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                                  EXHIBIT 10.1

                       VERTEX PHARMACEUTICALS INCORPORATED

                             1991 STOCK OPTION PLAN

                As amended and restated as of September 14, 1999

         1.       PURPOSE OF PLAN.

         The purpose of this 1991 Stock Option Plan (the "Plan") is to promote
the interests of Vertex Pharmaceuticals Incorporated, a Massachusetts
corporation (the "Company," including for the purposes of this paragraph any
affiliated companies), by providing a method whereby employees of the Company,
and others providing material assistance to the Company, may be given
compensation or additional compensation for their efforts on behalf of or
assistance to the Company, and to aid the Company in attracting and retaining
capable personnel.

         2. SCOPE AND DURATION OF THE PLAN.

         Options granted under this Plan may contain such terms as will qualify
the options as incentive stock options ("ISOs") within the meaning of Section
422(b) of the Internal Revenue Code of 1986, as amended (the "Code"), or in the
form of non-statutory stock options ("NSOs"). Unless otherwise indicated,
references in this Plan to "options" include ISOs and NSOs. Subject to
adjustment as provided in Section 11 hereof, the maximum number and kind of
shares of the Company's capital stock with respect to which options may be
granted under this Plan shall be 2,000,000 shares of Common Stock, $.01 par
value per share ("Common Stock"). Until termination of this Plan, the Company
shall at all times reserve a sufficient number of shares to meet the
requirements of the Plan. Such shares may be authorized and unissued shares or
shares held in the Company's treasury.

         There shall become available for subsequent grants under this Plan any
shares of Common Stock underlying an option which cease for any reason to be
subject to purchase under such option. No ISO shall be granted under this Plan
more than 10 years after adoption of the Plan by the Board of Directors.

         3.       ADMINISTRATION OF PLAN.

         The Compensation Committee or any successor thereto (the "Committee")
appointed by the Company's Board of Directors shall administer this Plan. The
Committee shall have full power and authority to: (i) designate the employees
and other persons to whom options shall be granted; (ii) designate options or
any portion thereof as ISOs; (iii) determine the number of shares of Common
Stock for which options may be granted and the option price or prices; (iv)
determine the other terms and provisions of option agreements (which need not be
identical) including, but not limited to, provisions concerning the time or
times when and the extent to which the options may be exercised and the nature
and duration of restrictions as to transferability or constituting substantial
risks of forfeiture, provided that with respect to ISOs such time or times shall
not occur before approval of this Plan by the stockholders of the Company in the
manner provided under Section 15 below; (v) amend or modify any option, with the
consent of the holder thereof; (vi) accelerate the right of an optionee to
exercise in whole or in part any previously granted option; and (vii) interpret
the provisions and supervise the administration of this Plan.

         Options may be granted singly or in combination. The Committee shall
have the authority to grant in its discretion to the holder of an outstanding
option in exchange for the surrender and

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cancellation of such option, a new option in the same or a different form and
containing such terms as the Committee may deem appropriate, including without
limitation a price which is different (either higher or lower) than any price
provided in the option so surrendered and cancelled.

         In connection with the grant of an NSO, the Committee may in its
discretion, concurrently or after grant of the NSO, grant or agree to grant a
tax offset bonus to the optionee to offset in whole or in part the tax liability
of the optionee realized upon exercise of the NSO.

         All decisions and selections made by the Committee pursuant to the
provisions of this Plan shall be made by a majority of its members. Any decision
reduced to writing and signed by all of the members of the Committee who are
authorized to make such decision shall be as fully effective as if it had been
made by a majority at a duly held meeting of the Committee.

         The Committee may employ attorneys, consultants, accountants or other
persons, and the Committee, the Company and its officers and directors shall be
entitled to rely upon the advice, opinions or valuations of such persons. All
actions taken and all interpretations and determinations made by the Committee
in good faith shall be final and binding upon the Company, all persons who
receive grants of options, and all other interested persons. No member or agent
of the Committee shall be personally liable for any action, determination, or
interpretation made in good faith with respect to this Plan or grants hereunder.
Each member of the Committee shall be indemnified and held harmless by the
Company against any cost or expense (including counsel fees) reasonably incurred
by such member or liability (including any sum paid in settlement of a claim
with the approval of the Company) arising out of any act or omission to act in
connection with this Plan unless arising out of such member's own fraud or bad
faith. Such indemnification shall be in addition to any rights of
indemnification the members of the Committee may have as directors or otherwise
under the by-laws of the Company, or any agreement, vote of stockholders or
disinterested directors, or otherwise.

         4.       DESIGNATION OF PARTICIPANTS.

         Options may be granted only to employees, including officers who are
employees, of the Company or any parent or subsidiary of the Company, and other
individuals, including consultants, who are determined by the Committee to
contribute, or have the potential to contribute, materially to the success of
the Company or any parent or subsidiary, provided that ISOs shall be granted
only to persons who are employees of the Company or any parent or subsidiary of
the Company.

         5.       OPTION PRICE.

         (a) The purchase price of each share of Common Stock subject to an
option or any portion thereof which has been designated as an ISO shall not be
less than 100% (or 110%, if at the time of grant the optionee owns or under
Section 424(d) of the Code is deemed to own more than 10% of the total combined
voting power of all classes of stock of the Company or any parent or subsidiary
corporation) of the fair market value of such share on the date the option is
granted, determined without regard to any restriction other than a restriction
which, by its terms, will never lapse. The purchase price of each share of
Common Stock subject to an NSO shall be such price as the Committee shall
determine in its sole discretion.

         (b) The fair market value of a share of Common Stock on a particular
date shall be the mean between the highest and lowest quoted selling prices on
such date (the "valuation date") on the securities market where the Common Stock
of the Company is traded, or if there were no sales on the valuation date, on
the next preceding date within a reasonable period (as determined in the sole
discretion of the Committee) on which there were sales. In the event that there
were no sales

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in such a market within a reasonable period, the fair market value shall be as
determined in good faith by the Board of Directors in its sole discretion.

