall be leased in the initial term and the denominator of which shall be
eighty-four (84) months. Notwithstanding anything to the contrary contained
herein, Tenant shall have the right to exercise the Extension Option (as defined
below) with respect to all Expansion Space as if the Expansion Space were part
of the Demised Premises originally; provided, however, with respect to any
Expansion Space which Tenant elects to occupy for a term of seventy-two (72)
months, the Extension Option a term of five (5) years commencing at the
expiration of the term of such Expansion Space, and Tenant's rights to expand
shall be exercised on or before the date that is nine (9) months prior to such
Expiration Date. For all Expansion Space a new Base Year shall be established
which shall be the calendar year in which the Commencement Date falls if such
Commencement Date falls within the first six (6) months of the calendar year, or
the calendar year following the year in which the Commencement Date falls if
such Commencement Date falls in the final six (6) months of the calendar year.

        1.4 Use of Common Areas. Tenant shall have the right, for the benefit of
Tenant and its employees, suppliers, shippers, customers, invitees, to the
non-exclusive use of all areas and facilities outside the Demised Premises and
within the exterior boundary line of the Site, that are provided and designated
by Landlord from time to time for the general non-exclusive use of Landlord,
Tenant and other tenants of the Site and their respective employees, suppliers,
shippers, customers and invitees, including outdoor parking areas, parking
garages, loading, unloading areas, drives, walkways, roadways, trash areas,
landscaped areas, common entrances, lobby's, restrooms, elevators, stairways and
accessways, and the common pipes, conduits, wires and appurtenant equipment
serving the premises (herein called "Common Areas"). Notwithstanding the
foregoing, for so long as the "deli" operates in its current location, Landlord
hereby agrees to install and keep a screen in the main lobby of the Building
between the current deli and Tenant's main entrance. The cost of installing the
screen shall be split evenly between Landlord and Tenant; and both parties shall
approve the design and color.

                                      -4-
<PAGE>   49

        1.5 Reserved Parking. Tenant shall have the right for the benefit of
Tenant and its employees, customers and invitees, to the exclusive use of the
number of Reserved Parking Spaces specified in the Lease Terms on those portions
of the Common Areas that are most near the front entrance to the Building, as
generally shown on Exhibit C attached hereto. Landlord shall make 416 parking
spaces on the Site available to Tenant on a "first come, first served" basis
with the other tenants of the Building.

        1.6 Term; Possession; Contingencies.

                (a) Term. The term of this Lease with respect to the Initial
Premises shall commence on the date ("Commencement Date") that is the earlier
of: (i) one-hundred and five (105) days from the date that Landlord delivers
possession (as defined in Article 1.6(b)) of the Initial Premises to Tenant, or
(ii) the date of occupancy by Tenant for business purposes; and the term of this
Lease with respect to each of the suites comprising the Contingent Premises
shall commence on the date that is the earlier of: (i) one hundred and five
(105) days from the date that Landlord delivers possession (as defined in
Article 1.6(b)) of such suite to Tenant, or (ii) the date of occupancy by Tenant
for business purposes. Unless sooner terminated as hereinafter provided, the
term of this Lease shall expire on the date that is eighty-five (85) months
from the Commencement Date for the Initial Premises (the "Expiration Date").
Notwithstanding the foregoing, Landlord and Tenant acknowledge that Landlord may
deliver possession of Suites 301 and/or 305 to Tenant on a later date than
Landlord delivers possession of the balance of the Initial Premises to Tenant;
and in such event, the term of this Lease with respect to Suites 301 and 305
shall commence on the date that is one hundred and five (105) days from the date
that Landlord delivers possession (as specified below) of the respective suites
to Tenant, but shall nevertheless terminate on the Expiration Date.
Notwithstanding the foregoing, if Tenant's completion of the Tenant Improvements
as set forth in the Work Letter (as defined below), or any subsequent work
letter, is delayed with respect to the Initial Premises, one or more of the
suites comprising the Contingent Premises, or one or more of the suites
comprising the Expansion Space by reason of a Force Majeure Delay or Landlord
Delay (as those terms are defined in the Work Letter), the Commencement Date for
such portion of the Demised Premises so affected shall be delayed by one (1) day
for each day caused by such Force Majeure Delay or Landlord Delay.

                (b) Possession. Possession of any portion of the Building
covered by this Lease shall not be deemed to have occurred unless and until (i)
Landlord's Base Building work as set forth in the work letter attached hereto as
Exhibit D (the "Work Letter") required for such portion of the Building is
substantially complete, (ii) Landlord shall have delivered to Tenant Landlord's
written notice certifying that such Base Building Work is substantially
complete, (iii) such portion of the Building shall be

                                      -5-
<PAGE>   50

broom clean and free of debris and trash, and with all construction equipment,
tools and supplies removed therefrom (except with respect to any continuing work
required by Article 12.4), and (iv) Tenant shall have access to such portion of
the Building (including, without limitation, the freight elevator) as may be
required to allow Tenant to proceed with the construction of its tenant
improvements therein. Possession by Tenant prior to the Commencement Date shall
be subject to all of the provisions of the Lease except that it shall not
advance or extend the Commencement Date or the Expiration Date.

                (c) Contingent Premises. Landlord's obligation to deliver each
of the suites comprising the Contingent Premises is subject to the contingency
set forth below corresponding to the each particular suite:

                        (i) Suite 200 -- Either of the following has occurred:

                                (A) Landlord has (1) obtained the necessary
government approvals to reconstruct the mechanical penthouse of the Building,
shown on Exhibit A-3 attached hereto, for tenant occupancy and the cost of such
reconstruction shall not exceed $40.00 per rentable square foot of space in such
penthouse area; and (2) obtained on or before February 1, 1994 the agreement of
the current tenant of Suite 200 to relocate its premises to such penthouse area
at a base rental rate of not less than $2.08 per square foot per month for a
minimum term of seven (7) years (and in the event Landlord does not obtain such
agreement on or before February 1, 1994, Tenant shall have the option to exclude
Suite 200 from the Demised Premises, which option may be exercised by notice to
Landlord given at any time prior to Landlord entering into such an agreement
with the existing tenant of Suite 200); and (3) elected, in Landlord's sole
judgment reasonably exercised, to enter into such new lease with the current
tenant of Suite 200. In the event Landlord elects not to enter into such new
lease, Tenant shall have the right, exercised within ten (10) business days
following notice of Landlord's decision, to include such penthouse area in the
Demised Premises on the following terms and conditions: the Base Monthly Rent
(as hereinafter defined) shall be $2.08 per rentable square foot per month; the
lease term shall be for eighty four (84) months; and the Tenant Improvement
Allowance shall be $40.00 per rentable square foot with Tenant responsible for
all Base Building Work (as defined in the Work Letter); provided, however, if
the collective lease terms last offered to the current tenant of Suite 200 are
more favorable than the foregoing terms and conditions, Tenant shall have the
right to include such penthouse area in the Demised Premises on such more
favorable terms and conditions. In the event Tenant declines to exercise such
right, Landlord shall be free to lease such penthouse space to a third party on
such terms or on any other terms and conditions acceptable to Landlord in its
sole discretion.

                                      -6-
<PAGE>   51

                                (B) Landlord has obtained the consent of the
current tenant of Suite 200 to terminate its lease early and vacate the
Building, without payment of any lease termination fee or other charge payable
by Landlord to such tenant. The Tenant Improvement Allowance with respect to
Suite 200 shall be discounted by .83 percent per month for the period commencing
with the date of delivery of possession (as defined in Article 1.6(b)) of Suite
200 to and including April 30, 1995.

                        (ii) Suite 204 -- Landlord must obtain the consent of
the current tenant of Suite 204 to terminate its lease and vacate the Building,
without payment of any lease termination fee or any other charge payable by
Landlord to such tenant. Upon delivery of possession (as defined in Article
1.6(b)) of Suite 204 to Tenant, Tenant shall pay to Landlord a lump sum in the
amount of $250 per month from the date of early termination of the lease of the
current tenant of Suite 204 to and including October 14, 1994.

In each case, Landlord shall use its reasonable efforts to satisfy the
contingency applicable to each such Suite and shall regularly inform Tenant of
the status thereof.

        1.7 Late Delivery. If for any reason Landlord cannot deliver possession
of the Initial Premises (excluding Suites 301 and 305) within ten (10) business
days following the date of this Lease, this Lease shall not be void or voidable,
nor shall Landlord be liable for any loss or damage as a result thereof. If for
any reason other than a Force Majeure Delay (as defined in the Work Letter)
Landlord cannot deliver possession of the Initial Premises (excluding Suites 301
and 305) on or before sixty (60) days following said ten (10) business day
period, either Landlord or Tenant may terminate this Lease by giving the other
written notice of termination at any time thereafter and prior to delivery of
possession. If for any reason Landlord cannot deliver possession of the
Contingent Premises within one hundred eighty (180) days following the execution
and delivery of this Lease, this Lease shall not be void or voidable, nor shall
Landlord be liable for any loss or damage as a result thereof; provided,
however, either Landlord or Tenant may terminate this Lease with respect to the
Contingent Premises by giving the other written notice of termination at any
time thereafter and prior to delivery of possession.

        1.8 Option to Extend. Landlord hereby grants Tenant an option to extend
the term with respect to the Demised Premises for one (1) additional period of
five (5) years. Such option to extend the term shall be referred to herein as
the "Extension Option," and the five (5) year period of such Extension Option
shall be referred to herein as the "Option Term." The Option Term shall commence
on the day following the Expiration Date. The Extension Option is subject to and
conditioned upon each of the following:

                                      -7-
<PAGE>   52

                (a) Notice of Exercise. Tenant must notify Landlord in writing
of its exercise of the Extension Option, and such written notice must be given
on or before the date that is nine (9) months prior to the Expiration Date.

                (b) Terms. Tenant's occupancy of the Demised Premises pursuant
to the exercise of the Extension Option shall be upon all of the same terms and
conditions contained in this Lease, except that there shall be no further option
to extend the term of this Lease, the Base Monthly Rent shall be adjusted to
equal ninety five percent (95%) of the Fair Market Rent for the Demised Premises
being extended, the Base Year shall be the calendar year in which such Option
Term commences if such Option Term commences within the first six (6) months of
a calendar year or the calendar year following the year in which such Option
Term commences if such option Term commences in the final six (6) months of a
calendar year, and the Tenant Improvement Allowance shall be as set forth below.
The term "Fair Market Rent" for the Demised Premises for the Option Term
applicable thereto shall mean the "fair market" base rent at the commencement of
the Option Term for the Demised Premises for a term equal to the Option Term,
based on the prevailing rental rates then being charged in arms'-length
transactions for new leases and for lease renewals or extensions (so long as
such renewals or extensions are based on then current fair market rental value
or the rental rates thereunder are adjusted to compensate for any discounts from
fair market rental value provided for in any renewal or extension) of comparable
space and having a term similar to the Option Term (i) in the Building, and (ii)
in comparable buildings in the greater San Rafael area ("Comparable Buildings").
To the extent there are both comparable new leases and lease renewals and
extensions for leased premises in excess of 10,000 square feet, the comparables
for lease renewals and extensions shall be given priority. Concessions or
inducements then being offered in arms'-length transactions in the Building or
in Comparable Buildings shall be considered in determining Fair Market Rent,
including, without limitation, "free rent" periods, improvement or refurbishment
allowances then being given by Landlord or landlords of Comparable Buildings for
comparable space and comparable lease terms (but giving due regard to the value
of the then existing tenant improvements in the Demised Premises and existing
tenant improvements in Comparable Buildings), moving allowances, and other cash
payments from a landlord to or on behalf of a tenant, such as payments for lease
takeovers. Fair Market Rent shall also take into account leasing commissions,
attorneys' fees, or other transaction costs that may be saved by Landlord by way
of such extension compared with leasing space to a new tenant. In the event
Tenant exercises its Extension Option, landlord hereby agrees to pay to Tenant
$5.00 per rentable square foot of the Demised Premises (plus any Expansion Space
then extended) as a Tenant Improvement Allowance for refurbishment of the
improvements in the Demised Premises pursuant to a work letter substantially
similar to the Work Letter attached hereto as Exhibit D. Any

                                      -8-
<PAGE>   53

unused or unfunded portion of such Tenant Improvement Allowance shall be
available to Tenant as a credit against the Base Monthly Rent first due and
payable during the Expansion Option term. Notwithstanding anything to the
contrary contained in this Article 1.8, in no event shall the Fair Market Rent
be less than the Base Monthly Rent for the Demised Premises immediately prior to
the commencement of the Option Term.

                (c) Fair Market Rent. Fair Market Rent shall be determined in
the following manner:

                        (i) The actual Fair Market Rent for such Option Term
shall be specified by Landlord in a written notice ("Landlord's Rent
Determination Notice") given to Tenant not less than ninety (90) days prior to
commencement of the option Term, subject to Tenant's right of arbitration as set
forth below.

                        (ii) The parties shall have a period of twenty (20) days
after the Landlord's Rent Determination Notice within which to negotiate and
attempt to agree upon the Fair Market Rent for the Demised Premises. If the
parties are unable to agree upon the Fair Market Rent for the Demised Premises
within twenty (20) days after Landlord's Rent Determination Notice, then both
Landlord and Tenant shall each designate, within ten (l0) days of the lapse of
such twenty (20) day negotiation period, a real estate broker licensed in the
State of California and engaged in the office brokerage business in Marin County
for at least the immediately preceding five (5) years. If one party fails to
notify the other of its designated broker, the broker designated on a timely
basis shall be the sole broker to determine the issues. In the event that two
brokers are chosen, the brokers so chosen shall meet within ten (l0) business
days after the second broker is appointed, and if within ten (10) business days
after such first meeting the brokers shall be unable to agree upon the Fair
Market Rent, they shall appoint a third broker, who shall be a competent anal
impartial person with qualifications similar to those required of the first two
brokers pursuant to this Article. Each of said three brokers shall, within
fifteen (15) days after the appointment of the third broker, determine the Fair
Market Rent for the Demised Premises for a term equal to Option Term. The Fair
Market Rent shall be the arithmetic average of such three determinations;
provided, however, that if any such broker's determination deviates more than
ten percent (10%) from the median of such determinations, the Fair Market Rent
shall be equal to the average of the two closest determinations.

                (d) Arbitration Fees. Landlord shall pay the costs and fees of
Landlord's broker in connection with any determination of Fair Market Rent
hereunder, and Tenant shall pay the costs and fees of Tenant's broker in
connection with such determination. The costs and fees of any third broker shall
be paid one-half by Landlord and one-half by Tenant.

                                      -9-
<PAGE>   54

                (e) Late Rent Determination. If the amount of the Fair Market
Rent is not known as of the commencement of the option Term, then Tenant shall
continue to pay the Base Monthly Rent for the Demised Premises in effect at the
time of Landlord's Rent Determination Notice until the amount of the Fair Market
Rent is determined. When such determination is made, if Tenant has underpaid the
Base Monthly Rent applicable for the Option Term, Tenant shall pay such
deficiency to Landlord upon demand, or if Tenant has overpaid such Base Monthly
Rent, Landlord shall, at Tenant's option, credit such overpayment in full
against Tenant's payment of Base Monthly Rent next coming due hereunder or, to
the extent such overpayment exceeds one months Base Monthly Rent, credit one
months Base Monthly Rent against Tenant's payment of Base Monthly Rent next
coming due hereunder and pay the balance of such overpayment to Tenant upon
demand.

                (f) No Default. Tenant's right to exercise the Extension Option
is subject to the condition precedent that there is no outstanding uncured
default by Tenant under this Lease at the time of exercise of such right.

