<PAGE>

                                                                   EXHIBIT 10.15

          AMENDED AND RESTATED NORTHPOINT COMMUNICATIONS GROUP, INC.

                                1999 STOCK PLAN

  1. Purposes of the Plan. The purposes of the 1999 Stock Plan are to attract
and retain the best available personnel for positions of substantial
responsibility, to provide additional incentive to Employees, Directors and
Consultants and to promote the success of the Company's business. Options
granted under the Plan may be Incentive Stock Options or Nonstatutory Stock
Options, as determined by the Administrator at the time of grant. Stock
Purchase Rights may also be granted under the Plan.

  2. Definitions. As used herein, the following definitions shall apply:

  (a) "Administrator" means the Committee responsible for conducting the
general administration of the Plan in accordance with Section 4 hereof.

  (b) "Applicable Laws" means the requirements relating to the administration
of stock option plans under U.S. state corporate laws, U.S. federal and state
securities laws, the Code, any stock exchange or quotation system on which the
Common Stock is listed or quoted and the applicable laws of any foreign
country or jurisdiction where Options or Stock Purchase Rights are granted
under the Plan.

  (c) "Board" means the Board of Directors of the Company.

  (d) "Code" means the Internal Revenue Code of 1986, as amended.

  (e) "Committee" means a committee of Independent Directors appointed by the
Board in accordance with Section 4 hereof.

  (f) "Common Stock" means the Common Stock of the Company, par value $.001
per share.

  (g) "Company" means NorthPoint Communications Group, Inc., a Delaware
corporation.

  (h) "Consultant" means any consultant or adviser if: (i) the consultant or
adviser renders bona fide services to the Company; (ii) the services rendered
by the consultant or adviser are not in connection with the offer or sale of
securities in a capital-raising transaction and do not directly or indirectly
promote or maintain a market for the Company's securities; and (iii) the
consultant or adviser is a natural person who has contracted directly with the
Company to render such services.

  (i) "Director" means a member of the Board of Directors of the Company.

  (j) "Employee" means any person, including Officers and Directors, employed
by the Company or any Parent or Subsidiary of the Company. A Service Provider
shall not cease to be an Employee in the case of (i) any leave of absence
approved by the Company or (ii) transfers between locations of the Company or
between the Company, its Parent, any Subsidiary, or any successor. For
purposes of Incentive Stock Options, no such leave may exceed ninety (90)
days, unless reemployment upon expiration of such leave is guaranteed by
statute or contract. Neither service as a Director nor payment of a director's
fee by the Company shall be sufficient, by itself, to constitute "employment"
by the Company.

  (k) "Exchange Act" means the Securities Exchange Act of 1934, as amended.

  (l) "Fair Market Value" means, as of any date, the value of Common Stock
determined as follows:

    (i) If the Common Stock is listed on any established stock exchange or a
  national market system, including, without limitation, the Nasdaq National
  Market or The Nasdaq SmallCap Market of The Nasdaq Stock Market, its Fair
  Market Value shall be the closing sales price for such stock (or the
  closing bid, if no sales were reported) as quoted on such exchange or
  system for the last market trading day prior to the time

                                       1
<PAGE>

  of determination, as reported in The Wall Street Journal or such other
  source as the Administrator deems reliable;

    (ii) If the Common Stock is regularly quoted by a recognized securities
  dealer but selling prices are not reported, its Fair Market Value shall be
  the mean between the high bid and low asked prices for the Common Stock on
  the last market trading day prior to the day of determination; or

    (iii) In the absence of an established market for the Common Stock, the
  Fair Market Value thereof shall be determined in good faith by the
  Administrator.

  (m) "Incentive Stock Option" means an Option intended to qualify as an
incentive stock option within the meaning of Section 422 of the Code and which
is designated as an Incentive Stock Option by the Administrator.

  (n) "Independent Director" means a Director who is not an Employee of the
Company.