         6.       TERM AND EXERCISE OF OPTIONS.

         (a) The term of each ISO granted under this Plan shall be not more than
ten years from the date of grant, or five years from the date of grant if at the
time of grant the optionee owns (or under Section 424(d) of the Code is deemed
to own) more than 10% of the total combined voting power of all classes of stock
of the Company or any parent or subsidiary corporation. The term of each NSO
granted under this Plan shall be such period of time as the Committee shall
determine in its sole discretion.

         (b) An option shall be exercisable at such time or times as shall be
determined by the Committee. An option may be exercised only by written notice
of intent to exercise such option with respect to a specified number of shares
of Common Stock and payment to the Company of the amount of the option price for
the number of shares of Common Stock as to which such notice applies. Payment
for such shares shall be paid at the time of purchase (i) in cash, (ii) with
shares of Common Stock that have been held for at least six months, to be valued
at the fair market value thereof on the date of such exercise, determined as
provided in Section 5(b), (iii) by any other means, including the promissory
note of the holder of the option, which the Committee determines to be
consistent with the purpose of this Plan and applicable law, or (iv) a
combination of the foregoing. Upon receipt of payment, the Company shall deliver
to the person exercising such option a certificate or certificates for such
shares. It shall be a condition of the Company's obligation to issue Common
Stock upon exercise of an option that the person exercising the option pay, or
make provision satisfactory to the Company for the payment of, any taxes which
the Company is obligated to collect with respect to the transfer of Common Stock
upon such exercise or (in the case of an ISO) with respect to the disposition of
such Common Stock.

         The Committee may establish a program through which optionees can
borrow funds with which to purchase Common Stock pursuant to exercise of an
option.

         (c) The proceeds of the sale of Common Stock subject to options are to
be added to the general funds of the Company and used for its general corporate
purposes.

         7.       INCENTIVE STOCK OPTIONS. [Intentionally omitted.]

         8.       TRANSFER OF OPTIONS.

         An option or portion thereof designated as an ISO shall not be
transferable by an optionee otherwise than by will or the laws of descent and
distribution, and shall be exercisable during his lifetime only by him. An NSO
shall not be transferable by an optionee otherwise than by will or the laws of
descent and distribution, or pursuant to a qualified domestic relations order as
defined by the Code or Title I of the Employee Retirement Income Security Act or
the rules thereunder, except as otherwise provided by the Committee.
Notwithstanding the foregoing, the designation of a beneficiary of an option by
an optionee shall not be deemed a transfer prohibited by this Section.

         9.       TERMINATION OF EMPLOYMENT.

         (a) If the employment of an optionee terminates for any reason other
than for cause or by reason of death, or disability (as may be determined by the
Committee under Section 9(c) below), the optionee may for a period of three
months after the date of termination of employment (unless a longer period is
allowed by the Committee) exercise options held by the optionee to the extent he
or she was entitled to exercise such options on the date when his or her
employment

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terminated. In no event, however, may such optionee exercise an option at a time
when the option would not be exercisable had the optionee remained an employee.
For purposes of this Section 9, an optionee's employment will not be considered
terminated (i) if the Committee in the exercise of its discretion shall so
determine in the case of sick leave or other bona fide leave of absence approved
by the Company or any parent or subsidiary company or (ii) in the case of a
transfer by such optionee to the employment of an affiliated company of the
employing company.

         (b) If an optionee dies at a time when he or she is entitled to
exercise an option, then at any time or times within one year after death,
such option may be exercised, as to all or any of the shares which the
optionee was entitled to purchase immediately prior to his death, by the
optionee's executor or administrator or the person or persons to whom the
option is transferred by will or the applicable laws of descent and
distribution. In no event, however, may any option be exercised after the
expiration of such option by its terms, except as the Committee may otherwise
allow for a period up to one year after such optionee's death.

         (c) If an optionee becomes disabled at a time when he or she is
entitled to exercise an option, then at any time or times within one year after
the date of such disability, he or she may exercise such option as to all or any
of the shares which he or she was entitled to purchase under such option
immediately prior to his or her disability. In no event, however, may any option
be exercised after the expiration of such option by its terms. The Committee
shall have authority to determine whether or not an optionee has become disabled
(as such term may be used in the Code); and its determination shall be binding
on all concerned.

         (d) If termination of employment of an optionee shall be for cause or
in violation of an agreement by the optionee to remain in the employ of the
Company or any parent or subsidiary company, the options held by such optionee
shall terminate forthwith. If an optionee shall breach in a material respect an
agreement to refrain from competition with the Company or any parent or
subsidiary company, or to refrain from solicitation of the Company's customers,
suppliers or employees of the Company or any parent or subsidiary company, the
options, and any shares of Common Stock issued pursuant to the exercise of
options, held by such optionee shall at the option of the Company be forfeited
by the optionee and deemed not to be outstanding.

         10.      RIGHTS OF STOCKHOLDERS.

         The holders of options shall not be or have any of the rights or
privileges of stockholders of the Company in respect of any shares of Common
Stock purchasable upon the exercise of any option until such option shall have
been validly exercised.

         11.      ADJUSTMENTS.

         Notwithstanding any other provision of this Plan, the Committee may at
any time make or provide for such adjustments to this Plan, to the number and
class of shares available hereunder or to any outstanding options, as it shall
deem appropriate to prevent dilution or enlargement of rights, including
adjustments in the event of distributions to holders of Common Stock of other
than a normal cash dividend, changes in the outstanding Common Stock by reason
of stock dividends, split-ups, recapitalizations, mergers, consolidations,
combinations or exchanges of shares, separations, reorganizations, liquidations
and the like. In the event of any general offer to holders of Common Stock
relating to the acquisition of their shares, the Committee may make such
adjustment as it deems equitable in respect of outstanding options, including in
the Committee's discretion revision of outstanding options, so that they may be
exercisable for the consideration payable in the acquisition transaction. Any
such determination by the Committee shall be conclusive.