        1.9 Right to Terminate. Landlord hereby grants Tenant a one-time right
to terminate this Lease ("Termination Right"), such termination to be effective
on September 30, 1999; provided, Tenant notifies Landlord in writing of the
exercise of its Termination Right on or before December 31, 1996, and pays to
Landlord on or before September 30, 1999 a one-time termination fee equal to
$7.00 per rentable square foot of space then currently comprising the Demised
Premises. Tenant's Termination Right is subject to the condition precedent that
there is no uncured default by Tenant under this Lease at the time of exercise
of such right.

        1.10 Base Monthly Rent. From and after the date that is one (1) month
following the Commencement Date for each particular suite(s) comprising the
Demised Premises, Tenant shall pay to Landlord during the term rent in the
amount of $1.70 per rentable square foot per month (the "Base Monthly Rent");
provided, however, with respect to Suite 306, the Base Monthly Rent shall
commence two (2) months following the Commencement Date for the balance of the
suites comprising the Initial Premises, unless Tenant occupies Suite 306 for
business purposes prior to the expiration of said two (2) month period, in which
case the Commencement Date for Suite 306 shall be the later of (i) such date of
occupancy, or (ii) one (1) month following the Commencement Date for the balance
of the suites comprising the Initial Premises.

        1.11 Payment Dates. Base Monthly Rent shall be payable by Tenant in
consecutive monthly installments on or before the first day of each month, in
advance, at the address specified for Landlord in the Lease Terms, or such other
place as Landlord shall designate, without any prior demand therefor and without
any abatement, deduction or setoff whatsoever except as otherwise

                                      -10-
<PAGE>   55

expressly provided in this Lease. If one or more of the respective Commencement
Dates should occur on a day other than the first day of a calendar month, or one
or more of the respective Expiration Dates should occur on a day other than the
last day of a calendar month, then the rental for such fractional month shall be
prorated on a daily basis based upon the number of days in such month. In
addition to the Base Monthly Rent, Tenant shall pay the amount of any rental
adjustments and additional payments as and when hereinafter provided in this
Lease.

        1.12 Interest; Late Charges. Notwithstanding any other provisions of
this Lease, for the second and each subsequent time within any calendar year
that any installment of Base Monthly Rent or additional charges is not paid to
Landlord within five (5) days after the same is due hereunder, said installment
or additional charge shall bear interest from the date due or from the date of
expenditure by Landlord for the account of Tenant, until the same have been
fully paid, at a rate (the "Default Rate") that is equal to the lesser of (i)
two percent (2%) above the rate of interest publicly announced from time to time
by Bank of America N.T.& S.A. at its San Francisco headquarters as its
"Reference Rate" for commercial borrowing adjusted monthly on the first day of
each month, such adjustment to be effective for the following month, and (ii)
the highest rate permitted by law. The payment of such interest shall not
constitute a waiver of any default by Tenant hereunder. In addition to such
interest, Tenant acknowledges that the late payment by Tenant of any installment
of Base Annual Rent or additional charges not paid to Landlord when due
hereunder will cause Landlord to incur certain costs and expenses not
contemplated under this Lease, the exact amount of which costs being extremely
difficult or impractical to fix. Such costs and expenses will include, without
limitation, administrative and collection costs, and processing and accounting
expenses. Therefore, for the second and each subsequent time within any calendar
year that any installment of Base Annual Rent or additional charges is not
received by Landlord from Tenant within five (5) days after the same is due,
Tenant shall immediately pay to Landlord a late charge equal to five percent
(5%) of the amount due. Landlord and Tenant agree that this late charge
represents a reasonable sum considering all the circumstances existing on date
of this Lease, including the relationship of the sum to the loss to Landlord
that could reasonably be anticipated by such non-payment by Tenant and the
anticipation that proof of actual damages would be costly or inconvenient.
Acceptance of this late charge shall not constitute a waiver of Tenant's default
with respect to such non-payment by Tenant nor shall it prevent Landlord from
exercising all other rights and remedies available to Landlord under this Lease.

                                      -11-
<PAGE>   56

2.      OCCUPANCY

        2.1 Purpose. Tenant shall use and occupy the Demised Premises for the
purpose set forth in Article I of Section I and for no other purpose without the
prior consent of Landlord.

        2.2 Common Areas. Except as otherwise specifically set forth in this
Lease, the manner in which the Common Areas are used, maintained and operated
and the expenditures therefor shall be at the sole and reasonable discretion of
Landlord, governed by the terms of this Lease.

        2.3 Right to Change Common Areas. The purpose of the attached Exhibits
A-1, A-2, A-3 and B is only to show the approximate location of the Demised
Premises in the Building, and such exhibits are not meant to constitute an
agreement as to the specific location of the Common Areas or the elements
thereof or of the accessways to the Demised Premises or the Site. Landlord
hereby reserves the right, at any time and from time to time, to (a) make
alterations in or additions to the Site and the Common Areas, including without
limitation, adding additional office space or other improvements to the parking
garage provided existing parking ratios remain the same, changes in the
location, size, and shape of driveways, entrances, parking spaces, parking
areas, loading and unloading areas, landscaped areas and walkways, (b) close
temporarily any of the Common Areas for maintenance purposes as long as
reasonable access to the Demised Premises remains available, (c) designate
property outside the Site to be part of the Common Areas, (d) use the Common
Areas while engaged in making alterations in or additions or repairs to the
Site, and (e) change the arrangement and location of entrances or passageways,
corridors, stairs, toilets and other public parts of the Building; provided,
however, in no event shall Landlord make any changes to the Common Areas that
would materially adversely affect the Demised Premises, the parking areas of the
Building, or any services provided to the Demised Premises by the Building
Systems (as defined in Article 4.1 below), or that would diminish the ability of
Tenant to enter the Building or to use the Demised Premises. Tenant agrees that
no diminution of light, air or view by any such parking garage improvements or,
any structure that may be erected on property not on the Site after the
Commencement Date for the Initial Premises shall entitle Tenant to any reduction
of Base Monthly Rent or result in any liability of Landlord to Tenant.

        2.4 Common Area Easements. Landlord reserves the right from time to time
to grant such easements, rights and dedications as Landlord deems necessary or
desirable, and to cause the recordation of parcel maps and covenants, conditions
and restrictions affecting the Site, as long as such easements, rights,
dedications, maps and covenants conditions and restrictions do not unreasonably,
interfere with the use of the Demised Premises, the Building, or the parking
areas of the Building by Tenant. The

                                      -12-
<PAGE>   57

Building and the Site may be known by any name that Landlord may choose, which
name may be changed from time to time in Landlord's sole discretion; provided,
however, Landlord shall not name or allow anyone else to name the Building after
any other tenant in the Building so long as Tenant occupies at least 70,000
square feet of rentable space in the Building; and further provided that any
name for the Building shall not be a part of the official nailing address for
tenants of the Building.

        2.5 Use of Parking Spaces. The parking spaces to be provided to Tenant
pursuant to Article L of Section I shall be used for parking only by vehicles no
larger than full-sized passenger automobiles, commute vans, or pick-up trucks.
Tenant shall not permit or allow any vehicles that belong to or are controlled
by Tenant or Tenant's employees, suppliers, shippers, customers or invitees to
be loaded or parked in areas other than those designated by Landlord for such
activities. If Tenant permits or allows any of the prohibited activities
described in this Article 2.5, Landlord shall have the right, in addition to all
other rights and remedies that it may have under this Lease, to remove or tow
away the vehicle involved if such vehicle has not been removed within three (3)
hours after receipt by Tenant of notice (written or telephonic) to Tenant and
the cost thereof shall be paid to Landlord within ten (10) days after notice
from Landlord to Tenant.

3.      ASSIGNMENT, MORTGAGE, SUBLETTING

        3.1 Consent Required. Neither Tenant, nor Tenant's legal
representatives, successors or assigns shall mortgage or encumber this Lease,
and any such mortgage or encumbrance shall be voidable, at the option of
Landlord. Except as provided below, neither Tenant, nor Tenant's legal
representatives, successors or assigns, shall assign this Lease, or sublet, or
use or occupy or permit the Demised Premises or any part thereof to be used or
occupied by others, without the prior consent of Landlord, which consent shall
not be unreasonably withheld, conditioned, or delayed. Any assignment, sublease
or permission without such consent shall be voidable, at the option of Landlord.
If this Lease shall be assigned, or if the Demised Premises or any part thereof
shall be sublet or occupied by any party other than Tenant, Landlord may, after
default by Tenant and the failure to cure such default during any applicable
cure periods, collect rent from the assignee, subtenant or occupant and apply
the net amount collected to the rent herein reserved, but no such assignment,
subletting, occupancy or collection shall be deemed a waiver of this covenant,
or the acceptance of the assignee, subtenant or occupant as Tenant, or a release
of Tenant from the further performance by Tenant of the obligations on the part
of Tenant herein contained. Any sale or other transfer, including transfer by
consolidation, merger or reorganization, of a majority of the voting stock of
Tenant, if Tenant is a corporation, or any sale or other transfer of a

                                      -13-
<PAGE>   58

majority of the partnership interests in Tenant, if Tenant is a partnership,
shall not be an Assignment for purposes of this Article 3; and therefore, shall
not require the prior consent of Landlord. No assignment, whether with or
without Landlord's consent, shall relieve Tenant from its covenants and
obligations under this Lease.

        3.2 Grounds for Denying Consent. Notwithstanding any contrary provision
of the foregoing, it shall be reasonable for Landlord to deny such consent to an
assignment or sublet in the following circumstances:

                        (i) The use to be made of the Demised Premises by the
                proposed assignee (a) violates the terms of Article 2, or (b) a
                use which conflicts with any so-called "exclusive" then in favor
                of, or for any use which is the same as that stated in any
                percentage lease to, another tenant of the Building or the Site,
                or (c) a use which would be prohibited by any other portion of
                this Lease (including but not limited to any Rules and
                Regulations then in effect): or

                        (ii) The financial responsibility of the proposed
                assignee (as opposed to a proposed subtenant) is not reasonably
                satisfactory to Landlord.

        3.3 Further Conditions to Assignment. Tenant's right to assign this
Lease are further conditioned upon the following:

                (i) That Tenant shall reimburse Landlord for all reasonable
attorney's fees incurred by Landlord in connection therewith, whether or not
such proposed assignment is consented to by Landlord;

                (ii) That the proposed assignee shall execute an agreement
pursuant to which it shall agree to perform faithfully and be bound by all of
the terms, covenants, conditions, provisions and agreements of this Lease;

                (iii) That an executed duplicate original of said assignment and
assumption agreement shall be delivered to Landlord within five (5) days after
the execution thereof, and that such assignment shall not be binding upon
Landlord until the delivery thereof to Landlord and the execution and delivery
of Landlord's consent thereto; and

                (iv) That the consent by Landlord to an assignment shall not be
construed to relieve Tenant or the assignee from obtaining the express consent
in writing of Landlord to any further assignment or to release Tenant from any
liability whether past, present or future under this Lease or to release Tenant
from any liability under this Lease because of Landlord's failure to

                                      -14-
<PAGE>   59

give notice of default under or in respect of any of the terms, covenants,
conditions, provisions or agreements of this Lease.

Notwithstanding any provision contained in this Lease to the contrary, Tenant
shall have the right, without Landlord's consent, to assign this Lease or sublet
all or a portion of the Demised Premises to any parent or subsidiary of Tenant,
to any person, firm or corporation which shall be controlled by, under the
control of, or under, control with Tenant, or to any corporation into which
Tenant may be merged, consolidated or which purchases all or substantially all
of the assets of Tenant.

        3.4 Right to Share Rent. Notwithstanding the foregoing provisions of
this Article 3 and without relinquishing or diminishing any of Landlord's rights
of prior approval, in the event that Landlord consents to an assignment of this
Lease or a sublease of all or any part of the Demised Premises, and Tenant
receives rent in connection with such assignment or sublease which exceeds the
Base Monthly Rent (or the pro rata portion thereof) or receives cash or other
consideration in respect of such assignment or sublease, Tenant shall pay to
Landlord when and as received fifty percent (50%) of any such excess rent or
other consideration reduced only by leasing commissions not to exceed standard
leasing commissions then payable for comparable space in the central Marin
County area.

4.      ALTERATIONS

        4.1 Alterations. Tenant shall make no alterations, decorations,
additions or improvements in or to Demised Premises without Landlord's prior
written consent, which consent shall not be unreasonably withheld or
conditioned; and then only by contractors or mechanics reasonably approved in
advance in writing by Landlord Tenant shall submit such information as Landlord
shall reasonably require, including, without limitation (i) plans and
specifications, (ii) evidence of insurance coverage in such types and amounts
and from such insurers as other owners of Comparable Buildings may require and
(iii) all permits and licenses required in connection with such work; provided,
that Tenant shall not be required to pay to Landlord any fee for Landlord's
review of such documents or information (including architectural or engineering
drawings). Landlord shall within ten (10) business days following receipt of
such plans review and provide to Tenant written comments to such plans. Failure
of Landlord to respond with written comments within such ten (10) business days
shall constitute Landlord's approval of said plans and, to the extent such
improvements are the type with respect to which Landlord has the right to give a
Removal Notice (as defined below), such failure shall also constitute Landlord's
Removal Notice with respect to such improvements. Notwithstanding the
foregoing, Tenant may, without the Landlord's consent, but with prior notice to
Landlord

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<PAGE>   60

containing such plans, cost estimate and other information reasonably requested
by Landlord, make any cosmetic, non-structural alterations, additions and
improvements to the Demised Premises and any alterations, conditions and
improvements to the Demised Premises costing less than $50,000 that are
non-structural in nature, do not in any way effect the Building mechanical,
plumbing or electrical systems ("Building Systems"), do not increase the overall
density of individual offices per square foot from the overall density of
individual offices per square foot shown on the Space Plan attached to the Work
Letter as Schedule 1, do not otherwise materially increase the density set forth
in said Space Plan and do not create offices smaller than 9.8' x 11', measured
from centerline to centerline of walls. All such work shall be done at Tenant's
sole cost and expense. All work done by Tenant shall be performed in full
compliance with all laws, rules, orders, ordinances, directions, regulations and
requirements of all governmental agencies, offices, departments, bureaus and
boards having jurisdiction (including but not limited to the Americans with
Disabilities Act of 1990, Pub. L. 101-336 and other similar laws from time to
time in effect), and in full compliance with the rules, orders, directions,
regulations and requirements of the insurance underwriters or other governmental
authority having jurisdiction thereof which are necessary for the maintenance of
all-risk property insurance for the Demised Premises (the "Insurance
Underwriters"). Before commencing any work, Tenant shall give Landlord at least
ten (10) days' written notice of the proposed commencement of such work in order
to give Landlord an opportunity to prepare, post and record such notice as may
be permitted by law to protect Landlord from having its interest in the Demised
Premises, the Building or the Site made subject to a mechanic's lien and, at
Landlord's election with respect to any work costing more than $50,000 and at a
time when the current ratio (current assets to current liabilities) of Tenant is
less than 1.5 to 1, shall deposit the total budgeted cost for all such
alterations, decorations, additions or improvements in an escrow account for
disbursement pursuant to the procedure set forth in Section 8(b) of the Work
Letter (in lieu of such escrow procedure, Tenant may secure, at Tenant's own
cost and expense, a completion and lien indemnity bond, satisfactory to
Landlord, for said work). Any mechanic's lien filed against the Demised Premises
or against the Building or the Site or any of the areas used in connection with
the operation of the Building for work claimed to have been done for, or
materials claimed to have been furnished to Tenant, shall be discharged by
Tenant, by bond or otherwise, within fifteen (15) days after the filing thereof,
at the cost and expense of Tenant. All alterations, decorations, additions, or
improvements upon the Demised Premises, made by Tenant, including, without
limiting the generality of the foregoing, all panelling, partitions, railings,
mezzanine floors, galleries and the like, shall become the property of Landlord,
and shall remain upon, and be surrendered with the Demised Premises, as a part
thereof, at the end of the term; provided, however, Landlord shall have the
right

                                      -16-
<PAGE>   61

to require Tenant to remove such alterations by giving Tenant notice (the
"Removal Notice") at the time of consent to such alterations, and then only to
the extent that such alterations do not increase the overall density of
individual offices per square foot shown on the Space Plan attached to the Work
Letter as Schedule 1, do not otherwise materially increase the density set forth
in said Space Plan and do not create offices smaller than 9.8' x 11', measured
from centerline to centerline of walls. Notwithstanding any terms to the
contrary contained in this Lease, Tenant shall be required at the expiration or
earlier termination of this Lease, to remove at its sole cost and expense any
personal property of Tenant, exterior signage installed by Tenant, computers and
related equipment including peripheral equipment and tape and disk vaults, all
projectors and projection screens and related equipment, blackboards,
whiteboards, tack boards, and other display units, telephone systems (excluding
wiring), electronic security systems (excluding wiring), paging systems
(excluding wiring), phone system equipment including patch panel and subfeed
panel locations for such phone systems, CRT patch panels and all other trade
fixtures of Tenant, and those improvements with respect to which Landlord has
given the Removal Notice.