  (o) "Nonstatutory Stock Option" means an Option not intended to qualify as
an Incentive Stock Option which is not designated as an Incentive Stock Option
by the Administrator.

  (p) "Officer" means a person who is an officer of the Company within the
meaning of Section 16 of the Exchange Act and the rules and regulations
promulgated thereunder.

  (q) "Option" means a stock option granted pursuant to the Plan.

  (r) "Option Agreement" means a written agreement between the Company and an
Optionee evidencing the terms and conditions of an individual Option grant.
The Option Agreement is subject to the terms and conditions of the Plan.

  (s) "Optioned Stock" means the Common Stock subject to an Option or a Stock
Purchase Right.

  (t) "Optionee" means the holder of an outstanding Option or Stock Purchase
Right granted under the Plan.

  (u) "Parent" means a "parent corporation," whether now or hereafter
existing, as defined in Section 424(e) of the Code.

  (v) "Plan" means the NorthPoint Communications Group, Inc. 1999 Stock Plan.

  (w) "Restricted Stock" means shares of Common Stock acquired pursuant to a
Stock Purchase Right granted under Section 12 below.

  (x) "Rule 16b-3" means that certain Rule 16b-3 under the Exchange Act, as
such Rule may be amended from time to time.

  (y) "Section 16(b)" means Section 16(b) of the Securities Exchange Act of
1934, as amended.

  (z) "Service Provider" means an Employee, Director or Consultant.

  (aa) "Share" means a share of the Common Stock, as adjusted in accordance
with Section 15 below.

  (bb) "Stock Purchase Right" means a right to purchase Common Stock pursuant
to Section 12 below.

  (cc) "Subsidiary" means a "subsidiary corporation," whether now or hereafter
existing, as defined in Section 424(f) of the Code.

                                       2
<PAGE>

  3. Stock Subject to the Plan. Subject to the provisions of Section 15 of the
Plan, the shares of stock subject to Options or Stock Purchase Rights shall be
Common Stock, initially shares of the Company's Common Stock, par value $.001
per share. Subject to the provisions of Section 15 of the Plan, the maximum
aggregate number of Shares which may be issued upon exercise of such Options
or Stock Purchase Rights is the sum of: (i) 21,250,000 Shares; (ii) the number
of shares of common stock of NorthPoint Communications, Inc., which remain
available for grants of options under the NorthPoint Communications, Inc. 1997
Stock Option Plan as of the date of the Plan's initial adoption by the Board
and (iii) with respect to options granted under the NorthPoint Communications,
Inc. 1997 Stock Option Plan that are assumed by the Company and expire or are
canceled without having been exercised in full, the number of Shares subject
to each such option as to which such option was not exercised prior to its
expiration or cancellation; provided, however, that, during the term of the
Plan, on each anniversary of the date of the Plan's initial adoption by the
Board (commencing with the first such anniversary), such maximum aggregate
number of Shares shall be increased by an amount equal to 5% of the total
number of shares of Common Stock outstanding on such anniversary date.

  Notwithstanding the foregoing, the maximum aggregate number of Shares which
may be issued upon exercise of Incentive Stock Options (the "ISO Limitation")
is 21,250,000 Shares.

  Shares issued upon exercise of Options or Stock Purchase Rights may be
authorized but unissued, or reacquired Common Stock. If an Option or Stock
Purchase Right expires or becomes unexercisable without having been exercised
in full, the unpurchased Shares which were subject thereto shall become
available for future grant or sale under the Plan (unless the Plan has
terminated). Shares which are delivered by the Optionee or withheld by the
Company upon the exercise of an Option or Stock Purchase Right under the Plan,
in payment of the exercise price thereof or tax withholding thereon, may again
be optioned, granted or awarded hereunder, subject to the limitations of this
Section 3. If Shares of Restricted Stock are repurchased by the Company at
their original purchase price, such Shares shall become available for future
grant under the Plan. Notwithstanding the provisions of this Section 3, no
Shares may again be optioned, granted or awarded if such action would cause an
Incentive Stock Option to fail to qualify as an Incentive Stock Option under
Code Section 422.