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         12.      AMENDMENTS OR TERMINATION.

         The Company's Board of Directors or the Committee may amend, alter, or
discontinue this Plan, except that no amendment or alteration requiring
stockholder approval pursuant to the Code's provisions with respect to ISOs
shall be made without the approval of the Company's stockholders.

         13.      FOREIGN NATIONALS.

         The Committee may in order to fulfill the purposes of this Plan modify
grants to participants who are foreign nationals or employed outside the United
States to accommodate differences in applicable law, tax policy, or custom.

         14.      GOVERNING LAW.

         This Plan shall be governed by and construed and enforced in accordance
with the laws of the Commonwealth of Massachusetts to the extent that such laws,
as applicable to the Plan, are not superseded by or inconsistent with Federal
law.

         15.      EFFECTIVE DATE.

         This Plan is effective as of May 24, 1991, the date of its adoption by
the Company's Board of Directors and Shareholders.

         16. CONSOLIDATIONS OR MERGERS. In the event of a consolidation or
merger in which the Company is not the surviving corporation or which results in
the acquisition of substantially all the Company's outstanding stock by a single
person or entity or by a group of persons and/or entities acting in concert, or
in the event of the sale or transfer of substantially all the Company's assets
(any of the foregoing, an "Acquisition"), all then outstanding Options shall
terminate unless assumed pursuant to clause (i) below; provided, that either (i)
the Committee shall provide for the surviving or acquiring entity or an
affiliate thereof to assume the outstanding Options or grant replacement options
in lieu thereof, any such replacement to be upon an equitable basis as
determined by the Committee, or (ii) if there is no such assumption or
substitution, all outstanding Options shall become immediately and fully
exercisable immediately prior to the Acquisition, notwithstanding any
restrictions or vesting conditions set forth therein.

rev.11/18/99/SPC

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                                  EXHIBIT 10.2

                       VERTEX PHARMACEUTICALS INCORPORATED

                           1994 STOCK AND OPTION PLAN

               (as amended as of September 14, 1999 and restated)

1.     DEFINITIONS

       Unless otherwise specified or unless the context otherwise requires, the
following terms, as used in this Vertex Pharmaceuticals Incorporated 1994 Stock
and Option Plan, have the following meanings:

AFFILIATE means a corporation which, for purposes of Section 424 of the Code, is
a parent or subsidiary of the Company, direct or indirect.

BOARD OF DIRECTORS means the Board of Directors of the Company.

CODE means the United States Internal Revenue Code of 1986, as amended.

COMMITTEE means the Compensation Committee of the Board of Directors or any
successor thereto appointed by the Board of Directors pursuant to Section 4
hereof to administer this Plan.

COMMON STOCK means shares of the Company's common stock, $.01 par value.

COMPANY means Vertex Pharmaceuticals Incorporated, a Massachusetts corporation.

DISABILITY or DISABLED means permanent and total disability as defined in
Section 22(e)(3) of the Code.

EXCHANGE ACT means the Securities Exchange Act of 1934, as amended.

FAIR MARKET VALUE of a Share of Common Stock on a particular date shall be the
mean between the highest and lowest quoted selling prices on such date (the
"valuation date") on the securities market where the Common Stock of the Company
is traded, or if there were no sales on the valuation date, on the next
preceding date within a reasonable period (as determined in the sole discretion
of the Committee) on which there were sales. In the event that there were no
sales in such a market within a reasonable period, the fair market value shall
be as determined in good faith by the Committee in its sole discretion. The Fair
Market Value as determined in this paragraph shall be rounded down to the next
lower whole cent if the foregoing calculation results in a number including
fractional cents.

ISO means an option intended to qualify as an incentive stock option under Code
Section 422(b).

KEY EMPLOYEE means an employee of the Company or of an Affiliate (including,
without limitation, an employee who is also serving as an officer or director of
the Company or of an Affiliate), designated by the Committee to be eligible to
be granted one or more Stock Rights under the Plan.

NQSO means an option which is not intended to qualify as an ISO.

NON-EMPLOYEE DIRECTOR means a member of the Board of Directors who is not an
employee of the Company or any Affiliate.

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OPTION means an ISO or NQSO granted under the Plan.

PARTICIPANT means a Key Employee, Non-Employee Director, consultant or
advisor of the Company to whom one or more Stock Rights are granted under the
Plan. As used herein, "Participant" shall include "Participant's Survivors"
and a Participant's permitted transferees where the context requires.

PARTICIPANT'S SURVIVORS means a deceased Participant's legal representatives
and/or any person or persons who acquires the Participant's rights to a Stock
Right by will or by the laws of descent or distribution.

PLAN means this Vertex Pharmaceuticals Incorporated 1994 Stock and Option Plan,
as amended from time to time.

SHARES means shares of the Common Stock as to which Stock Rights have been or
may be granted under the Plan or any shares of capital stock into which the
Shares are changed or for which they are exchanged within the provisions of
Section 3 of the Plan. The Shares issued upon exercise of Stock Rights granted
under the Plan may be authorized and unissued shares or shares held by the
Company in its treasury, or both.

STOCK AGREEMENT means an agreement between the Company and a Participant
executed and delivered pursuant to the Plan, in such form as the Committee shall
approve.

STOCK AWARD means an award of Shares or the opportunity to make a direct
purchase of Shares of the Company granted under the Plan.

STOCK RIGHT means a right to Shares of the Company granted pursuant to the Plan
as an ISO, an NQSO or a Stock Award.