5.      REPAIRS

        5.1 Tenant Repairs. Subject to Landlord's repair and maintenance
obligations set forth in this Lease, Tenant shall, except for ordinary wear and
tear, make all repairs in and about the Demised Premises necessary to preserve
them in good order and condition, which repairs shall be in quality and class
equal to or better than the original work. Such repairs shall include, without
limitation, fixtures, interior walls, interior surfaces of exterior walls
(however excluding windows and window gaskets), plumbing and sewage facilities
and equipment (including all sinks, toilets, faucets and drains), excluding only
the water and sewage distribution lines in the Building, and doors located
within the Demised Premises. Notwithstanding the foregoing provisions of this
Article 5.1, Tenant shall not be responsible for any repairs or maintenance, (i)
to the extent made necessary by any defects in the Building or Demised Premises
(excluding defects in the tenant improvements constructed by Tenant), (ii)
covered by Landlord's insurance or which would be covered under the insurance
Landlord is required to carry under Article 14.4, whichever is greater, (iii)
required as the result of the negligence or willful misconduct of Landlord or
Landlords agents, servants, employees, licensees, invitees, contractors or
subcontractors or (iv) made necessary by any default by Landlord under the terms
of this Lease.

        5.2 Landlord Repairs. Landlord shall maintain, in good condition, the
Common Areas, the foundations, exterior walls and roof of the Building, all
window frames and windows, all structural

                                      -17-
<PAGE>   62

elements of the Building, and the Building plumbing (excluding plumbing which
Tenant is required to repair pursuant to Article 5.1), heating, ventilating or
air conditioning and the Building water, sewer and electrical distribution
systems. Landlord shall not be in breach of its obligation to make any repairs
or replacements hereunder until the expiration of thirty (30) days following
written notice from Tenant to Landlord of the need therefor. Except as provided
in Articles 10, 12.3 and 19.1 hereof, there shall be no allowance to Tenant for
a diminution of rental value, and no liability on the part of Landlord by reason
of inconvenience, annoyance or injury to business arising from the making of, or
the failure to make, any repairs, alterations, decorations, additions or
improvements in or to any portion of the Building or any of the areas used in
connection with the operation thereof, or the Demised Premises, or in or to
fixtures, appurtenances or equipment, or by reason of the act or neglect of
Tenant or any other tenant or occupant of the Building; and in no event shall
Landlord be responsible for any consequential damages arising or alleged to have
arisen from any of the foregoing matters; provided, however, in the event the
Demised Premises (or a portion thereof) are rendered unusable due to any such
repair work by Landlord, Landlord's agents, employees, contractors or third
parties performing such repair work at the Building or Site, then one (1) day of
Base Monthly Rent (or portion thereof according to the part of the Demised
Premises rendered unusable) shall be abated for every day the Demised Premises
(or portion thereof) are rendered unusable. Tenant hereby waives all rights
under the provisions of Sections 1932, 1933, 1941 and 1942 of the Civil Code of
the State of California and all rights under any law in existence during the
term of this Lease authorizing a tenant to make repairs at the expense of a
landlord or to terminate a lease upon the complete or partial destruction of the
leased premises; provided, however, Tenant shall have those rights expressly set
forth in this Lease.

        5.3 Tenant's Failure to Repair. If Tenant fails to perform Tenant's
obligations under Article 5.1, Landlord shall give Tenant notice of such acts as
are reasonably required to fulfill such obligations. If Tenant fails to commence
the work within thirty (30) days after notice and diligently prosecute the work
to completion, then Landlord shall have the right (but not the obligation) to do
such acts or expend such funds at the expense of Tenant as are reasonably
required to perform such work.

6.      REQUIREMENTS OF LAW, INSURANCE

        6.1 Requirements of Law. Tenant, at Tenant's expense, shall comply with
all laws, rules, orders, ordinances, directions, regulations and requirements of
federal, state, county and municipal authorities (collectively, "Laws," or
individually, a "Law") pertaining to Tenant's use of the Demised Premises and
with

                                      -18-
<PAGE>   63

any recorded covenants, conditions and restrictions affecting the Site, and with
any direction of any public officer or officers, pursuant to law, which shall
impose any duty upon Landlord or Tenant with respect to the use or occupation of
the Demised Premises, and shall not do or permit to be done, any act or thing
upon the Demised Premises, which will invalidate or be in conflict with any
insurance policy covering the Building or any of the areas used in connection
with the operation thereof or its fixtures, appurtenances or equipment or the
property located therein, and shall not do or permit it be done, any act or
thing upon the Demised Premises which shall or might subject Landlord to any
liability or responsibility for injury to any person or persons or to any
property by reason of any business or operation being carried on upon the
Demised Premises; provided, however, that Tenant shall not be required to make
any alterations of or improvements to the Demises Premises or to the Building
(structural or otherwise) in order to so comply unless such alterations or
improvements shall (i) be necessitated or occasioned by the particular nature or
manner of Tenant's use of the Demised Premises; or (ii) relate to Tenant's
failure to comply with Laws with respect to alterations made by Tenant pursuant
to Article 4 hereof or tenant improvements made by Tenant pursuant to the Work
Letter or any subsequent work letter between Landlord and Tenant, including but
not limited to the Americans with Disabilities Act of 1990, Pub. L. 101-336 and
other similar laws from time to time in effect. Tenant shall not place a load
upon any floor of the Demised Premises exceeding the floor load per square foot
area which such floor was designed to carry and which is allowed by law.

        6.2 insurance Underwriters. Tenant shall comply with all rules, orders,
directions, regulations and requirements of the Insurance Underwriters or any
other similar body, and shall not do, or permit anything to be done, in or upon
the Demised Premises, or bring or keep anything therein, which shall increase
the rates of any insurance on the Building or any of areas used in connection
with the operation thereof or its fixtures, appurtenances or equipment or on
property located therein. If by reason of failure of Tenant to comply with the
provisions of this Article, any insurance rate shall at any time be higher than
it otherwise would be, then Landlord shall provide Tenant written notification
of such increase together with reasonable documentation demonstrating such
increase and Tenant's actions as the cause thereof. Tenant shall have fifteen
(15) days from receipt of such notice to either remedy such action that caused
such increase in insurance premiums or to reimburse Landlord for such increase.
To the extent that such action remains unremedied, Tenant shall promptly pay
such increased insurance premiums when and as incurred by Landlord. In any
action or proceeding wherein Landlord and Tenant are parties, a schedule or
"make-up" of rate for the Building or the Demised Premises issued by the
Insurance Underwriters, or other body making insurance rates for the Building or
the Demised Premises, shall be conclusive evidence of the facts therein stated
and of the several

                                      -19-
<PAGE>   64

items and charges in the insurance rate than applicable to the Demised Premises.

        6.3 ADA Requirements. Tenant hereby agrees to perform all work to the
areas within the Demised Premises so as to comply with the then current
requirements of the Americans with Disabilities Act of 1990, Pub. L. 101-336 and
other similar laws from time to time in effect); and notwithstanding anything to
the contrary contained in the Lease, Landlord hereby agrees to perform all work
to the Building (excluding the Demised Premises) and the Common Areas,
including, without limitation, all entryways, all bathrooms in the Building, and
all hallways, so as to comply, in Landlord's reasonable judgment, with the
current requirements of the Americans with Disabilities Act of 1990, Pub. L.
101-336 and other similar laws from time to time in effect). Both parties agree
to perform their respective obligations herein in a timely manner so as to not
to interfere with the use or occupancy of the Demised Premises or the Building.

7.      SUBORDINATION, MORTGAGES, NONDISTURBANCE

        7.1 Subordination. This Lease is subject and subordinate to (i) all
ground or underlying leases, mortgages and deeds of trust which now affect the
real property of which the Demised Premises forms a part or affect the ground or
underlying leases, (ii) all renewals, modifications, consolidations,
replacements and extensions thereof, and (iii) any ground or underlying leases,
mortgages, or deeds of trust which may hereafter affect the real property of
which the Demised Premises forms a part or affect the ground or underlying
leases; provided, however, that it shall be a condition precedent to such
subordination that Tenant receive from such lessor, mortgagee or beneficiary a
fully executed original of the Subordination, Non-Disturbance and Attornment
Agreement specified in Article 7.4 below.

        7.2 Mortgages. In the event of foreclosure or exercise of power of sale
under any mortgage or deed of trust now or hereafter affecting the real property
of which the Demised Premises forms a part, Tenant shall attorn to such holder
or purchaser; provided, however, that it shall be a condition precedent to such
attornment that Tenant receive from such lessor, mortgagee or beneficiary a
fully executed original of the Subordination, Non-Disturbance and Attornment
Agreement specified in Article 7.4 below, or (b) notwithstanding this Article,
such holder or purchaser may elect that this Lease become or remain, as the case
may be, superior to said mortgage or deed of trust.

        7.3 Further Assurances. Tenant shall, upon request by any such holder or
purchaser, execute and deliver any and all reasonable instruments desired by
such holder or purchaser

                                      -20-
<PAGE>   65

evidencing the superiority of this Lease to any said mortgage or deed of trust.

        7.4 Nondisturbance. Notwithstanding anything to the contrary herein
contained, any ground or underlying lease, mortgages or deeds of trust which
may hereafter affect the real property of which the Demised Premises forms a
part, or affect the ground or underlying leases, this Lease shall not be subject
or subordinate thereto unless and until Landlord obtains from the mortgagee
under this mortgage, beneficiary under the deed of trust, ground lessor under
any ground lease or other secured party under any other security instrument or
arrangement placed against the Demised Premises, a Subordination,
Non-Disturbance and Attornment Agreement substantially in the form of Exhibit E
attached hereto, or after using its best efforts, landlord is unable to obtain
such agreement, then with such reasonable changes as the secured party may
request provided such changes do not materially increase the obligations of
Tenant under this Lease, or otherwise have a material adverse affect upon
Tenant's rights under this Lease. Tenant shall, upon request by Landlord,
execute and deliver a Subordination, Non-Disturbance and Attornment Agreement in
the form required by this Article 7.4.

8.      RULES AND REGULATIONS

        8.1 Rules an Regulations. Tenant and Tenant's Agents, servants,
employees, visitors and licensees shall observe faithfully and comply strictly
with the Rules and Regulations attached hereto as Exhibit F, and such other and
further reasonable Rules and Regulations as Landlord or Landlords agents may
from time to time adopt. If there is a conflict between the Rules and
Regulations and any provision of this Lease, the provisions of this Lease shall
prevail. Landlord agrees that it will not change or modify the Rules and
Regulations in any way which (i) materially reduces the specific obligations of
Landlord to perform under the terms and conditions of this Lease, (ii)
materially interferes with Tenant's use and enjoyment of the Demised Premises,
or (iii) materially interferes with the conduct of Tenant's normal business
operations. Landlord shall not be responsible to Tenant for the violation or
nonperformance of any Rules and Regulations by any other tenants or occupants
of the Building, but Landlord agrees to apply and administer the Rules and
Regulations in a fair manner. Should any tenant in the Building receive any
waiver or special dispensation from Landlord with regard to the Rules and
Regulations, Tenant shall be entitled to a similar waiver or special
dispensation.

9.      LIABILITY AND INDEMNIFICATION

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<PAGE>   66

        9.1 Tenant Indemnification. Tenant agrees to indemnify Landlord against,
and protect, defend and save Landlord harmless from, any and all loss, cost,
liability, damage and expense, including, without limitation, penalties, fines
and counsel fees, incurred in connection with or arising from any cause
whatsoever in, on or about the Demised Premises, including, without limiting the
generality of the foregoing, (a) any default by Tenant in the observance or
performance of any of the terms, covenants or conditions of this Lease on
Tenant's part to be observed or performed, and (b) the use or occupancy or
manner of use or occupancy of the Demised Premises by Tenant or any person
claiming through or under Tenant, or of the employees, suppliers, shippers,
customers or invitees of Tenant or any such other person, in, on or about the
Demised Premises, the Building or the Site, whether prior to, during, or after
the expiration of, the term including, without limitation, any act, omission or
negligence in the making or performing of any alterations. Tenant further agrees
to indemnify Landlord's agent responsible for the management of the Building,
Common Areas and the Site, against and hold it harmless from any and all loss,
cost, liability, damage and expense including, without limitation, counsel fees,
incurred in connection with or arising from any claims by any persons by reason
of injury to persons or damage to property occasioned by any use, occupancy
condition occurrence, happening, act, omission or negligence referred to in the
preceding sentence.

        9.2 Landlord Indemnification. Landlord agrees to indemnify Tenant
against, and protect, defend and save Tenant harmless from, any and all loss,
cost, liability, damage and expense, including, without limitation, penalties,
fines and counsel fees, incurred in connection with or arising from Landlord's
negligent or willful act in, on or about the Building, including, without
limiting the generality of the foregoing, (a) any default by Landlord in the
observance or performance of any of the terms, covenants or conditions of this
Lease on Landlord's part to be observed or performed, and (b) the negligent use
or occupancy or manner of use or occupancy of the Building by Landlord in, on or
about the Building or the Site, whether prior to, during, or after the
expiration of, the term of the Lease.

        9.3 Limitation of Landlord's Responsibility. Except to the extent caused
by Landlord or Landlord's agents, employees or contractors, Landlord shall not
be responsible for or liable to Tenant for any loss or damage that may be
occasioned by or through the acts or omissions of persons occupying adjoining
premises or any part of the premises adjacent to or connected with the Demised
Premises or any part of the Building, Common Areas or Site or for any loss or
damage resulting to Tenant or its property from burst, stopped or leaking water,
gas, sewer or steam pipes, or for any damage to or loss of property within the
Demised Premises from any causes whatsoever, including latent defects in the
Building, Common Areas, the Site, or the Demised Premises or theft.

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        9.4 Tenant's Payments. Except where a longer or shorter period is
specifically provided for in this Lease for a particular expenditure, Tenant
shall pay to Landlord, within thirty (30) days after delivery by Landlord to
Tenant of bills or statements therefor: (a) sums equal to all expenditures made
and monetary obligations incurred by landlord including, without limitation,
expenditures made and obligations incurred for reasonable counsel fees, in
connection with the remedying by Landlord of Tenants defaults, and (b) sums
equal to all losses, costs, liabilities, damages and expenses referred to in
Article 9.1.