  4. Administration of the Plan.

  (a) Administrator. The Plan shall be administered by the Compensation
Committee of the Board (or another committee or a subcommittee of the Board
designated as the Administrator under the Plan) which shall consist solely of
two or more Independent Directors appointed by and holding office at the
pleasure of the Board, each of whom is both a "non-employee director" as
defined by Rule 16b-3 and an "outside director" for purposes of Section 162(m)
of the Code. Within the scope of such authority, the Board or the Committee
may (i) delegate to a committee of one or more members of the Board who are
not Independent Directors the authority to grant awards under the Plan to
eligible persons who are either (1) not then "covered employees," within the
meaning of Section 162(m) of the Code and are not expected to be "covered
employees" at the time of recognition of income resulting from such award or
(2) not persons with respect to whom the Company wishes to comply with Section
162(m) of the Code and/or (ii) delegate to a committee of one or more members
of the Board who are not "non-employee directors," within the meaning of Rule
16b-3, the authority to grant awards under the Plan to eligible persons who
are not then subject to Section 16 of the Exchange Act. The Board may abolish
the Committee at any time and revest in the Board the administration of the
Plan. Appointment of Committee members shall be effective upon acceptance of
appointment. Committee members may resign at any time by delivering written
notice to the Board. Vacancies in the Committee may be filled by the Board.

  (b) Powers of the Administrator. Subject to the provisions of the Plan and
the specific duties delegated by the Board to such Committee, and subject to
the approval of any relevant authorities, the Administrator shall have the
authority in its discretion:

    (i) to determine the Fair Market Value;

    (ii) to select the Service Providers to whom Options and Stock Purchase
  Rights may from time to time be granted hereunder;

                                       3
<PAGE>

    (iii) to determine the number of Shares to be covered by each such award
  granted hereunder;

    (iv) to approve forms of agreement for use under the Plan;

    (v) subject to clause 9(a)(iii)(B) below, to determine the terms and
  conditions of any Option or Stock Purchase Right granted hereunder (such
  terms and conditions include, but are not limited to, the exercise price,
  the time or times when Options or Stock Purchase Rights may be exercised
  (which may be based on performance criteria), any vesting acceleration or
  waiver of forfeiture restrictions, and any restriction or limitation
  regarding any Option or Stock Purchase Right or the Common Stock relating
  thereto, based in each case on such factors as the Administrator, in its
  sole discretion, shall determine);

    (vi) to determine whether and under what circumstances an Option may be
  settled in cash under subsection 10(g) instead of Common Stock;

    (vii) to prescribe, amend and rescind rules and regulations relating to
  the Plan, including rules and regulations relating to sub-plans established
  for the purpose of qualifying for preferred tax treatment under foreign tax
  laws;

    (viii) to allow Optionees to satisfy withholding tax obligations by
  electing to have the Company withhold from the Shares to be issued upon
  exercise of an Option or Stock Purchase Right that number of Shares having
  a Fair Market Value equal to the amount required to be withheld. The Fair
  Market Value of the Shares to be withheld shall be determined on the date
  that the amount of tax to be withheld is to be determined. All elections by
  Optionees to have Shares withheld for this purpose shall be made in such
  form and under such conditions as the Administrator may deem necessary or
  advisable; and

    (ix) to construe and interpret the terms of the Plan and awards granted
  pursuant to the Plan.

  (c) Effect of Administrator's Decision. All decisions, determinations and
interpretations of the Administrator shall be final and binding on all
Optionees.

  5. Eligibility. Nonstatutory Stock Options and Stock Purchase Rights may be
granted to Service Providers. Incentive Stock Options may be granted only to
Employees. If otherwise eligible, an Employee or Consultant who has been
granted an Option or Stock Purchase Right may be granted additional Options or
Stock Purchase Rights. Each Independent Director shall be eligible to be
granted Options at the times and in the manner set forth in Section 12.