2.     PURPOSES OF THE PLAN

       The Plan is intended to encourage ownership of Shares by Key Employees,
Non-Employee Directors and certain consultants and advisors to the Company in
order to attract such persons, to induce them to work for the benefit of the
Company or of an Affiliate and to provide additional incentive for them to
promote the success of the Company or of an Affiliate. The Plan provides for the
granting of Stock Rights to Key Employees, Non-Employee Directors, consultants
and advisors of the Company.

3.     SHARES SUBJECT TO THE PLAN

       The number of Shares subject to this Plan as to which Stock Rights may be
granted from time to time shall be 2,000,000 plus the number of shares of Common
Stock previously reserved for the granting of options under the Vertex
Pharmaceuticals Incorporated 1991 Stock Option Plan but not granted thereunder,
or the equivalent of such number of Shares after the Committee, in its sole
discretion, has interpreted the effect of any stock split, stock dividend,
combination, recapitalization or similar transaction in accordance with Section
17 of this Plan.

       If an Option granted hereunder or any option granted under the 1991 Stock
Option Plan ceases to be "outstanding", in whole or in part, or if the Company
shall reacquire any Shares issued pursuant to Stock Awards, the Shares which
were subject to such Option and any Shares so reacquired by the Company shall
also be available for the granting of other Stock Rights under the Plan. Any
Stock Right shall be treated as "outstanding" until such Stock Right is
exercised in full,

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or terminates or expires under the provisions of the Plan, or by agreement of
the parties to the pertinent Stock Agreement, without having been exercised in
full.

4.     ADMINISTRATION OF THE PLAN

       The Plan shall be administered by the Committee.

       Subject to the provisions of the Plan, the Committee is authorized to:

     a.  Interpret the provisions of the Plan or of any Option, Stock Award or
         Stock Agreement and to make all rules and determinations which it deems
         necessary or advisable for the administration of the Plan;

     b.  Determine which employees of the Company or of an Affiliate shall be
         designated as Key Employees and which of the Key Employees,
         Non-Employee Directors, consultants and advisors of the Company and its
         Affiliates shall be granted Stock Rights;

     c.  Determine the number of Shares and exercise price for which a Stock
         Right or Stock Rights shall be granted;

     d.  Specify the terms and conditions upon which a Stock Right or Stock
         Rights may be granted; and

     e.  In its discretion, accelerate the date of exercise of any installment
         of any Stock Right; provided that the Committee shall not, without the
         consent of the Option holder, accelerate the exercise date of any
         installment of any Option granted to any Key Employee as an ISO (and
         not previously converted into an NQSO pursuant to Section 20) if such
         acceleration would violate the annual vesting limitation contained in
         Section 422(d) of the Code, as described in Section 6.2.3.

provided, however, that all such interpretations, rules, determinations, terms
and conditions shall be made and prescribed in the context of preserving the tax
status under Code Section 422 of those Options which are designated as ISOs and
shall be in compliance with any applicable provisions of Rule 16b-3 under the
Exchange Act. Subject to the foregoing, the interpretation and construction by
the Committee of any provisions of the Plan or of any Stock Right granted under
it shall be final.

         The Committee may employ attorneys, consultants, accountants or other
persons, and the Committee, the Company and its officers and directors shall be
entitled to rely upon the advice, opinions or valuations of such persons. All
actions taken and all interpretations and determinations made by the Committee
in good faith shall be final and binding upon the Company, all Participants, and
all other interested persons. No member or agent of the Committee shall be
personally liable for any action, determination, or interpretation made in good
faith with respect to this Plan or grants hereunder. Each member of the
Committee shall be indemnified and held harmless by the Company against any cost
or expense (including counsel fees) reasonably incurred by him or liability
(including any sum paid in settlement of a claim with the approval of the
Company) arising out of any act or omission to act in connection with this Plan
unless arising out of such member's own fraud or bad faith. Such indemnification
shall be in addition to any rights of indemnification the members of the
Committee may have as directors or otherwise under the by-laws of the Company,
or any agreement, vote of stockholders or disinterested directors, or otherwise.

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5.     ELIGIBILITY FOR PARTICIPATION

       The Committee shall, in its sole discretion, name the Participants in the
Plan, provided, however, that each Participant must be a Key Employee,
Non-Employee Director, consultant or advisor of the Company or of an Affiliate
at the time a Stock Right is granted. Notwithstanding the foregoing, the
Committee may authorize the grant of a Stock Right to a person not then an
employee, Non-Employee Director, consultant or advisor of the Company or of an
Affiliate; PROVIDED, HOWEVER, that the actual grant of such Stock Right shall be
conditioned upon such person becoming eligible to become a Participant at or
prior to the time of execution of the Stock Agreement evidencing such Stock
Right. The granting of any Stock Right to any individual shall neither entitle
that individual to, nor disqualify him or her from, participation in other
grants of Stock Rights.

6.     TERMS AND CONDITIONS OF OPTIONS

       6.1 GENERAL. Each Option shall be set forth in writing in a Stock
Agreement, duly executed by the Company and, to the extent required by law or
requested by the Company, by the Participant. The Committee may provide that
Options be granted subject to such conditions as the Committee may deem
appropriate including, without limitation, subsequent approval by the
shareholders of the Company of this Plan or any amendments thereto, PROVIDED,
HOWEVER, that the option price per share of the Shares covered by each Option
shall not be less than the par value per share of the Common Stock. Each Stock
Agreement shall state the number of Shares to which it pertains, the date or
dates on which it first is exercisable and the date after which it may no longer
be exercised. Option rights may accrue or become exercisable in installments
over a period of time, or upon the achievement of certain conditions or the
attainment of stated goals or events. Exercise of any Option may be conditioned
upon the Participant's execution of a Share purchase agreement in form
satisfactory to the Committee providing for certain protections for the Company
and its other shareholders, including requirements that the Participant's or the
Participant's Survivors' right to sell or transfer the Shares may be restricted,
and the Participant or the Participant's Survivors may be required to execute
letters of investment intent and to acknowledge that the Shares will bear
legends noting any applicable restrictions.