10.     DAMAGE OR DESTRUCTION

        10.1 Damage of Destruction. If the Demised Premises or any portion of
the Building or Site required by Tenant to use the Demised Premises as intended
shall be partially damaged by fire or other cause, the damages shall be repaired
by and at the expense of Landlord and the Base Monthly Rent until such repairs
shall be made shall be apportioned according to the part of the Demised Premises
which is used by Tenant. No liability shall accrue for reasonable delay which
may arise by reason of adjustment of insurance on the part of Landlord or
Tenant, for reasonable delay on account of a Force Majeure Delay (as defined in
the Work Letter), or any other cause beyond Landlord's control; provided,
however, if such damage is not fully repaired within six (6) months, Tenant
shall have the option thereafter to terminate this Lease. If the Demised
Premises are totally damaged or are rendered wholly untenantable by fire or
other cause, and Landlord shall decide not to restore or rebuild the same, or if
the Building shall, in Landlord's reasonable judgment, be so damaged that
Landlord shall decide to demolish it and to rebuild it, then in any of such
events Landlord may, within ninety (90) days after such fire or other cause
which results in structural damage to the Building, or within sixty (60) days
after such fire or other cause which does not result in structural damage to the
Building, give Tenant notice of such decision, and thereupon the term of this
Lease shall expire by lapse of time upon the third day after such notice is
given, and Tenant shall vacate the Demised Premises and surrender the same to
Landlord. If Landlord decides to rebuild the Building, Landlord shall, within
the applicable sixty (60) or ninety (90) day period after such fire or other
cause, give Tenant notice of such decision, and Landlord shall proceed to
rebuild the Building at the expense of Landlord and the Base Monthly Rent until
such reconstruction has been completed shall abate. No liability shall accrue
for reasonable delay which may arise by reason of adjustment of insurance on the
part of Landlord or Tenant, for reasonable delay on account of "labor troubles"
or any other cause beyond Landlord's control; provided, however, if Landlord
does not commence such repairs within three (3) months and diligently pursue
construction of the Building, or if the Building is not completed within six (6)
months of Landlord's decision to rebuild, Tenant shall on or before the

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<PAGE>   68

expiration of such applicable three (3) month or six (6) month period give
Landlord fifteen (15) days prior written notice of its intention to terminate
this Lease, and thereafter Tenant shall have the option to terminate this Lease
if Landlord has not, within said fifteen (15) day period, either commenced or
completed such repairs, whichever is applicable. Notwithstanding anything to the
contrary contained in this Article 10.1, in the event that more than fifty
percent (50%) of rentable square feet of the Demised Premises then leased by
Tenant are totally damaged or are rendered wholly untenantable by fire or other
cause, Tenant may, within thirty (30) days after such fire or other cause, elect
to terminate this Lease by giving Landlord written notice of such decision. Upon
any such termination Tenant shall be entitled to receive reimbursement for the
then current value of the portion of the tenant improvements paid for by Tenant
pursuant to the Work Letter or any subsequent work letter, but only to the
extent of insurance proceeds actually received by Landlord from insurance
required to be carried by Landlord under Article 14.4, and only after Landlord
has received reimbursement for the then current value of such tenant
improvements paid for by Landlord pursuant to the work letter or any subsequent
work letter. Landlord shall diligently pursue recovery of such insurance
proceeds.

        10.2 No Obligation to Rebuild Beyond Insurance. Notwithstanding anything
contained in this Article 10 to the contrary, in no event shall Landlord be
required to spend for any repair, replacement or reconstruction of the Demised
Premises or the Building an amount greater than the insurance proceeds actually
received by Landlord as a result of the fire or other casualty causing such
loss, damage or destruction.

        10.3 Tenant Waivers. The provisions of this Lease, including this
Article 10, constitute an express agreement between Landlord and Tenant with
respect to any and all damage to, or destruction of, all or any part of the
Demised Premises, the Building or any other portion of the Site; and any statute
or regulation of the State of California, including, without limitation,
Sections 1932(2) and 1933(4) of the California Civil Code, With respect to any
rights or obligations concerning damage or destruction in any absence of an
express agreement between the parties, and any similar statute or regulation,
now or hereafter in effect, shall have no application to this lease or to any
damage to or destruction of all or any part of the Demised Premises, the
Building or any other portion of the Site.

        10.4 Waiver of Subrogation. Notwithstanding the provisions of this
Article 10, Landlord waives any and all rights of recovery against Tenant for
or arising out of damage to or destruction of the Building, or the Demised
Premises, from causes then included under standard fire and extended coverage
insurance policies endorsements, whether or not such damage or destruction
shall have been caused by the negligence of Tenant, its agents, servants,

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<PAGE>   69

employees, contractors, visitors or licensees, but only to the extent of
insurance proceeds actually received by Landlord from insurance required to be
carried by Landlord under Article 14.4, for such damage or destruction. Landlord
shall diligently pursue recovery of such insurance proceeds. Tenant waives any
and all rights of recovery against Landlord for or arising out of damage to or
destruction of any property of Tenant, from causes then included under standard
fire and extended coverage insurance policies or endorsements, whether or not
caused by the negligence of Landlord, its agents, servants, employees,
contractors, visitors or licensees. Landlord and Tenant represent that their
insurance policies shall permit such waiver.

       10.5 Loss of Waiver. If at any time during the term of this Lease either
party shall give no less than five (5) days prior notice to the other certifying
that any insurance carrier which shall have issued any such policy covering any
of the property above mentioned shall refuse to consent to the aforesaid waiver
of subrogation, or if such carrier shall consent to such waiver only upon the
payment of an additional premium (and such additional premium is not paid by the
other party hereto), or such carrier shall revoke a consent previously given or
shall cancel or threaten to cancel any policy previously issued and then in
force and effect, because of such waiver of subrogation, then, in any of such
events, such party shall use its best efforts to obtain another policy of
insurance that contains the waiver in this Article 10.

11.   EMINENT DOMAIN

       11.1 Eminent Domain.  If the whole Demised Premises shall be taken or
condemned for all or any portion of the term by any competent authority for any
public or quasi public use or purpose, or transferred by agreement in connection
with such public or quasi public use or purpose with or without any condemnation
action or proceeding being instituted (collectively, a "Taking" or
"Condemnation"), then, the term of this Lease shall terminate as of the date
when the possession of the Demised Premises shall be required for such use or
purpose, and without apportionment of the award, such that the entire award .is
paid to Landlord. The then current rental,  however shall in any such case be
apportioned. Except as otherwise provided in Article 11.2, Tenant hereby
expressly assigns to Landlord any award which may be made in any taking or
condemnation as therein provided, together with any and all rights of Tenant
now or hereafter arising in or to the same or any part thereof.

       11.2 Tenant's Award. Nothing contained herein shall be deemed to give
Landlord any interest in, or to require Tenant to assign to Landlord, any award
made to Tenant specifically,for its relocation expenses, the taking of personal
property and fixtures belonging to Tenant, or the interruption of or damage to
Tenant's

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<PAGE>   70

business if such award is made separately to Tenant and not as part of the
damages recoverable by Landlord.

       11.3 Partial Taking. If any portion of the Demised Premises is taken by
Condemnation, this Lease shall remain in effect, except that Tenant shall have
the right to elect to terminate this Lease if the remaining portion of the
Demised Premises is rendered inaccessible or unusable to Tenant. If any part of
the Common Areas of the Building is taken by Condemnation, this Lease shall
remain in full force and effect so long as there is no material interference
with the access to the Demised Premises. If such a taking materially interferes
with access to the Demised Premises, either party shall have the election to
terminate this Lease. Any termination pursuant to this Article 11.3 shall be as
of the date when the possession of the part so taken shall be required for such
use or purpose, and without apportionment of the award, such that the entire
award is paid to Landlord. The then current rental; however, shall in any such
case be apportioned. Except as otherwise provided in Article 11.2, Tenant hereby
expressly assigns to Landlord any award which may be made in any taking or
condemnation as therein provided, together with any and all rights of Tenant now
or hereinafter arising in or to the same or any part thereof.

       11.4 Restoration. If there is a partial taking of any portion of the
Demised Premises and this Lease remains in full force and effect pursuant to
this Article 11, Landlord, at its cost, shall accomplish all necessary
restoration so that the balance of such portion of the Demised Premises is
returned as near as practical to their condition immediately prior to the date
of Taking.

       11.5 Temporary Taking. If all or any portion of the Demised Premises is
condemned or otherwise taken for public or quasi-public use for a limited period
of time, this Lease shall remain in full force and effect and Tenant shall
continue to perform all terms, conditions and covenants of this Lease. Tenant
shall be entitled to receive the entire award made in connection with any such
temporary condemnation or other taking.

       11.6 Landlord Settlement. Landlord may, without any obligation to Tenant,
agree to sell and/or convey to the condemnor the Demised Premises, the Building,
the Site or any portion thereof sought by the condemnor, free from this Lease
and the rights of Tenant hereunder, condemnor first institutes an action or
proceeding (but there shall be no requirement that such action be pursued to
judgment).

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12.    SERVICES

       12.1 Landlord's Services. Landlord shall:

              (1) Provide automatic elevator facilities on normal business days
from 6:00 a.m. to 6:30 p.m. and have one elevator available at all other times.

              (2) On normal business days from 8:00 a.m. to 6:00 p.m. (and at
other times for the actual then current charge per hour per fan room (which
charge is currently estimated to be $9.32 per hour), as such may be adjusted
annually, provided such charge does not exceed Landlords actual cost with no
mark-up) ventilate the Demised Premises and furnish heating or air conditioning
as required for Tenant's comfortable use and normal occupancy of the Demised
Premises with temperatures between the range of 68 degrees F dry bulb and 76
degrees F dry bulb. Tenant agrees to keep and cause to be kept closed all doors
from the Demised Premises and the windows in the Demised Premises, and Tenant
agrees to cooperate fully at all times with Landlord and to abide by all
reasonable regulations and requirements which Landlord may prescribe for the
proper functioning and protection of the heating, ventilating and air
conditioning system. Tenant shall not install or use in the Demised Premises any
equipment which would generate heat so as to adversely affect the heating,
ventilating and air conditioning system; provided, however, Tenant shall have
the right to use computers and other standard office machines as is customary in
offices of a company that creates and produces computer software as the same may
change from time to time (however, to the extent that such use by Tenant
increases the demands on the heating, ventilating and air conditioning system
beyond the level required by standard office use, Landlord reserves the right to
install supplemental equipment in the Demised Premises to address such increased
use, and to charge Tenant for the cost thereof, and/or any increased costs
relating to such use). Landlord, throughout the term of this Lease, shall have
free access to any and all mechanical installations of Landlord or Tenant,
including, but not limited to, air conditioning, fan, ventilating and machine
rooms, telephone rooms and electrical closets; provided, however, with respect
to any non-emergency situation occurring outside normal business hours, Landlord
shall notify Tenant and afford Tenant the opportunity to have a representative
present during such access if such access is to a room that is located within
the Demised Premises. Tenant agrees that there shall be no construction
partitions or other obstructions which might interfere with Landlords free
access thereto, or interfere with the moving of Landlord's equipment to or from
the enclosures containing said installations. Tenant further agrees that neither
Tenant, nor its agents, servants, employees, contractors, visitors or licensees'
shall at any time enter the said enclosures or tamper with, adjust, touch or
otherwise in any manner affect Landlord's said, mechanical installations.

                                      -27-
<PAGE>   72

              (3) Provide electricity for lighting and normal office business
machines, including, without limitation, computers or electronic data processing
or ancillary equipment. Tenant agrees not to use any apparatus or device in, or
upon, or about the Demised Premises which may in any way increase the amount of
such electricity usually furnished or supplied to said premises and Tenant
further agrees not to connect any apparatus or device to the wires, conduits or
pipes, or other means by which such electricity is supplied, for the purpose of
using additional or unusual amounts of electricity, without prior written
consent of Landlord provided, however, Tenant shall have the right to use
computers and other standard office machines as is customary in offices of a
company that creates and produces computer software as the same may change from
time to time (however, to the extent that such use by Tenant increases the
amount of electricity used in the Demised Premises for standard office-purposes,
Landlord reserves the right to charge Tenant for the increased electricity cost
relating to such use). At all times Tenant's use of electric current shall never
exceed the capacity of the feeders to the Building or the risers or wiring
installation, but Landlord shall not reduce such capacity, risers or wiring
during the term of this Lease for any extension thereof.

              (4) Furnish water for drinking and lavatory purposes only, but if
Tenant requires, uses or consumes water for any purpose in addition to ordinary
drinking and lavatory purposes, Landlord may install a water meter and thereby
measure Tenant's water consumption for all purposes. Tenant shall pay Landlord
for the cost of the meter and the cost of the installation thereof and
throughout the duration of Tenant's occupancy, and Tenant shall keep said meter
and installation equipment in good working order and repair at Tenant's own cost
and expense Tenant agrees to pay for water consumed as shown on said meter
as and when bills are rendered and on default in making such payment, Landlord
may, pay such charges and collect the same from Tenant.

              (5) Cause the Demised Premises and the Common Areas to be kept
clean and neat in accordance with the specifications set forth on Exhibit G
attached hereto Tenant shall pay to Landlord the cost of removal of any of
Tenant's refuse and rubbish to the extent that the same exceeds the refuse and
rubbish usually attendant upon the use of the Demised Premises exclusively as
ordinary desk type offices.

              (6) Maintain the Women and Men's public restrooms in the Building
in a clean and sanitary condition, including the furnishing of soap, paper
towels, toilet tissue and other restroom supplies customarily supplied in
Comparable Buildings.

              (7) Landlord install at Landlords expense replacement Building
standard fluorescent bulbs, light bulbs and ballasts as needed in the Demised
premises and the Common areas.

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<PAGE>   73

       12.2 Notice of Shut-Downs. Landlord shall notify Tenant in writing at
least twenty-four (24) hours before any intentional shut-down of electrical
power or HVAC serving the Demised Premises, except in the case of an emergency.
Subject to the foregoing sentence and the terms of Section 12.3 below, Landlord
reserves the right to stop service of the elevator, plumbing, heating,
ventilating, air conditioning and electric or other mechanical systems, or
cleaning services, when necessary, by reason of accident or emergency or for
inspection, repairs, alterations, decorations, additions or improvements; which
in the judgement of Landlord are desirable or necessary to be made, until same
shall have been completed, and shall have not responsibility or liability for
failure to supply any of such services in such instance.

       12.3 Interruption of Services. Notwithstanding the terms of this Lease to
the contrary (including, Article 12.2 above and Tenant's self-help remedy
provided for in Article 19.1), if any Building service is interrupted for a
period of two (2) consecutive days due to the negligence or willful acts of
Landlord, its agents, servants, employees, contractors or subcontractors, or for
a period of ten (14) consecutive business days due to any other reason (other
than the misuse, negligence or willful act of Tenant, or Tenants agents,
servants, employees, contractors or subcontractors) and such failure renders the
Demised Premises unusable for Tenant's normal business operations, then there
shall be an abatement of Base Monthly Rent from and after said second or tenth
day, as the case may be, until such services are restored. Landlord agrees to
use all reasonable efforts to restore such services as soon as possible. In the
event that Landlord fails to initiate and diligently prosecute curative actions
within sixteen (16) business hours following receipt by Landlord of written
notice from Tenant of any such service interruption, Tenant shall have the right
to immediately exercise Tenant's self-help rights and remedies pursuant to
Article 19.1 below without providing Landlord with any other or further cure
period.

       12.4 HVAC Improvements. Landlord acknowledges that at the inception of
this Lease the HVAC system in the Building requires upgrade and improvement in
order to provide adequate capacity and quality of heating, ventilating and air
conditioning to the Building and the Demised Premises. In order to satisfy
Landlord's obligation to provide proper services and so as to minimize the
interruption of services, Landlord hereby agrees to perform at its cost and
expense all upgrades to the Building Systems so as to satisfy the standards set
forth in Exhibit H attached hereto. Such upgrades shall be substantially
complete and operating with respect to the Demised Premises prior to the
Commencement Dates for the respective portions of the Demised Premises.