  6. Limitations.

  (a) Each Option shall be designated by the Administrator in the Option
Agreement as either an Incentive Stock Option or a Nonstatutory Stock Option.
However, notwithstanding such designations, to the extent that the aggregate
Fair Market Value of Shares subject to an Optionee's Incentive Stock Options
and other incentive stock options granted by the Company, any Parent or
Subsidiary, which become exercisable for the first time during any calendar
year (under all plans of the Company or any Parent or Subsidiary) exceeds
$100,000, such excess Options or other options shall be treated as
Nonstatutory Stock Options.

  For purposes of this Section 6(a), Incentive Stock Options shall be taken
into account in the order in which they were granted, and the Fair Market
Value of the Shares shall be determined as of the time of grant.

  (b) Neither the Plan, any Option nor any Stock Purchase Right shall confer
upon an Optionee any right with respect to continuing the Optionee's
employment or consulting relationship with the Company, nor shall they
interfere in any way with the Optionee's right or the Company's right to
terminate such employment or consulting relationship at any time, with or
without cause.

  (c) No Employee shall be granted, in any calendar year, Options or Stock
Purchase Rights to purchase more than 2,100,000 Shares.

  (d) The foregoing limitation shall be adjusted proportionately in connection
with any change in the Company's capitalization as described in Section 15.

                                       4
<PAGE>

  (e) If an Option is canceled in the same fiscal year of the Company it was
granted (other than in connection with a transaction described in Section 15),
the canceled Option will be counted against the limit set forth in Section
6(c). For this purpose, if the exercise price of an Option is reduced, the
transaction shall be treated as a cancellation of the Option and the grant of
a new Option.

  7. Term of Plan. The Plan shall become effective upon its initial adoption
by the Board. It shall continue in effect for a term of ten (10) years unless
sooner terminated under Section 17 of the Plan.

  8. Term of Option. The term of each Option shall be stated in the Option
Agreement; provided, however, that the term shall be no more than ten (10)
years from the date of grant thereof. In the case of an Incentive Stock Option
granted to an Optionee who, at the time the Option is granted, owns (or is
treated as owning under Code Section 424) stock representing more than ten
percent (10%) of the voting power of all classes of stock of the Company or
any Parent or Subsidiary, the term of the Option shall be five (5) years from
the date of grant or such shorter term as may be provided in the Option
Agreement.

  9. Option Exercise Price and Consideration.

  (a) Except as provided in Section 12, the per share exercise price for the
Shares to be issued upon exercise of an Option shall be such price as is
determined by the Administrator (or the Board, as provided in clause
(a)(iii)(B) below), but shall be subject to the following:

    (i) In the case of an Incentive Stock Option

      (A) granted to an Employee who, at the time of grant of such Option,
    owns (or is treated as owning under Code Section 424) stock
    representing more than ten percent (10%) of the voting power of all
    classes of stock of the Company or any Parent or Subsidiary, the per
    Share exercise price shall be no less than one hundred ten percent
    (110%) of the Fair Market Value per Share on the date of grant.

      (B) granted to any other Employee, the per Share exercise price shall
    be no less than one hundred percent (100%) of the Fair Market Value per
    Share on the date of grant.

    (ii) In the case of a Nonstatutory Stock Option

      (A) granted to a Service Provider who, at the time of grant of such
    Option, owns stock representing more than ten percent (10%) of the
    voting power of all classes of stock of the Company or any Parent or
    Subsidiary, the exercise price shall be no less than one hundred ten
    percent (110%) of the Fair Market Value per Share on the date of the
    grant.

      (B) granted to any other Service Provider, the per Share exercise
    price shall be no less than eighty-five percent (85%) of the Fair
    Market Value per Share on the date of grant.

    (iii) Notwithstanding the foregoing,

      (A) Options may be granted with a per Share exercise price other than
    as required above pursuant to a merger or other corporate transaction.