       6.2 ISOS. ISOs shall be issued only to Key Employees. In addition to the
minimum standards set forth in Section 6.1, ISOs shall be subject to the
following terms and conditions, with such additional restrictions or changes as
the Committee determines are appropriate but not in conflict with Code Section
422 and relevant regulations and rulings of the Internal Revenue Service:

              6.2.1 ISO Option Price: The Option price per Share of the Shares
subject to an ISO shall not be less than one hundred percent (100%) of the Fair
Market Value per share of the Common Stock on the date of grant of the ISO;
provided, however that the Option price per share of the Shares subject to an
ISO granted to a Participant who owns, directly or by reason of the applicable
attribution rules in Code Section 424(d), more than ten percent (10%) of the
total combined voting power of all classes of share capital of the Company or an
Affiliate, shall not be less than one hundred ten percent (110%) of the said
Fair Market Value on the date of grant.

              6.2.2 Term of ISO: Each ISO shall expire not more than ten (10)
years from the date of grant; provided, however, that an ISO granted to a
Participant who owns, directly or by reason of the applicable attribution rules
in Code Section 424(d), more than ten percent (10%) of the total combined voting
power of all classes of share capital of the Company or an Affiliate, shall
expire not more than five (5) years from the date of grant.

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              6.2.3 Limitation on Grant of ISOs: No ISOs shall be granted after
December 8, 2004, the date which is ten (10) years from the earlier of the date
of the adoption of this Plan and the date of the approval of the Plan by the
shareholders of the Company.

       6.3 LIMITATION ON NUMBER OF OPTIONS GRANTED. Notwithstanding anything in
this Plan to the contrary, no Participant shall be granted Options in any
calendar year for the purchase of more than 200,000 Shares (subject to
adjustment pursuant to Section 17 to the extent consistent with Section 162(m)
of the Code).

7.     TERMS AND CONDITIONS OF STOCK AWARDS

       Each Stock Award shall be set forth in a Stock Agreement, duly executed
by the Company and, to the extent required by law or requested by the Company,
by the Participant. The Stock Agreement shall be in the form approved by the
Committee, with such changes and modifications to such form as the Committee, in
its discretion, shall approve with respect to any particular Participant or
Participants. The Stock Agreement shall contain terms and conditions which the
Committee determines to be appropriate and in the best interest of the Company;
PROVIDED, HOWEVER, that the purchase price per share of the Shares covered by
each Stock Award shall not be less than the par value per Share. Each Stock
Agreement shall state the number of Shares to which the Stock Award pertains,
the date prior to which the Stock Award must be exercised by the Participant,
and the terms of any right of the Company to reacquire the Shares subject to the
Stock Award, including the time and events upon which such rights shall accrue
and the purchase price therefor, and any restrictions on the transferability of
such Shares.

8.     EXERCISE OF STOCK RIGHTS AND ISSUANCE OF SHARES

       A Stock Right (or any part or installment thereof) shall be exercised by
giving written notice to the Company, together with provision for payment of the
full purchase price in accordance with this Section for the Shares as to which
such Stock Right is being exercised, and upon compliance with any other
condition(s) set forth in the Stock Agreement. Such written notice shall be
signed by the person exercising the Stock Right, shall state the number of
Shares with respect to which the Stock Right is being exercised and shall
contain any representation required by the Plan or the Stock Agreement.

       Payment of the purchase price for the Shares as to which such Stock Right
is being exercised shall be made (a) in United States dollars in cash or by
check acceptable to the Committee, or (b) at the discretion of the Committee,
(i) through delivery of shares of Common Stock (which, in the case of shares
acquired from the Company, have been held by the Participant for at least six
(6) months) not subject to any restriction under any plan and having a fair
market value equal as of the date of exercise to the cash exercise price of the
Stock Right, determined in good faith by the Committee, or (ii) in accordance
with a cashless exercise program established with a securities brokerage firm,
and approved by the Company, or (iii) by any other means, including a promissory
note of the Participant, which the Committee determines to be consistent with
the purpose of this Plan and applicable law, or (iv) by any combination of the
foregoing. Notwithstanding the foregoing, the Committee shall accept only such
payment on exercise of an ISO as is permitted by Section 422 of the Code.

       The Company shall then as soon as is reasonably practicable deliver the
Shares as to which such Stock Right was exercised to the Participant (or to the
Participant's Survivors, as the case may be). It is expressly understood that
the delivery of the Shares may be delayed by the Company in order to comply with
any law or regulation which requires the Company to take any action with respect
to the Shares prior to their issuance. The Shares shall, upon delivery, be fully
paid, non-assessable Shares.

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<PAGE>

9.     RIGHTS AS A SHAREHOLDER

       No Participant to whom a Stock Right has been granted shall have rights
as a shareholder with respect to any Shares covered by such Stock Right, except
after due exercise thereof and tender of the full purchase price for the Shares
being purchased pursuant to such exercise and registration of the Shares in the
Company's share register in the name of the Participant.