13.    ACCESS TO DEMISED PREMISES

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<PAGE>   74

       13.1 Access to Demised Premises. Subject to the terms of Article 5 with
respect to repairs and Article 12 with respect to services, Tenant shall permit
Landlord to use and maintain pipes and conduits in and through the Demised
Premises; provided, such pipes and conduits are concealed above the ceiling,
beneath the floor or behind the demising walls, and do not interfere with
Tenant's use of the Demised Premises. Landlord and Landlord's agents shall have
the right to enter (with Tenant afforded the opportunity to accompany Landlord
or Landlord's agent) the Demised Premises at reasonable hours upon at least
twenty-four (24) hours advance written notice (except in the case of emergency)
to examine the same and to make such repairs required of Landlord hereunder and
Landlord shall be allowed to take all material into and upon the Demised
Premises that may be required therefor without the same constituting an eviction
of Tenant in whole or in parts provided, any such entry is strictly of a
temporary nature. In the event any such entry by Landlord renders the Demised
Premises unusable for more than two (2) consecutive days, the Base Monthly Rent
shall abate from and after said second day for so long as said entry renders
the Demised Premises unusable. Landlord and Landlord's agents are expressly
granted permission to show the Demised Premises at any reasonable time upon at
least twenty-four (24) hours advance written notice to prospective tenants,
mortgagees, purchasers, lessees of the Building and other persons with a
business interest therein; provided, however, that Landlord shall only exhibit
the Demised Premises to prospective tenants during the final eight (8) months of
Tenant's occupancy of the Demised Premises. Landlord agrees to use reasonable
efforts in connection with any entry to minimize any interference with Tenant's
business operations and to protect Tenant's employees and property within the
Demised Premises, and Tenant shall cooperate with such efforts. Landlord shall
be responsible for any damage to persons or property within the Demised Premises
caused by such entry by Landlord. If Tenant shall not be personally present to
open and permit an entry into the Demised Premises when for emergency reasons an
entry therein shall be necessary, Landlord or Landlords agents may enter the
same by a master key, or may forcibly enter the same, without rendering Landlord
or such agents liable therefor (if during such entry Landlord or Landlord's
agents shall accord reasonable care to Tenant's property), and without in any
manner affecting the obligations, terms, covenants, conditions, provisions or
agreements of this Lease. Nothing herein contained, however, shall be deemed or
construed to impose upon Landlord any obligation, responsibility or liability
whatsoever, for the care, supervision or repair of the Site or the Building or
any part thereof, other than as otherwise provided in this Lease.

14.    INSURANCE

       14.1 Tenant's Insurance. Tenant shall carry at its expense and maintain
in force during the term the following insurance:

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<PAGE>   75

              (1) Commercial General Liability Insurance (including protective
liability coverage on operations of independent contractors engaged in
construction and also blanket contractual liability insurance) on an
"occurrence" basis for the benefit of Tenant and Landlord as additional insured
against claims for "personal injury" liability including without limitation
bodily injury, death or property damage liability with a limit of not less than
$5,000,000.00 in the event of "personal injury" to any number of persons or of
damages to property arising out of any one "occurrence", such insurance may be
furnished under a "primary" policy and an "umbrella" policy, provided that it is
primary insurance and not excess over or contributory with any insurance in
force for Landlord;

              (2) Insurance against loss or damage by fire and such other risks
and hazards as are insurable under present and future standard forms of fire and
extended coverage insurance policies, to the personal property, furniture,
furnishings and fixtures belonging to Tenant located in the Demised Premises for
not less than 100% of the actual replacement value thereof; and

              (3) Such other insurance as may be reasonably required by Landlord
in connection with the Demised Premises or tenant's activities in the Site,
provided such insurance is then carried by owners of comparable Class A
buildings in the San Francisco Bay Area.

       14.2 Policy Requirements. All such insurance shall name Landlord as
additional insured, shall be effected under policies issued by insurers licensed
to do business in the State of California and with general policy holder's
ratings of at least A and financial rating of at least XI, as rated by A.M.
Best's Insurance Reports and shall provide that Landlord shall receive thirty
(30) days' written notice from the insurer prior to any cancellation or change
of coverage.

       14.3 Evidence of Insurance. Tenant shall deliver policies of such
insurance or certificates thereof to Landlord on or before the Commencement
Date, and thereafter at least thirty (30) days before the expiration dates of
expiring policies; and, in the event Tenant shall fail to procure such insurance
or to deliver such policies or certificates, Landlord may, at its option,
procure same for the account of Tenant, and the cost thereof shall be paid to
Landlord as Additional Charges within ten (10) days after delivery to Tenant of
bills therefor.  Nothing contained in this Article 14 shall be construed as a
limitation of Tenant's liability hereunder.

       14.4 Landlord's Insurance. Landlord shall maintain policies of insurance
covering loss of or damage to the Building (including tenant improvements
and subsequent alterations) in the full amount of its replacement cost.  Such
policies shall provide protection (subject to reasonable deductibles) against
all perils

                                      -31-
<PAGE>   76

included within the classification of fire, extended coverage, vandalism,
malicious mischief, special extended perils (all risk), sprinkler leakage, and
any other perils (e.g., flood and earthquake) that Landlord reasonably deems
appropriate; provided, however, that with respect to earthquake insurance
Landlord may not include the cost of earthquake insurance as an Expense unless
the estimated cost of such insurance that would have been payable in the
applicable Base Year is included as an Expense in the Base Year. If Landlord and
Tenant are unable to agree on the estimated cost of earthquake insurance for the
Base Year, Landlord shall designate a qualified insurance broker reasonably
acceptable to Tenant to provide such estimate.

       14.5 Waiver of Subrogation. Notwithstanding any other term or provision
of this Lease to the contrary, Landlord and Tenant hereby both release the
other and their respective employees, agents, servants, licensees and invitees
from and waive any claims either may have against the other or their employees,
agents, servants, licensees or invitees for any loss or damage to the Building,
Demised Premises, improvements on or to the Building, Demised Premises, or to
the contents of the foregoing and any personal property stored or placed thereon
by either of them caused by any of the perils insurable against under fire and
extended coverage insurance policies with "all risk" endorsement, whether such
damage or loss was caused by the negligence of either of them or their
respective employees, agents, servants, invitees or licensees. The foregoing
mutual release and waiver of subrogation shall apply whether or not such
insurance on the Building, Demised Premises, improvements, contents and/or
personal property was in force at the time of the loss or damage. Moreover, each
party agrees to take all actions necessary to make the foregoing release
effective and binding upon their respective insurance carriers so that such
carriers specifically waive any right of subrogation that such carriers might
otherwise have against the other party and/or their respective employees,
agents, servants, invitees or licensees, and Landlord and Tenant shall each
indemnify, the other against and reimburse the other for any and all loss or
expense, including reasonable attorneys' fees, resulting from the failure to
obtain such waiver.

15.    CERTIFICATES OF OCCUPANCY

       15.1 Certificates of Occupancy. Tenant shall not at any time use or
occupy the Demised Premises in violation of the certificates of occupancy issued
for the Building or the Demised Premises and in the event that any department of
the City or County in which the Building is located, or the State of California,
shall hereafter at any time contend or declare that the Demised Premises are
used for a purpose which is in violation of such certificate or certificates of
occupancy, Tenant shall upon five (5) days' notice from Landlord or any
governmental agency, immediately discontinue

                                      -32-
<PAGE>   77

such use of the Demised Premises.  Failure by Tenant to discontinue such use
after such notice shall be considered a default under this Lease and Landlord
shall have the right to terminate this Lease immediately, and in addition
thereto shall have the right to exercise any and all rights and privileges and
remedies given to Landlord by and pursuant to the provisions of Article 18
hereof. Landlord hereby represents and warrants that the Demised Premises may be
used for general office purposes.

16.    SECURITY

       16.1 Security. Tenant, at its expense and otherwise in accordance with
the terms and conditions of Article 4 hereof, may install such additional safety
and security systems or devices, including, without limitation, locked
documentation rooms, tape and disk vaults, smoke detectors, electronic security
devices and auxiliary emergency electric power supplies: provided that, if
Landlord so elects and Tenant approves, any such system must be integrated into
the Building's fire life safety system. Tenant shall have the right by
installation of a key system or otherwise, to control access to the Demised
Premises and access of all elevators to floors wholly occupied by Tenant:
provided that Tenant's use of such system shall not interfere with the other
tenants in the Building or Landlord's obligations to provide services or perform
any work under this Lease, and Tenant shall provide Landlord with keys to such
system. The removal of all such systems and devices at expiration or early
termination of this Lease shall be governed by Article 4 hereof.

17.    BANKRUPTCY

       17.1 Prior to Term. If at any time prior to the date herein fixed as the
Commencement Date for the Initial Premises, there shall be filed by or against
Tenant in any court pursuant to any statute either of the United States or of
any State a petition in bankruptcy or insolvency or for reorganization or for
the appointment of a receiver or trustee or conservator of all or portion of
Tenant's property, or if Tenant makes an assignment for the benefit of
creditors, this Lease shall ipso facto be canceled and terminated and in such
event neither Tenant nor any person claiming through or under Tenant or by
virtue of any statue or by an order of any court shall be entitled TO
possession of the Demised Premises and Landlord, in addition to the other rights
and remedies given by Article 17.3 hereof or by virtue of any, other provision
in this Lease contained or by virtue of any statute or rule of law, may
retain as damages any rent, security, deposit or moneys received by it from
Tenant or others on behalf of Tenant

       17.2 During Term.  If at the date fixed as the Commencement Date
for the Initial Premises or if at any time during the term

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<PAGE>   78

there shall be filed by or against Tenant in any court pursuant to any statute
either of the United States or of any State a petition in bankruptcy or
insolvency or for reorganization or for the appointment of a receiver or trustee
or conservator of all or a portion of Tenant's property, or if Tenant makes an
assignment for the benefit of creditors, and such petition is not released
within ninety (90) days of the date of filing, this Lease, at the option of
Landlord exercised within twenty (20) days following the lapse of such ninety
(90) day period may be canceled and terminated and in such event neither Tenant
nor any person claiming through or under Tenant or by virtue of any statute or
of an order of any court shall be entitled to possession or to remain in
possession of the Demised Premises but shall forthwith quit and surrender the
Demised Premises, and Landlord, in addition to the other rights and remedies
granted by Article 17.3 hereof or by virtue of any other provision in this Lease
contained or by virtue of any statute or rule of law, may retain as damages any
rent, security, deposit or moneys received by it from Tenant or others on behalf
of Tenant.

       17.3 Remedies. In the event of the termination of this Lease pursuant to
Articles 17.1 and 17.2, Landlord shall be entitled to the same rights and
remedies as those set forth in Articles 18.4 and 21 of this Lease.

18.    DEFAULT

       18.1 Tenant's Breach. It shall, at Landlord's option, be deemed a breach
of this Lease if Tenant (a) fails to make any payments of money pursuant to this
Lease ten (10) days following written notice from Landlord of failure to pay
such money, or (b) defaults in fulfilling any other term, covenant, condition,
provision or agreement of this Lease clause (b) continues to exist at after
notice thereof given by Landlord to Tenant (provided, however, that in the case
of any such failure that cannot reasonably be cured within thirty (30) days,
Tenant shall be allowed such additional period as may be reasonably required by
Tenant to cure such default with due diligence, provided Tenant begins to cure
such default within such thirty (30) day period and thereafter diligently and
continuously pursues said cure to completion).

       18.2 Termination Notice. In the event that Landlord elects, pursuant to
Article 18.1, to declare a breach of this Lease, then Landlord shall give Tenant
three (3) days notice of intention to end the term of this Lease and thereupon
at the expiration of said three (3) days, the term of this Lease shall expire as
fully and completely as if that day were the day herein definitely fixed for
expiration of the term hereof, and Tenant shall then quit and surrender the
Demised Premises to Landlord, but Tenant shall remain liable as hereinafter
provided. If Tenant

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<PAGE>   79

fails to so quit and surrender the Demised Premises as aforesaid, Landlord shall
have right, without notice, to re-enter the Demised Premises either by force or
otherwise and dispossess Tenant and the legal representatives of Tenant and all
other occupants of the Demised premises by unlawful detainer or other summary
legal proceedings, and remove their effects and regain possession of the Demised
Premises (but Landlord shall not be obligated to effect the removal) and Tenant
hereby waives service of notice of intention to re-enter or to institute legal
proceedings to that end.

       18.3 Option to Continue Lease. In the event of any breach of this Lease
by Tenant (and regardless of whether or not Tenant has abandoned the Demised
Premises), this Lease shall not terminate unless Landlord, at Landlord's option,
elects at any time when Tenant is in breach of this Lease to terminate Tenant's
right to possession as provided in Article 18.2 or, at Landlord's further
option, by the giving of notice (including but not limited to any notice
preliminary or prerequisite to the bringing of legal proceedings in unlawful
detainer) terminates Tenant's right to possession. For so long as this Lease
continues in effect, Landlord may enforce all of Landlord's rights and remedies
under this Lease, including the right to recover all rent as it becomes due
hereunder. For the purposes of this Article, the following shall not constitute
termination of Tenant's right to possession: (1) acts of maintenance or
preservation or efforts to relet the Demised Premises, or (2) the appointment of
a receiver upon initiative of Landlord to protect Landlord's interest under this
Lease.

       18.4 Damages. In the event of termination of this Lease or termination of
Tenant's right to possession (as a result of Tenant's breach of this Lease or
pursuant to Article 17), Landlord shall have:

              (1) The right to remove any and all persona and property from the
Demised Premises, with legal process, and pursuant to such rights and remedies
as the laws of the State of California shall then provide or permit, but
Landlord shall not be obligated to effect such removal. Said property may, at
Landlord's option, be stored or otherwise dealt with as provided within this
Lease or as such laws may then provide or permit, including but not limited to
the right of Landlord to sell or otherwise dispose of the same or to store the
same, or any part thereof, in a warehouse or elsewhere at the expense or risk of
and for the account of Tenant; provided, however, Landlord, shall provide
written notice to Tenant as required by law prior to effecting the foregoing
action.

              (2) The rights and remedies provided by California Civil Code
Section 1951.2 to recover from Tenant upon termination of the Lease:

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<PAGE>   80

                     (i) The worth at the time of award of the unpaid rent and
       other charges which had been earned at the time of termination;

                     (ii) The worth at the time of award of the amount by which
       the unpaid rent and other charges which would have been earned after
       termination until the time of award exceeds the amount of such rental
       loss that Tenant proves could have been reasonably avoided;

                     (iii) Subject to Subdivision (c) of the California Civil
       Code Section 1951.2, the worth at the time of award of the amount by
       which the unpaid rent and other charges for the balance of the term after
       the time of award exceeds the amount of such rental loss that Tenant
       proves could be reasonably avoided; and

                     (iv) Any other amount necessary to compensate Landlord for
       all the detriment proximately caused by Tenant's failure to perform its
       obligations under this Lease or which in the ordinary course of things
       would be likely to result therefrom. The "worth" at the time of award of
       the amounts referred to in clauses (i) and (ii) of this Article 18.4(2)
       shall be computed by allowing interest at the Default Rate. The worth at
       the time of the award of the amount referred to in clause (iii) of this
       Article 18.4(2) shall be computed by discounting such amount at the
       discount rate of the Federal Reserve Bank of San Francisco at the time of
       award plus one percent

              (3) The rights and remedies provided by California Civil Code
section 1951.4, which allows Landlord to continue this Lease in effect and to
enforce all of its rights and remedies under this Lease, including the right to
recover rent and additional charges as they become due, for as long as
Landlord does not terminate Tenant's right to possession; provided, however, if
Landlord elects to exercise its remedies described in this Article 18.4(3)
and Landlord does not terminate this Lease, and if Tenant requests Landlord's
consent to an assignment of this Lease or a sublease of the Demised Premises
at such time as Tenant is in default, Landlord shall not unreasonably withhold
its consent to such assignment or sublease, subject to the limitations set forth
in Article 3.2.