      (B) Nonstatutory Stock Options granted to any Service Provider who
    will serve as an Officer may be granted with a per Share exercise price
    other than as required above; provided, however, that any such grant
    shall be approved by both the Administrator and the full Board.

  (b) The consideration to be paid for the Shares to be issued upon exercise
of an Option, including the method of payment, shall be determined by the
Administrator (and, in the case of an Incentive Stock Option, shall be
determined at the time of grant). Such consideration may consist of (1) cash,
(2) check, (3) full recourse promissory note bearing interest (at no less than
such rate as shall then preclude the imputation of interest under the Code)
and payable upon such terms as may be prescribed by the Administrator), (4)
other Shares which (x) in the case of Shares acquired upon exercise of an
Option, have been owned by the Optionee for more than

                                       5
<PAGE>

six (6) months on the date of surrender, and (y) have a Fair Market Value on
the date of surrender equal to the aggregate exercise price of the Shares as
to which such Option shall be exercised, (5) surrendered Shares then issuable
upon exercise of the Option having a Fair Market Value on the date of exercise
equal to the aggregate exercise price of the Option or exercised portion
thereof, (6) property of any kind which constitutes good and valuable
consideration, (7) delivery of a notice that the Optionee has placed a market
sell order with a broker with respect to Shares then issuable upon exercise of
the Options and that the broker has been directed to pay a sufficient portion
of the net proceeds of the sale to the Company in satisfaction of the Option
exercise price, provided, that payment of such proceeds is then made to the
Company upon settlement of such sale, or (8) any combination of the foregoing
methods of payment. In making its determination as to the type of
consideration to accept, the Administrator shall consider if acceptance of
such consideration may be reasonably expected to benefit the Company.

  10. Exercise of Option.

  (a) Vesting; Fractional Exercises. Except as provided in Section 13, Options
granted hereunder shall be exercisable according to the terms hereof at such
times and under such conditions as determined by the Administrator and set
forth in the Option Agreement, but in no case at a rate of less than twenty
percent (20%) per year over five (5) years from the date the Option is
granted. Unless the Administrator provides otherwise, vesting of Options
granted hereunder shall be tolled during any unpaid leave of absence. An
Option may not be exercised for a fraction of a Share.

  (b) Deliveries upon Exercise. All or a portion of an exercisable Option
shall be deemed exercised upon delivery of all of the following to the
Secretary of the Company or his or her office:

    (i) A written or electronic notice complying with the applicable rules
  established by the Administrator stating that the Option, or a portion
  thereof, is exercised. The notice shall be signed by the Optionee or other
  person then entitled to exercise the Option or such portion of the Option;

    (ii) Such representations and documents as the Administrator, in its
  absolute discretion, deems necessary or advisable to effect compliance with
  Applicable Laws. The Administrator may, in its absolute discretion, also
  take whatever additional actions it deems appropriate to effect such
  compliance, including, without limitation, placing legends on share
  certificates and issuing stop transfer notices to agents and registrars;
  and

    (iii) In the event that the Option shall be exercised pursuant to Section
  10(f) by any person or persons other than the Optionee, appropriate proof
  of the right of such person or persons to exercise the Option.

  (c) Conditions to Delivery of Share Certificates. The Company shall not be
required to issue or deliver any certificate or certificates for Shares
purchased upon the exercise of any Option or portion thereof prior to
fulfillment of all of the following conditions:

    (i) The admission of such Shares to listing on all stock exchanges on
  which such class of stock is then listed;

    (ii) The completion of any registration or other qualification of such
  Shares under any state or federal law, or under the rulings or regulations
  of the Securities and Exchange Commission or any other governmental
  regulatory body which the Administrator shall, in its absolute discretion,
  deem necessary or advisable;

    (iii) The obtaining of any approval or other clearance from any state or
  federal governmental agency which the Administrator shall, in its absolute
  discretion, determine to be necessary or advisable;

    (iv) The lapse of such reasonable period of time following the exercise
  of the Option as the Administrator may establish from time to time for
  reasons of administrative convenience; and

                                       6
<PAGE>

    (v) The receipt by the Company of full payment for such Shares, including
  payment of any applicable withholding tax, which in the discretion of the
  Administrator may be in the form of consideration used by the Optionee to
  pay for such Shares under Section 9(b).