10.    ASSIGNABILITY AND TRANSFERABILITY OF STOCK RIGHTS

       ISOs and, except as otherwise provided by the Committee, NQSOs and Stock
Awards shall not be transferable by the Participant other than by will or by the
laws of descent and distribution or pursuant to a qualified domestic relations
order as defined by the Code or Title I of the Employee Retirement Income
Security Act or the rules thereunder, PROVIDED, HOWEVER, that the designation of
a beneficiary of a Stock Right by a Participant shall not be deemed a transfer
prohibited by this Section. Except as provided in the preceding sentence or as
otherwise permitted under an NQSO or Stock Award Stock Agreement, a Stock Right
shall be exercisable, during the Participant's lifetime, only by such
Participant (or by his or her legal representative) and shall not be assigned,
pledged or hypothecated in any way (whether by operation of law or otherwise)
and shall not be subject to execution, attachment or similar process. Any
attempted transfer, assignment, pledge, hypothecation or other disposition of
any Stock Right or of any rights granted thereunder contrary to the provisions
of this Plan, or the levy of any attachment or similar process upon a Stock
Right, shall be null and void.

11.    EFFECT OF TERMINATION OF SERVICE

       11.1 Except as otherwise provided in the pertinent Stock Agreement or as
otherwise provided in Sections 12, 13 or 14, if a Participant ceases to be an
employee, director, consultant or advisor with the Company and its Affiliates
(for any reason other than termination "for cause", Disability, or death) (a
"Termination of Service") before the Participant has exercised all Stock Rights,
the Participant may exercise any Stock Right granted to him or her to the extent
that the Stock Right is exercisable on the date of such Termination of Service,
but only within the originally prescribed term of the Stock Right.

       11.2 The provisions of this Section, and not the provisions of Section 13
or 14, shall apply to a Participant who subsequently becomes disabled or dies
after the Termination of Service; provided, however, that in the case of a
Participant's death within three (3) months after the Termination of Service,
the Participant's Survivors may exercise the Stock Right within one (1) year
after the date of the Participant's death, but in no event after the date of
expiration of the term of the Stock Right.

       11.3 Notwithstanding anything herein to the contrary, if subsequent to a
Participant's Termination of Service, but prior to the exercise of a Stock
Right, the Committee determines that, either prior or subsequent to the
Participant's Termination of Service, the Participant engaged in conduct which
would constitute "cause" (as defined in Section 12), then such Participant shall
forthwith cease to have any right to exercise any Stock Right.

       11.4 Absence from work with the Company or an Affiliate because of
temporary disability or a leave of absence for any purpose, shall not, during
the period of any such absence in accordance with Company policies, be deemed,
by virtue of such absence alone, a Termination of Service, except as the
Committee may otherwise expressly provide.

                                      -6-
<PAGE>

       11.5 A change of employment or other service within or among the Company
and its Affiliates shall not be deemed a Termination of Service, so long as the
Participant continues to be an employee, director, consultant or advisor of the
Company or any Affiliate.

12.    EFFECT OF TERMINATION OF SERVICE FOR "CAUSE"

       Except as otherwise provided in the pertinent Stock Agreement, in the
event of a Termination of Service of a Participant "for cause" all outstanding
and unexercised Stock Rights as of the date the Participant is notified his or
her service is terminated "for cause" will immediately be forfeited.

       For purposes of this Section 12, "cause" shall include (and is not
limited to) dishonesty with respect to the Company and its Affiliates,
insubordination, substantial malfeasance or non-feasance of duty,
unauthorized disclosure of confidential information, conduct substantially
prejudicial to the business of the Company or any Affiliate, and termination
by the Participant in violation of an agreement by the Participant to remain
in the employ of the Company of an Affiliate. The determination of the
Committee as to the existence of cause will be conclusive on the Participant
and the Company. "Cause" is not limited to events which have occurred prior
to a Participant's Termination of Service, nor is it necessary that the
Committee's finding of "cause" occur prior to termination. If the Committee
determines, subsequent to a Participant's Termination of Service but prior to
the exercise of a Stock Right, that either prior or subsequent to the
Participant's termination the Participant engaged in conduct which would
constitute "cause," then the right to exercise any Stock Right shall be
forfeited. Any definition in an agreement between a Participant and the
Company or an Affiliate which contains a conflicting definition of "cause"
for termination and which is in effect at the time of such termination shall
supersede the definition in this Plan with respect to that Participant.

13.    EFFECT OF TERMINATION OF SERVICE FOR DISABILITY

       Except as otherwise provided in the pertinent Stock Agreement, in the
event of a termination of service with the Company and its Affiliates by reason
of Disability, the Disabled Participant may exercise any Stock Right granted to
him or her to the extent exercisable but not exercised on the date of
Disability. A Disabled Participant may exercise such rights only within a period
of not more than one (1) year after the date that the Participant became
Disabled or, if earlier, within the originally prescribed term of the Stock
Right.

       The Committee shall make the determination both of whether Disability has
occurred and of the date of its occurrence (unless a procedure for such
determination is set forth in another agreement between the Company and such
Participant, in which case such procedure shall be used for such determination).
If requested, the Participant shall be examined by a physician selected or
approved by the Committee, the cost of which examination shall be paid for by
the Company.

14.    EFFECT OF DEATH WHILE AN EMPLOYEE, DIRECTOR OR CONSULTANT

       Except as otherwise provided in the pertinent Stock Agreement, in the
event of death of a Participant while the Participant is an employee, director,
consultant or advisor of the Company or of an Affiliate, any Stock Rights
granted to such Participant may be exercised by the Participant's Survivors to
the extent exercisable but not exercised on the date of death. Any such Stock
Right must be exercised within one (1) year after the date of death of the
Participant, but in no event after the date of expiration of the term of the
Stock Right.