              (4) To enforce, to the extent permitted by the laws of the
State of California then in force and effect, any other rights or
remedies set forth in this Lease or otherwise applicable hereto by operation
of law or contract.

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<PAGE>   81

       18.5 Landlord's Right to Perform Work. In addition to any other rights
and remedies available to Landlord, if Tenant shall default in the performance
of any obligation on Tenant's part to be performed under this Lease, Landlord
may upon thirty (30) days written notice to Tenant in the case of a
non-emergency, or, in the case of an emergency, without notice, perform the same
for the account of Tenant. If Landlord at any time is compelled to pay or elects
to pay any sum of money or do any act which will require the payment of any sum
of money (including but not limited to employment of attorneys or incurring of
costs), by reason of the failure of Tenant to comply with a term, covenant,
condition, provision or agreement hereof, or, if Landlord is compelled to incur
or elects to incur any expense (including but not limited to reasonable
attorneys' fees in instituting, prosecuting or defending any action or
proceeding, whether or not such action or proceeding proceeds to judgment) by
reason of any default of Tenant hereunder, the sum or sums so paid or incurred
by Landlord with interest at the Default Rate shall be due from Tenant to
Landlord promptly upon demand by Landlord.

19.    LANDLORD'S DEFAULT

       19.1 Landlord's Default. If Landlord shall fail to keep or perform any of
its obligations under this Lease with respect to the making of any payment to
Tenant or the performance of any other obligation of Landlord under this Lease,
and upon the continuance of such failure on Landlord's part for fifteen (15)
days after the receipt by Landlord and any holder of any mortgage or the
beneficiary of any deed of trust secured by the Building ("Mortgagee") of
written notice of such failure from Tenant (provided, however, that in the case
of any such failure which cannot reasonably be cured within fifteen (15) days,
Landlord shall be allowed such additional period as may be reasonably required
by Landlord to cure such failure with due diligence, provided Landlord begins to
cure such default within such fifteen (15) day period and thereafter diligently
and continuously pursues said cure to completion), and without waiving or
releasing Landlord from any obligation, then Tenant may (but shall not be
obligated to), following receipt by Landlord and any Mortgagee of an additional
fifteen (15) day written notice of such continuing failure (a) make such
payment, or Tenant may perform such obligation (but repairs shall be
limited to repairs to the Demised Premises, the Building Systems and the Common
Areas, all of which shall be non-structural) and all sums actually paid or
incurred by Tenant and all necessary and incidental costs and expenses,
including reasonable attorney's fees incurred by Tenant in making such payment
or performing such obligation, together with interest thereon at the
Default Rate, from the date of payment by Tenant, date payment was due to
Tenant or date a cost was incurred by Tenant, shall be paid by Landlord to
Tenant within thirty (30) days after demand, and, if not so paid by
Landlord, Tenant shall have the right to submit its claim to

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<PAGE>   82

binding arbitration pursuant to the American Arbitration Association. In the
event Tenant obtains a favorable decision pursuant to such arbitration and
thereafter Landlord fails to pay the full amount then due, Tenant shall have the
right to offset such sums against any Base Monthly Rent, additional rental or
other amounts thereafter payable by Tenant under this Lease, or (b) Tenant may
pursue any other remedies available to Tenant at law or in equity to collect
payment and/or cause Landlord to cure such default. The foregoing remedies of
Tenant shall be cumulative; but the foregoing right to offset shall be limited
to Autodesk, Inc., to any parent or subsidiary of Autodesk, Inc. to any person,
firm or corporation which shall be controlled by, under the control of, or under
control with Autodesk, Inc., or to any corporation into which Autodesk, Inc. may
be merged, consolidated or which purchases all or substantially all of the
assets of Autodesk, Inc.

20.    NO REPRESENTATIONS BY LANDLORD

       20.1 No Representations. Neither Landlord nor Landlord's agents have made
any representations or promises with respect to the Site, the Building or the
Demised Premises except as herein expressly set forth.

21.    END OF TERM

       21.1 Surrender. Upon the expiration or other termination of the term,
Tenant shall quit and surrender to Landlord the Demised Premises, broom clean,
in as good order, condition and repair as it now is or may hereafter be placed,
ordinary wear and tear and damage by casualty which Tenant is not specifically
obligated to restore hereunder excepted. Tenant shall remove all property of
Tenant. Any property left on the Demised Premises at the expiration or other
termination of this Lease, or after the happening of any of the events of
default set forth in Article 18, may, at the option of Landlord, either be
deemed abandoned or be placed in storage at a public warehouse in the name of
and for the account of and at the expense and risk of Tenant or otherwise
disposed of by Landlord in the manner provided by law. Tenant expressly releases
Landlord of and from any and all claims and liability for damage to or
destruction or loss of property left by Tenant upon the Demised Premises at the
expiration or other termination of this Lease, and Tenant hereby indemnifies
Landlord against any and all claims and liability with respect thereto. If
Tenant holds over after, the term with the express consent of Landlord, such
tenancy shall be from month to month only and shall not be a renewal hereof, and
Tenant shall pay the rent and all the other charges at the same rate as herein
provided and also comply with all of the terms, covenants, conditions,
provisions and agreements of this Lease for the time during which Tenant holds
over. If Tenant holds over after the term without the consent of

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<PAGE>   83

Landlord and shall fail to vacate the Demised Premises after the expiration or
sooner termination of this Lease for any cause or after Tenant's right to occupy
same ceases, thereafter, and notwithstanding anything to the contrary contained
elsewhere in this Lease Tenant shall be liable to Landlord for the use and
occupancy of the Demised Premises in an amount agreed to be 125% of the monthly
installment of Base Monthly Rent, and all the other charges as provided in this
Lease for the last month of the term. Tenant's obligation to observe or perform
all of the terms, covenants, conditions, provisions and agreements of this
Article 21 shall survive the expiration or other termination of this Lease.

22.    QUIET POSSESSION

       22.1 Quiet Possession. Landlord covenants and agrees with Tenant that
upon Tenant's paying Base Monthly Rent and all other charges and observing and
performing all of the terms, covenants, conditions, provisions and agreements of
this Lease on Tenant's part to be observed or performed, Tenant shall have quiet
possession of the Demised Premises for the term subject, however, to the terms
of this Lease and of any ground leases, underlying leases, mortgages and deeds
of trust affecting all or any portion of the Building or any of the areas used
in connection with the operation of the Building.

23.    TERMINATION, NO WAIVER, NO ORAL CHANGE

       23.1 Termination, No Waiver, No Oral Change. In the event that this Lease
terminates for any reason (including but not limited to termination by Landlord)
prior to its natural expiration date, such termination will effect the
termination of any and all agreements for the extension of this Lease (whether
expressed in an option, exercised or not, or collateral document or otherwise);
any right herein contained on the part of Landlord to terminate this Lease shall
continue during any extension hereof; and any option on the part of Tenant
herein contained for an extension hereof shall not be deemed to give Tenant any
option for a further extension beyond the extended term in which the Lease was
terminated. Except as provided by law, an interruption or curtailment of any
services shall not constitute a constructive or partial eviction or except as
provided herein, entitle Tenant to any abatement of rent or any compensation
(including but not limited to compensation for annoyance, inconvenience or
injury to business). No act or thing done by Landlord or Landlord's agents
during the term shall be deemed an acceptance of a surrender of the Demised
Premises, and no agreement to accept such surrender shall be valid unless in
writing signed by Landlord. No employee of Landlord or of  Landlord's agents
shall have any power to accept the keys of said premises prior to the
termination of this Lease. The failure of Landlord to seek redress for
violation of, or to insist upon the strict

                                      -39-
<PAGE>   84

performance of any term, covenant, condition, provision or agreement of this
Lease, or any of the Rules and Regulations attached to this Lease or hereafter
adopted by Landlord, shall not prevent a subsequent act, which would have
originally constituted a violation, from having all the force and effect of an
original violation. The receipt by Landlord of rent with knowledge of the breach
of any term, covenant, condition, provision or agreement of this Lease, shall
not be deemed a waiver of such breach. The failure of Landlord to enforce any of
the Rules and Regulations attached to this Lease, or hereafter adopted, against
Tenant or any other tenant in the Building or in the Site shall not be deemed a
waiver of any such Rule and Regulation. No provision of this Lease shall be
deemed to have been waived by Landlord, unless such waiver be in writing signed
by Landlord. No payment by Tenant or receipt by Landlord of a lesser amount than
the Monthly Installment shall be deemed to be other than on account of the
earliest stipulated rent, nor shall any endorsement or statement on any check or
any letter accompanying any check or payment as rent be deemed an accord and
satisfaction, and Landlord may accept such check or payment without prejudice to
Landlord's right to recover the balance of such rent or pursue any other remedy
in this Lease provided.  This Lease contains the entire agreement between the
parties, and recites the entire consideration given and accepted by the parties.
Any agreement hereafter made shall be ineffective to charge, modify, waive or
discharge it in whole or in part unless such agreement is in writing and signed
by the party against whom enforcement of the change, modification, waiver or
discharge is sought.

24.    WAIVER OF TRIAL BY JURY [INTENTIONALLY DELETED]

25.    INABILITY TO PERFORM

       25.1 Inability to Perform. Except as expressly set forth elsewhere in
this Lease, this Lease and the obligation of Tenant to pay rent and other
payments due hereunder and the obligations of both Landlord and Tenant to keep,
observe and perform all of the other terms, covenants, conditions, provisions
and agreements of this Lease on the part of Tenant and Landlord, as the case may
be, to be kept, observed or performed shall in no way be affected, impaired or
excused because the other party is unable (i) to fulfill any of its obligations
under this Lease, or (ii) to supply, or is delayed or curtailed in supplying,
any service expressly or implied to be supplied, or (iii) to make, or is delayed
or curtailed in making, any repairs, alterations, decorations, additions or
improvements, or (iv) to supply, or is delayed or curtailed in supplying, any
equipment or fixtures, if the other party is prevented, delayed or curtailed
from so doing by reason of any cause beyond its reasonable control including,
but not limited to, acts of God, industry-wide strikes or labor troubles, fuel
or

                                      -40-
<PAGE>   85

energy shortages, governmental preemption or curtailment in connection with a
national emergency or in connection with any rule, order, guideline or
regulation of any department or agency, private or governmental or by reason of
the conditions of supply and demand which have been or are affected by a war or
other emergency. Any such prevention, delay or curtailment shall be deemed
excused and the other party shall not be subject to any liability resulting
therefrom. Tenant waives and releases its right to terminate this Lease under
Section 1932(1) of the California Civil Code or under any similar law or statute
now or hereafter in effect.

26.    BILLS AND NOTICES

       26.1 Bills and Notices. Except as otherwise in the Lease provided, a
bill, statement, consent, or notice of communication which one party may desire
or be required to give to the other party must be in writing and served by
registered or certified mail (postage fully prepaid) or nationally recognized
overnight carrier, addressed to the other party, at the address set forth in
Article J of Section I, or at such other address as the parties shall designate
by notice given as herein provided, and the time of the giving of such notice,
request, demand or communication shall be deemed to be the time when the same is
received or receipt of which is rejected. If Tenant is notified of the identity
and address of Landlord's mortgagee or beneficiary under a deed of trust, or
ground or underlying lessor, Tenant shall give such party notice of any default
by Landlord hereunder by registered or certified mail.

27.    ADDITIONAL CHARGES FOR INCREASED OPERATING EXPENSES AND TAXES

       27.1 Definitions. For purposes of this Article 27, the following terms
shall have the meanings hereinafter set forth:

              (1) "Computation Year" shall mean each twelve (12) consecutive
month period commencing January 1st of each year during the term, provided that
Landlord, upon notice to Tenant, may change the Computation Year from time to
time to any other twelve (12) consecutive month period and, in the event of any
such change, Tenant's Share of Excess Taxes and Expenses (as hereafter defined)
shall be equitably adjusted for the Computation Years involved in any such
charge:

              (2) "Tenant's Share" shall mean the percentage computed by
dividing the Rentable Area of the Demised Premises by the total Rentable Area
of the office space in the Building and, if either the Rentable Area of the
Demised Premises or the total rentable area of the office space in the Building
is changed, Tenant's Share shall be appropriately adjusted so long as such
adjustment does not increase the amounts that Tenant would be

                                      -41-
<PAGE>   86

obligated to pay Landlord in the absence of such adjustment, and, as to the
Computation Year in which such change occurs, for purposes of this Article 27,
Tenant's Share shall be determined on the basis of the number of days during
such Computation Year at each such percentage.

              (3) "Real Estate Taxes" shall mean all taxes, assessments and
charges levied upon or with respect to the Building and the Site (collectively,
the "Real Property") (including any taxes, assessments, or charges levied upon
or charged against Tenant alterations and improvements to the extent not paid by
Tenant pursuant to Article 28) or any personal property of Landlord used in the
operation thereof, or Landlord's interest in the Real Property or such personal
property. Real Estate Taxes shall include, without limitation, all general real
property taxes and general and special assessments, charges, fees or assessments
for transit, housing, day care, open space, art, police, fire or other
governmental services or purported benefits to the Real Property (including,
without limitations, any gross receipts tax or excise tax with respect to the
receipt of such rent), service payments in lieu of taxes, and any tax, fee or
excise on the act of entering into this Lease or any other lease of space in the
Real Property, or on the use or occupancy of the Real Property or any part
thereof, or on the rent payable under any lease or in connection with the
business of renting space in the Real Property, that are now or hereafter levied
or assessed against Landlord by the United States of America, the State of
California, or any political subdivision public corporation, district or other
political or public entity, and shall also include other tax, fee or other
excise, however described, that may be levied or assessed as a substitute for,
or as an addition to, in whole or in part, any other Real Estate Taxes, whether
or not now customary or in the contemplation of the parties on the date of this
Lease. Real Estate Taxes shall not include franchise, transfer, inheritance or
capital stock taxes or income taxes measured by the net income of Landlord from
all sources, unless, due to a change in the method of taxation, any such taxes
is levied or assessed against Landlord as a substitute for, in whole or in part,
any other tax that would otherwise constitute a Real Estate Tax. Real Estate
Taxes shall also include reasonable legal fees, costs and disbursements incurred
in connection with proceedings to contest, determine or reduce Real Estate
Taxes, but only to the extent of such actual reduction obtained and thereafter
realized by Tenant. Notwithstanding the foregoing, Real Estate Taxes shall not
include (i) any taxes payable by Tenant under Article 28 or by other tenants of
the Real Property under similar provisions of their respective leases, or (ii)
any penalties, fines interest or charges attributable to the late payment of any
taxes by Landlord.

              (4) "Applicable Taxes" with respect to any Computation Year shall
mean 100% of the Real Estate Taxes for which bills have been rendered during
such Computation Year.

                                      -42-
<PAGE>   87

Notwithstanding the foregoing, if any Real Estate Tax is levied or assessed
solely with respect to either the office or retail space of the Real Property by
reason of such space being office or retail space, then the term Applicable
Taxes for any Computation Year (i) shall include 100% of the amount of any such
Real Estate Tax that is levied or assessed solely with respect to the office
space of the Real Property, and (ii) shall not include any such Real Estate Tax
that is levied or assessed solely with respect to the retail space of the
complex; provided, however, to the extent Tenant's software business is
considered to be a retail business, Tenant shall be solely responsible for any
Applicable Taxes resulting therefrom. In the event of any changes or alterations
to the Real Property for which the tax statement from the taxing authority does
not allocate assessments, Landlord shall initially make a reasonable
determination of the proper allocation of such assessments based, to the extent
possible, upon records of the assessor and, if not so available, then on an
equitable basis.

              (5) "Expenses" shall mean the total reasonable cost and expenses
paid or incurred by Landlord in connection with the management, operation,
maintenance and repair of the office space and the common areas of the Real
Property, including without limitation, (i) the cost of air conditioning,
electricity, steam, heating, mechanical, ventilating, escalator and elevator
systems and all other utilities and the cost of supplies and equipment and
maintenance and service contracts in connection therewith; (ii) the cost of
non-capital routine, repairs and general maintenance cleaning; (iii) the cost of
fire, extended coverage, boiler, sprinkler, public liability, property damage,
rent, earthquake (but only to the extent included as an Expense in the Base
Year) and other insurance; (iv) wages, salaries and other labor costs, including
taxes, insurance, retirement, medical and other employee benefits for employees
directly engaged in the operation and management of the Building; (v) fees,
charges and other costs, including management fees, consulting fees, legal fees
and accounting fees, of all independent contractors engaged by Landlord or
reasonably charged by Landlord if Landlord performs management services in
connection with the Real Property; (vi) the cost of supplying, replacing and
cleaning employee uniforms; (vii) the fair market rental value of either the
Landlord's or the property manager's offices in the Real Property, such office
not to exceed 700 rentable square feet of space; (viii) the cost, including
rental charges, of any capital improvements made to the Real Property as a
labor-saving device or to effect other economies in the operation or maintenance
of the Real Property, (but only to the extent the savings obtained and
thereafter realized by Tenant), or made to the Real Property after the date of
this lease that are required under any governmental law or regulation that was
not applicable to the Real Property at the time of commencement of the term,
such cost to be amortized over the useful life of such improvement together with
interest on the unamortized balance at the rate of ten percent (10%) per annum
or such higher rate as may

                                      -43-
<PAGE>   88

have been paid by Landlord on funds borrowed for the purpose of constructing
such capital improvements; and (ix) any other expenses of any other kind
whatsoever reasonably incurred in managing, operating, maintaining and repairing
the Real Property. For purposes of computing Tenants Additional Charges pursuant
to this Article 27, Expenses for the Real Property that are not, in Landlord's
reasonable discretion, allocable or chargeable solely to either the office or
retail space of the Real Property shall be allocated between and charged to the
office and retail space of the Real Property on an equitable basis as determined
by Landlord. Notwithstanding anything to the contrary contained, the following
are excluded from Expenses:

                     (A) Any personal property taxes payable by Tenant under
       Article 28 or by other tenants of the Real Property under similar
       provisions in their leases;

                     (B) Repairs or other work occasioned by fire, windstorm or
       other casualty (except for the cost of such repairs or other work that
       relates to the deductible portion of the insurance policy covering such
       casualty) or by the exercise of the right of eminent domain (to the
       extent such cost is a capital improvement, such cost to be amortized over
       the useful life of the improvement);

                     (C) Leasing commissions, accountants or attorneys fees,
       costs and disbursements and other expenses incurred in connection
       with proposals, negotiations or disputes with tenants or other occupants
       or prospective tenants or other occupants;

                     (D) Costs (including permit, license and inspection fees)
       incurred in constructing tenant improvements or decorating, painting or
       redecorating space for tenants or other occupants or vacant rentable
       space;

                     (E) Except to the extent provided in Article 27.1(5)(viii)
       above, costs incurred by Landlord for any alteration, repair, renovation
       or replacement of latent defects, or equipment that is considered a
       capital improvement or replacement under generally accepted accounting
       principles;

                     (F) Except to the extent provided in Article 27.1(5)(viii)
       above, depreciation and amortization;

                     (G) Except to the extent provided in Article 27.1(5)(viii)
       above, interest on debt or

                                      -44-
<PAGE>   89

       amortization payments on any mortgages or deeds of trust or any other
       borrowings;

                     (H) Costs of any capital improvements, repairs or
       replacements, other than such as are specifically included as Expenses in
       Article 27.1(5)(viii) above;

                     (I) Costs incurred in advertising and promotional
       activities for marketing of the Building;

                     (J) The cost of art work for any Common Areas;

                     (K) Landlord's costs of any service sold to any tenant or
       occupant of the Building for which Landlord is entitled to be reimbursed
       as an additional charge or rental over and above the basic rent and
       escalations payable under the Lease or occupancy agreement with that
       tenant or other occupant (including, without limitation, after-hours HVAC
       costs incurred by other tenants or occupants);

                     (L) Costs incurred due to Landlord's violation of any terms
       and conditions of the Lease or any other lease relating to the Building
       or any law, ordinance or governmental rule or regulation affecting the
       Building;

                     (M) Overhead profit increments paid to Landlord's
       subsidiaries or affiliates for management or other services on or to the
       Building or for supplies or other materials to the extent that the cost
       of the services, supplies, or materials exceeds the cost that would have
       been paid had the services, supplies or materials been provided by
       unaffiliated parties on a competitive basis;

                     (N) Any compensation paid to clerks, attendants or other
       persons in commercial concessions operated by Landlord;

                     (O) The cost of completing any punch-list work;

                     (P) The cost of balancing or adjusting the HVAC,
       plumbing or electrical systems in the Building prior to the commencement
       date of this term;

                     (Q) Wages, salaries, fees and fringe benefits paid to
       administrative or executive personnel or officers or partners of
       Landlord;

                                      -45-
<PAGE>   90

                     (R) The cost of correcting defects in the construction of
       the Building or in the equipment located therein;

                     (S) The cost of repairs or replacements arising as a
       consequence of Landlord's failure to maintain an ongoing program of
       regular maintenance, service and repair of any element or component of
       the Building or any Building Systems;

                     (T) The cost of any item of service or repair to the extent
       (i) covered by any warranty, guaranty or insurance policy maintained or
       held by Landlord or (ii) such cost would have been covered by insurance
       proceeds had Landlord maintained the insurance required to be maintained
       by Landlord under this Lease;

                     (U) The costs of tools and equipment used initially in the
       construction, operation, repair and maintenance of the Building;

                     (V) The cost of any work or service performed for or
       facilities furnished to any tenant of the Building to a materially
       greater extent or in a manner more favorable to such tenant than that
       performed for or furnished to Tenant;

                     (W) The cost of overtime or other expense to Landlord in
       curing its defaults or performing work expressly provided in this Lease
       to be borne at Landlord's expense;

                     (X) The monies required to create and/or maintain any
       "reserve" accounts for the maintenance or repair of the Building or site;

                     (Y) The cost of the removal, encapsulation or other
       appropriate remediation of any hazardous materials in the Building; and

                     (Z) Except to the extent provided in Article 27.1(5)
       (viii), any other expense that under generally accepted accounting
       principals would not be considered a normal maintenance or operating
       expense.

              (6) The computation of Expenses shall be made in accordance with
generally accepted accounting principles.

              (7) "Excess Taxes and Expenses" shall mean the amount, if any, by
which the sum of Applicable Taxes and Expenses for any Computation Year exceeds
the sum of Applicable Taxes and

                                      -46-
<PAGE>   91

Expenses for the calendar year 1994 with respect to the Initial Premises and the
Contingent Premises, and otherwise as specifically provided in this Lease ("Base
Year"); provided, however that the component of Excess Taxes and Expenses that
is classified as either Applicable Taxes or Expenses that are within Landlord's
control shall not exceed one hundred and eight percent (108%) of the same
component in the preceding year (for this purpose, items such as costs of
utilities, insurance, real estate taxes and janitorial, to the extent janitorial
is competitively bid, shall be deemed not within Landlord's control).

       27.2 Gross Up For Less Than 95% Occupancy. If occupancy of the Building
during the Base Year or any subsequent year is less than ninety-five percent
(95%), then variable Expenses for the Base Year or such subsequent year shall be
"grossed up" to that amount of Expenses that, using reasonable projections,
would normally be expected to be incurred during the Base Year or such
subsequent year if the Building were ninety-five percent (95%) occupied during
the Base Year or such subsequent year, as determined under generally accepted
accounting principles consistently applied. The term "grossed up" as used in
this Article shall mean and refer to the method of calculating variable Expenses
which is reasonably designed to approximate the cost of providing a variable
Expense service to the rentable areas of the Building which would typically be
receiving such service. The gross-up treatment shall be applied only with
respect to variable Expenses (which are those component expenses of Expenses
that are affected by variations in occupancy levels) arising from services
provided to space in the Building being occupied by tenants in order to
equitably allocate such variable Expenses to the tenants receiving the benefit
thereof; provided, however, that in no event shall such treatment result in any
profit to Landlord. Such treatment shall take into account the degree to which
such expenses would increase if the service in question were being provided to
ninety-five percent (95%) of the rentable area of the Building, as opposed to
the rentable area to which such service was actually provided, and shall also,
take into account the period of time during the Base Year or subsequent year in
question during which the occupancy of the Building was less than ninety-five
percent (95%).

       27.3 Change of Policy. Any costs incurred because of a change of policy
or practice in operating the Building that causes an increase in Expenses over
Expenses incurred in the Base Year, shall be included as Expenses only if the
change in policy or practice would have been made by operators of other Class A
buildings in the San Francisco Bay Area. These changed expenses shall be
included as Expenses to the extent of the increase in cost over the projected
costs that would have been included as Expenses

                                      -47-
<PAGE>   92

in the Base Year had the policy or practice been in effect during the entire
Base Year.

       27.4 Allowances. Expenses shall be reduced by reimbursements, credits,
discounts, reductions, or other allowances received or receivable by Landlord
for items of cost included in Expenses. If Landlord receives a refund of any
portion of the Real Property Taxes that were otherwise included in the Expenses
paid by Tenant, then Landlord shall reimburse Tenant its pro rata share of the
refunded taxes, less any expenses that Landlord reasonably incurred to obtain
the refund.

       27.5 Tenant Payments. (1) Tenant shall pay to Landlord as Additional
Charges one-twelfth (1/12) of Tenant's Share of the Excess Taxes and Expenses
for each Computation Year on or before the first day of each month of such
Computation Year, in advance, in an amount reasonably estimated by Landlord and
billed by Landlord to Tenant. Landlord shall have the right to initially
determine the monthly estimate of Excess Taxes and Expenses and to revise such
estimate from time to time. If Landlord's revision of its estimate of Excess
Taxes and Expenses discloses an underpayment or overpayment by Tenant of
Tenant's Share of Excess Taxes and Expenses then the amount of such underpayment
or overpayment shall be paid by Tenant to Landlord in the next installment of
Rent or Additional Charges under this Lease or, as the case may be, credited
against the next installment of Rent or Additional Charges due from Tenant to
Landlord under this Lease.

              (2) After the expiration of each Computation Year, Landlord shall
furnish Tenant with a statement (herein called "Landlord's Tax and Expense
Statement"), setting forth in reasonable detail the Applicable Taxes and
Expenses for the Computation Year, and Tenant's Share, if any, of Excess Taxes
and Expenses. If Tenant's Share of the actual Excess Taxes and Expenses for such
Computation Year exceeds the total amount thereof (including any adjustment or
credit made pursuant to subparagraph (1) of this Article 27.5) paid by Tenant to
Landlord for such Computation Year, Tenant shall pay to Landlord the difference
between the amount paid by Tenant and Tenant's Share of the actual Excess Taxes
and Expenses within thirty (30) days after the receipt of Landlord's Tax and
Expense Statement, and if the total amount of Tenant's Share, of Excess Taxes
and Expenses (including any adjustment or credit made pursuant to subparagraph
(1) of this Article 27.5) paid by Tenant for any such Computation Year, shall
exceed Tenant's Share of the actual Excess Taxes and Expenses for such
Computation Year, such excess shall be credited against the next
installment of Rent or Additional Charges due from Tenant to Landlord
hereunder.

       27.6 Proration of Computation Year. If the Expiration Date or earlier
date of termination of this Lease shall occur on a date other than the last day
of a Computation Year, Tenant's Share of

                                      -48-
<PAGE>   93

Excess Taxes and Expenses, if any, for the Computation Year in which the
Expiration Date or earlier date of termination occurs shall be in the proportion
that the number of days from and including the first day of the Computation Year
in which the Expiration Date occurs to and including the Expiration Date bears
to 365. Notwithstanding the foregoing, Landlord may, pending the determination
of the amount, if any, of Excess Taxes and Expenses for such partial Computation
Year, furnish Tenant with statements of estimated Excess Taxes and Expenses and
Tenant's Share thereof for such partial Computation Year. Within fifteen (15)
days after receipt of such statements from Landlord, Tenant shall pay as
Additional Charges the amount of Tenant's Share of such Excess Taxes and
Expenses. After such Excess Taxes and Expenses have been finally determined and
Landlord's Tax and Expense Statement has been furnished to Tenant pursuant to
Article 27.5(2) hereof and if there shall have been an underpayment of Tenant's
Share of Excess Taxes and Expenses, Tenant shall remit the amount of such
underpayment to Landlord within thirty (30) days of receipt of such statements,
and if there shall have been an overpayment, Landlord shall remit the amount
of any such overpayment to Tenant within thirty (30) days of the issuance of
such statements.

       27.7 Books and Records. Landlord shall maintain all of its books and
records pertaining to this Lease, the Building, and the Real Property reasonably
necessary for Tenant to substantiate Landlord's Tax and Expense Statement and
all other Additional Charges paid by Tenant pursuant hereto for each calendar
year of this Lease or portion thereof for a period of two (2) years following
the end of each such year. Landlord shall maintain such records on a current
basis, in a manner consistent with the provisions of this Lease and with
generally accepted accounting principles, consistently applied, and in
sufficient detail to facilitate adequate audit and review thereof and, at all
reasonable times, after reasonable notice is given to Landlord, such records
shall be made available to Tenant or its representative for inspection, copying
and audit at the Building. Landlord shall pay to Tenant the amount of any
overpayment made by Tenant as disclosed by such audit, and Tenant shall pay to
Landlord the amount of any underpayment as disclosed by such audit; provided,
however, if such audit by Tenant discloses an overpayment by Tenant of more than
five percent (5%), then in addition to the refund of such overpayment, Landlord
shall reimburse Tenant for the cost of such audit. In the course of any audit
that Tenant may undertake pursuant to Tenant's right to audit set forth herein,
Tenant shall be limited (except for intentional fraud on the part of Landlord)
to recover any overpayment it may have made to Landlord to overpayments made
during the two (2) years prior to the date the audit is completed; and in the
event Landlord discovers that certain Taxes and/or Expenses were not included as
Excess Taxes and Expenses for the calendar year in which such Taxes and/or
Expenses were incurred, Landlord shall only be able to include such Taxes and/or
Expenses as Excess Taxes and Expenses in the two (2)

                                      -49-
<PAGE>   94

subsequent calendar years following the calendar year such Taxes and/or Expenses
were actually incurred.

28.    TAX ON TENANT'S PERSONAL PROPERTY

       28.1 Tax on Tenant's Personal Property. At least ten (10) days prior to
delinquency Tenant shall pay all taxes levied or assessed upon Tenant's
equipment, furniture, fixtures and other personal property (including tenant
alterations and improvements to the extent such tenant alterations and
improvements are personal property) located in or about the premises. If the
assessed value of Landlord's property is increased by the inclusion therein of a
value placed upon Tenant's equipment, furniture, fixtures or other personal
property, Tenant shall pay to Landlord, upon written demand, the taxes so levied
against the Landlord, or the proportion thereof resulting from said increase in
assessment. The portion of real estate taxes payable by Tenant pursuant to this
Article 28.1 and by other tenants of the Real Property pursuant to similar
provisions in their leases shall be excluded from Real Estate Taxes for purposes
of computing the Additional Charges to be paid pursuant to Article 27 hereof.