15.      PURCHASE FOR INVESTMENT

         Unless the offering and sale of the Shares to be issued upon the
particular exercise of an Stock Right shall have been effectively registered
under the Securities Act of 1933, as now in force

                                      -7-
<PAGE>

or hereafter amended (the "1933 Act"), the Company shall be under no obligation
to issue the Shares covered by such exercise unless and until the following
conditions have been fulfilled:

     a.  The person(s) who exercise such Stock Right shall warrant to the
         Company, at the time of such exercise or receipt, as the case may be,
         that such person(s) are acquiring such Shares for their own respective
         accounts, for investment, and not with a view to, or for sale in
         connection with, the distribution of any such Shares, in which event
         the person(s) acquiring such Shares shall be bound by the provisions of
         the following legend which shall be endorsed upon the certificate(s)
         evidencing their Shares issued pursuant to such exercise or such grant:

                  "The shares represented by this certificate have been taken
                  for investment and they may not be sold or otherwise
                  transferred by any person, including a pledgee, unless (1)
                  either (a) a Registration Statement with respect to such
                  shares shall be effective under the Securities Act of 1933, as
                  amended, or (b) the Company shall have received an opinion of
                  counsel satisfactory to it that an exemption from registration
                  under such Act is then available, and (2) there shall have
                  been compliance with all applicable state securities laws.

     b.  The Company shall have received an opinion of its counsel that the
         Shares may be issued upon such particular exercise in compliance with
         the 1933 Act without registration thereunder.

         The Company may delay issuance of the Shares until completion of any
action or obtaining of any consent which the Company deems necessary under any
applicable law (including, without limitation, state securities or "blue sky"
laws).

16.      DISSOLUTION OR LIQUIDATION OF THE COMPANY

         Upon the dissolution or liquidation of the Company (other than in
connection with a transaction subject to the provisions of Section 17.2), all
Stock Rights granted under this Plan which as of such date shall not have been
exercised will terminate and become null and void; provided, however, that if
the rights of a Participant have not otherwise terminated and expired, the
Participant will have the right immediately prior to such dissolution or
liquidation to exercise any Stock Right to the extent that such Stock Right is
exercisable as of the date immediately prior to such dissolution or liquidation.

17.      ADJUSTMENTS

         Upon the occurrence of any of the following events, a Participant's
rights with respect to any Stock Right granted to him or her hereunder which
have not previously been exercised in full shall be adjusted as hereinafter
provided, unless otherwise specifically provided in the written agreement
between the Participant and the Company relating to such Stock Right or in any
employment agreement between a Participant and the Company or an Affiliate:

      17.1 STOCK DIVIDENDS AND STOCK SPLITS. If the shares of Common Stock shall
be subdivided or combined into a greater or smaller number of shares or if the
Company shall issue any shares of Common Stock as a stock dividend on its
outstanding Common Stock, the number of shares of Common Stock deliverable upon
the exercise of such Stock Right shall be appropriately increased or decreased,
and appropriate adjustments shall be made in the purchase price per share to
reflect such subdivision, combination or stock dividend.

      17.2 CONSOLIDATIONS OR MERGERS. In the event of a consolidation or merger
in which the Company is not the surviving corporation or which results in the
acquisition of substantially all the

                                      -8-
<PAGE>

Company's outstanding stock by a single person or entity or by a group of
persons and/or entities acting in concert, or in the event of the sale or
transfer of substantially all the Company's assets (any of the foregoing, an
"Acquisition"), all then outstanding Options shall terminate unless assumed
pursuant to clause (i) below; provided, that either (i) the Committee shall
provide for the surviving or acquiring entity or an affiliate thereof to assume
the outstanding Options or grant replacement options in lieu thereof, any such
replacement to be upon an equitable basis as determined by the Committee, or
(ii) if there is no such assumption or substitution, all outstanding Options
shall become immediately and fully exercisable immediately prior to the
Acquisition, notwithstanding any restrictions or vesting conditions set forth
therein.

      17.3 RECAPITALIZATION OR REORGANIZATION. In the event of a
recapitalization or reorganization of the Company (other than a transaction
described in Section 17.2 above) pursuant to which securities of the Company or
of another corporation are issued with respect to the outstanding shares of
Common Stock, a Participant upon exercising a Stock Right shall be entitled to
receive for the purchase price paid upon such exercise the securities he or she
would have received if he or she had exercised such Stock Right prior to such
recapitalization or reorganization.

      17.4 MODIFICATION OF ISOS. Notwithstanding the foregoing, any adjustments
made pursuant to Section 17.1, 17.2 or 17.3 with respect to ISOs shall be made
only after the Committee determines whether such adjustments would constitute a
"modification" of such ISOs (as that term is defined in Section 424(h) of the
Code) or would cause any adverse tax consequences for the holders of such ISOs.
If the Committee determines that such adjustments made with respect to ISOs
would constitute a modification of such ISOs, it may refrain from making such
adjustments, unless the holder of an ISO specifically requests in writing that
such adjustment be made and such writing indicates that the holder has full
knowledge of the consequences of such "modification" on his or her income tax
treatment with respect to the ISO.

18.      ISSUANCES OF SECURITIES

         Except as expressly provided herein, no issuance (including for this
purpose the delivery of shares held in treasury) by the Company of shares of
stock of any class, or securities convertible into shares of stock of any class,
shall affect, and no adjustment by reason thereof shall be made with respect to,
the number or price of Shares subject to Options. Except as expressly provided
herein, no adjustments shall be made for dividends paid in cash or in property
(including without limitation, securities) of the Company.

19.      FRACTIONAL SHARES

         No fractional share shall be issued under the Plan and the person
exercising any Stock Right shall receive from the Company cash in lieu of any
such fractional share equal to the Fair Market Value thereof determined in good
faith by the Board of Directors.