29.    FOOD, BEVERAGES AND ODORS

       29.1 Food, Beverages and Odors. Tenant shall not operate any "for profit"
restaurant, luncheonette or cafeteria, except with the prior consent of
Landlord, and Tenant shall not cause or permit any odors of cooking or other
processes, or any unusual or objectionable odors to emanate from the Demised
Premises.

30.    SECURITY DEPOSIT

       30.1 Security Deposit. Tenant shall not be required to provide a
security deposit to Landlord.

31.    ARTICLE HEADINGS

       31.1 Article Headings. Article headings and subheadings are inserted
only as a matter  of convenience and for reference and in no way define,
limit or describe the scope or intent of this Lease nor do they in any way
affect this Lease.

32.    DEFINITIONS

       32.1. Definitions.  The term "office,"  or "offices," wherever used in
this Lease, shall not be construed to mean premises used as a store
or stores, for the sale, display or

                                      -50-
<PAGE>   95

storage at any time, of goods, wares or merchandise of any kind, or as a shop,
or for manufacturing. The term "Landlord" as used in this Lease means only the
owner or the mortgagee in possession or grantee in possession under a deed of
trust, or the owner of the Lease of the Building for the time being, so that in
the event of any sale or sales of said land and/or Building or of said Lease, or
in the event of a lease of said land and/or Building, the same Landlord shall be
and hereby is entirely freed and relieved of all covenants and obligations of
Landlord hereunder incurred after the date of such sale; provided, however, the
successor-in-interest to Landlord assumes in writing all of such obligations.
The words "re-enter" and "re-entry" as used in this Lease are not restricted to
their technical legal meaning.

33.    LANDLORD'S APPROVAL

       33.1 Landlord's Approval. The review, approval, inspection or examination
by Landlord on any item to be reviewed, approved, inspected or examined by
Landlord under the terms of this Lease or the Exhibits attached hereto shall not
constitute the assumption of any responsibility by Landlord for either the
accuracy or sufficiency or any such item or the quality or suitability of such
item for its intended use. Any such review, approval, inspection or examination
by Landlord is for the sole purpose of protecting Landlord's interests in the
Building and the Site and under this Lease, and no third employees, visitors or
licensees of Tenant or any such person or entity, shall have any rights
hereunder.

34.    BROKERAGE

       34.1 Brokerage. Tenant represents and warrants that the broker or brokers
specified in Article O of Section I was (were) the sole broker or brokers who
negotiated and brought about the consummation of this Lease, and that no
discussions or negotiations were had with any other broker concerning the
leasing of the Demised Premises. Based on the foregoing representation and
warranty, Landlord has agreed to pay the commissions pursuant to the schedule
attached hereto as Exhibit I. Tenant agrees to indemnity and defend Landlord
against and hold landlord harmless from any claims of brokerage commissions
arising out of any discussions or negotiations allegedly had by Tenant with any
other broker, including without limitation Damner Pike & Company and J.R.
Parrish, inc.

35.    BINDING EFFECT

       35.1 Binding Effect. All of the terms, conditions, provisions and
agreements of this Lease shall  be deemed to be covenants.  The covenants
contained in this Lease shall bind and

                                      -51-
<PAGE>   96

inure to the benefit of Landlord and Tenant and their respective legal
representatives and successors, and, except as otherwise provided in this Lease,
their assigns.

36.    MISCELLANEOUS

       36.1 Offer to Lease.  This Lease is offered to Tenant for signature by
Tenant and this Lease shall not be binding upon Landlord unless and until such
time as Landlord shall have executed and delivered the same.

       36.2 Contractors. Tenant shall not at any time prior to or during the
term hereof, either directly or indirectly, use any contractors, labor or
materials whose use would create any difficulty with other contractors or labor
engaged by Tenant or Landlord or by others the construction, main tenancy or
operation of the Demised Premises or the Building or the Site.

       36.3 Joint and Several Liability.  If a partnership or more than one
legal person is at any time Tenant, (1) each partner and each legal person is
jointly and severally liable for the keeping, observing and performing of all
the terms, conditions, provisions and agreements of this Lease be kept, observed
or performed by Tenant, and (2) the term Tenant as used in this Lease shall
mean and include each of them jointly and severally and the act of or notice
from, or notice of refund to, or the signature of, any one or more of them, with
respect this Lease, including but not limited to, any renewal, extension,
expiration, termination or modification of this Lease, shall be binding upon
each and all of the persons executing this Lease as Tenant with the same force
and effect as if each and all of them had so acted or so given or received such
notice or refund or so signed.

       36.4 California Law. This Lease shall be governed by and construed in
accordance with California law.

       36.5 Partial Invalidity. In the event any term, condition, provision and
agreement herein contained is held to be Invalid or void by any court of
competent jurisdiction, the invalidity of any such term, covenant, provision or
agreement shall in no way affect any other term, covenant, condition provision
or agreement herein contained.

       36.6 Security Patrol. Landlord shall not be obligated to provide or
maintain any security patrol or security system. However, if Landlord elects to
provide such patrol or system, the cost thereof shall be included in
Expenses as defined in Article 27; provided however, Landlord may not include
the costs of such patrol or system as an Expense unless the estimated cost of
such patrol or system that would have been payable in the applicable Base
Year is included as an Expense in the Base Year.  Landlord

                                      -52-
<PAGE>   97

shall not be responsible for the quality of any such patrol or system which may
be provided hereunder or for damage or injury to Tenant, its employees, invitees
or others due to the failure, action or inaction of such patrol or system.

       36.7 Basement Storage. Any basement storage space or other storage space
at any time demised to Tenant hereunder shall be used exclusively for storage.
Notwithstanding any other provisions of this Lease to the contrary, (1) only
such ventilation and heating will be furnished by Landlord as will, in
Landlord's judgment, be adequate for use of said space for storage, (2) no
cleaning, water, heat or air conditioning will be furnished therefor, and (3)
only such electricity will be furnished thereto as will, in Landlord's judgment,
be adequate to light said space as storage space.

       36.8 Time of Essence. Time is of the essence with respect to the
performance of each and every provision of this Lease to be performed by Tenant.

       36.9 No Recordation. Neither this Lease, nor any notice nor memorandum
regarding the terms hereof, shall be recorded by Tenant. Any such unauthorized
recording shall give Landlord the right to declare a breach of this Lease and
pursue the remedies herein. Landlord and Tenant both agree to execute and
acknowledge, at the request of the other party a short form of this Lease in
recordable form.

       36.10 Name Change. If the name of Tenant or any successor or assign
shall be changed during the term of this Lease, such party shall promptly notify
Landlord thereof, which notice shall be accompanied by a certified copy of the
document effecting such change of name.

       36.11 Estoppel Certificates. Upon either party's prior written request
from time to time, the other party shall, within ten (10) business days,
execute, acknowledge and deliver to the requesting party a statement in writing
certifying to those facts for which certification has been requested, including
without limitation (a) that this Lease is unmodified and in full force and
effect (or, if modified, adequately identifying such modification and certifying
that this Lease, as so modified, is in full, force and effect) and (b) the data
to which the Base Monthly Rent, additional payments and other charges are paid
and (c) whether or not there is any default by Landlord or Tenant in the
performance of any term, covenant, condition, provision or agreement contained
in this Lease and further whether or not there are any setoffs, defenses or
counterclaims against enforcement of the obligations to be performed under this
Lease and, it there are, specifying such default, setoff, defense or
counterclaim. Any such statement may be conclusively relied upon
by any prospective purchaser, lessee, assignee or encumbrancer of the
Demised Premises or of all or Any portion of the Building or the Site. A
party's failure to deliver

                                      -53-
<PAGE>   98

such statement within such time shall be deemed a statement that this Lease is
in full force and effect, without modification except as may be represented by
the requesting party.

       36.12 Limited Liability. The liability of Landlord for any default by
Landlord under this Lease or arising in connection with Landlord's operation,
management, leasing, repair, renovation, alteration, or any other matter
relating to the Building, the Common Areas, the Site or the Demised Premises,
shall be limited to the interest of Landlord in the Building, Common Areas and
the Site. Tenant agrees to look solely to Landlord's interest in the Building,
Common Areas and the Site for the recovery of any judgment against Landlord, and
Landlord shall not be personally liable for any such judgment or deficiency
after execution thereon. The limitations of liability contained in this Article
36.12 shall apply equally and inure to the benefit of Landlord, its successors
and their respective present and future partners, of all heirs, beneficiaries,
officers, directors, trustees, shareholders, agents and employees, and their
respective heirs, successors and assigns.

       36.13 Common Area Rights. The rights of Tenant hereunder in and to the
Common Areas shall at all times be subject to the rights of Landlord and other
tenants of Landlord who use the same in common with Tenant, and it shall be the
duty of Tenant to keep all of the Common Areas free and clear of any
obstructions created or permitted by Tenant or resulting from Tenant's operation
and to permit the use of any of the Common Areas only for normal parking and
ingress and egress by the invitees of Tenant and from the Building. If, in the
opinion of Landlord, authorized persons are using the Common Areas by reason of
the presence of Tenant in the Demised Premises, Tenant, upon demand of Landlord,
shall correct such situation by appropriate action or proceedings against all
such unauthorized persons. Nothing herein shall affect the right of Landlord at
any time to remove any such unauthorized persons from said areas or to prevent
the use of any of said areas by unauthorized persons.

       36.14 Governmental Regulation. If, as a result of any governmental rule
or regulation, Landlord imposes a curtailment of services or equipment in Site,
the Demised Premises or the Building, Tenant shall comply therewith and shall be
liable to Landlord for any surcharge imposed for any violation by Tenant.

       36.15 Due Authorization. Each of the persons executing this Lease
on behalf of Landlord and Tenant warrants that Landlord or Tenant, as the case
may be, is a duly authorized and existing corporation, that it has been and
is qualified to do business in California, that it has full right and
authority to enter into this Lease, and that each of the persons signing on
behalf of Landlord and Tenant, as the case may be, were authorized to do
so. Each party shall provide the other party with satisfactory evidence of
such authority upon request.

                                      -54-
<PAGE>   99

       36.16 Dispute Resolution. In the event that either Landlord or Tenant
fails to perform any of its obligations under this Lease or in the event a
dispute arises concerning the meaning or interpretation of any provisions of
this Lease, the basis of the dispute shall be settled by judicial proceedings
and the defaulting party or the party not prevailing in such dispute, as the
case may be, shall pay any and all costs and expenses incurred by the other
party in enforcing or establishing its rights hereunder, including without
limitation, court costs and attorneys fees.

       36.17 Exhibits. Any rider or exhibit annexed hereto is made a part
hereof.

37.    SIGNAGE

37.1 Signage. So long as Tenant leases and occupies least 95,387 rentable square
feet in the Building, Tenant shall have the exclusive right for all exterior
signage on the Building except for a general sign identifying "Marin Executive
Center." Tenant's signage on the Building shall not cover or be larger than
Landlord's general sign. If Tenant's signage on the Building predates Landlord's
signage, Landlord shall not retroactively require Tenant to reduce the size of
Tenant's Building signage. Subject to the rights of any existing tenants of the
Building, Tenant shall have the non-exclusive right to have its name included in
the existing monument sign at the entry drive, which signage shall be restricted
to new tenants of at least 1,000 rentable square feet and shall be listed in
descending order from top to bottom based on rentable square feet leased. In
addition, upon occupancy of the Initial Premises, Tenant shall have the non
exclusive right together with tenants occupying at least 10,000 rentable square
feet to install a monument sign on the hill directly below the Building facing
Highway 101 (the "Hill Sign"). So long as Tenant either (i) occupies the Initial
Premises and continues to exercise any and all Expansion Options when and as
they all arise, or (ii) occupies at least 95,387 rentable square feet in the
Building, the right to display a Hill Sign shall be exclusive to Tenant.
Tenant's Hill Sign may be lighted, provided such lighting is continuous
(non-flashing).  To the extent applicable, such signage shall be subject to the
prior approval of the City of San Rafael and the Landlord, and in the case of
the Landlord, such approval shall not be unreasonably withheld, delayed, or
conditioned.

38.    HAZARDOUS MATERIALS

       38.1 Tenant Compliance. Tenant shall, at its sole cost and expense,
comply with all federal, state or local laws from time to time in effect
("Hazardous Materials Laws") concerning the management, use, generation,
storage, transportation, presence,

                                      -55-
<PAGE>   100

discharge or disposal of hazardous, toxic, radioactive or carcinogenic
materials, substances or wastes ("Hazardous Materials"). Tenant shall cause any
and all Hazardous Materials brought onto or used, generated, stored or
discharged by Tenant's improvement, alteration or use of the Demised Premises,
to be removed from the Demised Premises, and transported for disposal in
accordance with applicable Hazardous Materials Laws. Landlord shall have the
right to enter the Demised Premises from time to time to conduct tests,
inspections and surveys, concerning Hazardous Materials and to monitor Tenant's
compliance with its obligations concerning Hazardous Materials and Hazardous
Materials laws. Tenant shall immediately notify Landlord in writing of any
voluntary cleanup or removal action instituted or proposed by Tenant, any
enforcement, cleanup, removal or other governmental or regulatory action
instituted or threatened, or any claim made or threatened by any person against
Tenant, the Demised Premises, or the Site relating to any Hazardous Materials or
any Hazardous Materials Laws. Tenant shall also supply to Landlord as promptly
as possible, and in any event within five (5) business days after Tenant first
receives or sends the same, copies of all claims, reports, complaints, notices,
warnings or asserted violations relating in any way to the Demised Premises or
Tenant's use thereof and concerning Hazardous Materials or Hazardous Materials
Laws. Tenant shall not negotiate or enter into any settlement agreement, consent
decree or other compromise in respect of Hazardous Materials or Hazardous
Materials Laws affecting the Demised Premises or the Site except after giving
Landlord prior written notice and a full and fair opportunity to appear,
intervene or otherwise assert and protect Landlord's rights and interests.

       38.2 Landlord's Representations. To the best of Landlord's knowledge, the
Demised Premises, Building and Site are not in violation of any Hazardous
materials laws. Neither Landlord nor, to Landlord's best knowledge, any third
party has used, generated, manufactured, produced, stored, released or disposed
of, on, under, above or about the Demised Premises, Building or Site any
Hazardous Materials except immaterial amounts of residual office, cleaning
and building supplies maintained to commercially reasonable standards, emissions
and discharges from regular vehicular traffic, those used in ordinary
landscaping operations occasioned by the use and occupancy of the Demised
Premises, Building and Site, materials which do not, as of the date of this
lease, violate any applicable Hazardous Materials Laws, and which are either
incorporated into the structure of the building as useful building
components, or otherwise handled, stored, or used in compliance with all
applicable laws.  There is no pending or, to Landlord's best knowledge,
threatened proceeding or inquiry by any governmental authority with respect to
the presence of Hazardous Materials on the Demised Premises, Building and
Site, or the migration thereof from or to the other property.  To the best of
Landlord's knowledge there is and has never been any above or below

                                      -56-
<PAGE>   101

ground storage tanks or tanks on, under, or above, or about the Demised
Promises, Building or Site.

       IN WITNESS WHEREOF, Landlord and Tenant has respectively executed this
Lease as of the day and year first above written.

<TABLE>
<CAPTION>
LANDLORD:                                    TENANT:
---------                                    -------
<S>                                          <C>
CONNECTICUT GENERAL LIFE                     AUTODESK, INC.,
INSURANCE COMPANY, a Connecticut             a California corporation
corporation, by its authorized
agent, CIGNA INVESTMENTS, INC.,
a Connecticut corporation
</TABLE>
                                             By:  /s/ ERIC HERR
                                                --------------------------------
                                             Its:
By:  /s/ JOSEPH W. SPRINGMAN                     -------------------------------
   -----------------------------------
Its: /s/ MANAGING DIRECTOR
    ----------------------------------

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