20.      CONVERSION OF ISOS INTO NON-QUALIFIED OPTIONS: TERMINATION OF ISOS

       Any Options granted under this Plan which do not meet the requirements of
the Code for ISOs shall automatically be deemed to be NQSOs without further
action on the part of the Committee. The Committee, at the written request of
any Participant, may in its discretion take such actions as may be necessary to
convert such Participant's ISOs (or any portion thereof) that have not been
exercised on the date of conversion into NQSOs at any time prior to the
expiration of such ISOs, regardless of whether the Participant is an employee of
the Company or an Affiliate at the time of such conversion. Such actions may
include, but not be limited to, extending the exercise period or reducing the
exercise price of the appropriate installments of such Options. At the time of
such conversion, the Committee (with the consent of the Participant) may impose
such

                                      -9-
<PAGE>

conditions on the exercise of the resulting NQSOs as the Committee in its
discretion may determine, provided that such conditions shall not be
inconsistent with this Plan. Nothing in the Plan shall be deemed to give any
Participant the right to have such Participant's ISOs converted into NQSOs, and
no such conversion shall occur until and unless the Committee takes appropriate
action. The Committee, with the consent of the Participant, may also terminate
any portion of any ISO that has not been exercised at the time of such
termination.

21.      WITHHOLDING

         In the event that any federal, state, or local income taxes, employment
taxes, Federal Insurance Contributions Act ("FICA") withholdings or other
amounts are required by applicable law or governmental regulation to be withheld
from the Participant's salary, wages or other remuneration in connection with
the exercise of a Stock Right or a Disqualifying Disposition (as defined in
Section 22), the Participant shall advance in cash to the Company, or to any
Affiliate of the Company which employs or employed the Participant, the amount
of such withholdings unless a different withholding arrangement, including the
use of shares of the Company's Common Stock, is authorized by the Committee (and
permitted by law), provided, however, that with respect to persons subject to
Section 16 of the Exchange Act, any such withholding arrangement shall be in
compliance with any applicable provisions of Rule 16b-3 promulgated under
Section 16 of the Exchange Act. For purposes hereof, the Fair Market Value of
any shares withheld for purposes of payroll withholding shall be determined in
the manner provided in Section 1 above, as of the most recent practicable date
prior to the date of exercise. If the Fair Market Value of the shares withheld
is less than the amount of payroll withholdings required, the Participant my be
required to advance the difference in cash to the Company or the Affiliate
employer. The Committee in its discretion may condition the exercise of an
Option for less than the then Fair Market Value on the Participant's payment of
such additional withholding. In no event shall shares be withheld from any award
in satisfaction of tax withholding requirements in an amount that exceeds the
minimum tax withholding requirements of law.

22.      NOTICE TO COMPANY OF DISQUALIFYING DISPOSITION

         Each Key Employee who receives an ISO must agree to notify the Company
in writing immediately after the Key Employee makes a "Disqualifying
Disposition" of any Shares acquired pursuant to the exercise of an ISO. A
Disqualifying Disposition is any disposition (as defined in Section 424(c) of
the Code) of such shares before the later of (a) two years from the date the Key
Employee was granted the ISO, or (b) one year after the date the Key Employee
acquired Shares by exercising the ISO. If the Key Employee has died before such
Shares are sold, the notice provisions of this Section 22 shall not apply.

23.      EFFECTIVE DATE; TERMINATION OF THE PLAN

         The Plan shall be effective on December 8, 1994, the date it is
approved by the Board of Directors. The Plan will terminate on December 8, 2004,
the date which is ten (10) years from the earlier of the date of its adoption or
the date of its approval by the stockholders of the Company. The Plan may be
terminated at an earlier date by vote of the stockholders of the Company;
provided, however, that any such earlier termination will not affect any Stock
Rights granted or Stock Agreements executed prior to the effective date of such
termination.

24.      AMENDMENT OF THE PLAN; AMENDMENT OF STOCK RIGHTS

         The Plan may be amended by the stockholders of the Company. The Plan
may also be amended by the Board of Directors or the Committee, including,
without limitation, to the extent necessary to qualify any or all outstanding
Stock Rights granted under the Plan or Stock Rights to be granted under the Plan
for favorable federal income tax treatment (including deferral of taxation

                                      -10-
<PAGE>

upon exercise) as may be afforded incentive stock options under Section 422 of
the Code, to the extent necessary to ensure that Stock Rights granted or to be
granted under the Plan are in accordance with Rule 16b-3 under the Exchange Act,
and to the extent necessary to qualify the shares issuable upon exercise of any
outstanding Stock Rights granted, or Stock Rights to be granted, under the Plan
for listing on any national securities exchange or quotation in any national
automated quotation system of securities dealers. Any amendment approved by the
Board of Directors or the Committee which is of a scope that requires
stockholder approval in order to ensure favorable federal income tax treatment
for any ISOs or Section 162(m) of the Code shall be subject to obtaining such
stockholder approval. No modification or amendment of the Plan shall adversely
affect a Participant's rights under a Stock Right previously granted to the
Participant without such Participant's consent.

         In its discretion, the Committee may amend any term or condition of any
outstanding Stock Right, PROVIDED, (i) such term or condition as amended is
permitted by the Plan, (ii) if the amendment is adverse to the Participant, such
amendment shall be made only with the consent of the Participant, (iii) any such
amendment of any ISO shall be made only after the Committee determines whether
such amendment would constitute a "modification" of any Stock Right which is an
ISO (as that term is defined in Section 424(h) of the Code) or would cause any
adverse tax consequences for the holder of such ISO, and (iv) with respect to
any Stock Right held by any Participant who is subject to the provisions of
Section 16(a) of the Exchange Act, any such amendment shall be made only after
the Committee determines whether such amendment would constitute the grant of a
new Stock Right.

25.      EMPLOYMENT OR OTHER RELATIONSHIP

         Nothing in this Plan or any Stock Agreement shall be deemed to prevent
the Company or an Affiliate from terminating the employment, consultancy or
director status of a Participant, nor to prevent a Participant from terminating
his or her own employment, consultancy or director status or to give any
Participant a right to be retained in employment or other service by the Company
or any Affiliate for any period of time.

26.      GOVERNING LAW

         This Plan shall be construed and enforced in accordance with the law of
The Commonwealth of Massachusetts.

rev. 11/18/99/SPC

                                      -11-

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