  (d) Termination of Relationship as a Service Provider. If an Optionee ceases
to be a Service Provider, such Optionee may exercise his or her Option within
such period of time as is specified in the Option Agreement to the extent that
the Option is vested on the date of termination (but in no event later than
the expiration of the term of the Option as set forth in the Option
Agreement). In the absence of a specified time in the Option Agreement, the
Option shall remain exercisable for three (3) months following the Optionee's
termination. If, on the date of termination, the Optionee is not vested as to
his or her entire Option, the Shares covered by the unvested portion of the
Option shall again become available for issuance under the Plan. If, after
termination, the Optionee does not exercise his or her Option within the time
period specified by the Administrator in the Option Agreement relating to such
Option, the Option shall terminate, and the Shares covered by such Option
shall again become available for issuance under the Plan.

  (e) Disability of Optionee. If an Optionee ceases to be a Service Provider
as a result of the Optionee's Disability, the Optionee may exercise his or her
Option within such period of time as is specified in the Option Agreement to
the extent the Option is vested on the date of termination (but in no event
later than the expiration of the term of such Option as set forth in the
Option Agreement). In the absence of a specified time in the Option Agreement,
the Option shall remain exercisable for twelve (12) months following the
Optionee's termination. If such disability is not a "disability" as such term
is defined in Section 22(e)(3) of the Code, in the case of an Incentive Stock
Option such Incentive Stock Option shall automatically cease to be treated as
an Incentive Stock Option and shall be treated for tax purposes as a
Nonstatutory Stock Option on the day three (3) months and one (1) day
following such termination. If, on the date of termination, the Optionee is
not vested as to his or her entire Option, the Shares covered by the unvested
portion of the Option shall revert to the Plan. If, after termination, the
Optionee does not exercise his or her Option within the time specified herein,
the Option shall terminate, and the Shares covered by such Option shall revert
to the Plan.

  (f) Death of Optionee. If an Optionee dies while a Service Provider, the
Option may be exercised within such period of time as is specified in the
Option Agreement (but in no event later than the expiration of the term of
such Option as set forth in the Notice of Grant), by the Optionee's estate or
by a person who acquires the right to exercise the Option by bequest or
inheritance, but only to the extent that the Option is vested on the date of
death. In the absence of a specified time in the Option Agreement, the Option
shall remain exercisable for twelve (12) months following the Optionee's
termination. If, at the time of death, the Optionee is not vested as to his or
her entire Option, the Shares covered by the unvested portion of the Option
shall immediately revert to the Plan. The Option may be exercised by the
executor or administrator of the Optionee's estate or, if none, by the
person(s) entitled to exercise the Option under the Optionee's will or the
laws of descent or distribution. If the Option is not so exercised within the
time specified herein, the Option shall terminate, and the Shares covered by
such Option shall revert to the Plan.

  (g) Buyout Provisions. The Administrator may at any time offer to buy out
for a payment in cash or Shares, an Option previously granted, based on such
terms and conditions as the Administrator shall establish and communicate to
the Optionee at the time that such offer is made.

  11. Non-Transferability of Options and Stock Purchase Rights. Options and
Stock Purchase Rights may not be sold, pledged, assigned, hypothecated,
transferred, or disposed of in any manner other than by will or by the laws of
descent or distribution and may be exercised, during the lifetime of the
Optionee, only by the Optionee.

  12. Granting of Options to Independent Directors. During the term of the
Plan, a person who is an Independent Director as of the date of the
consummation of the initial public offering of Common Stock, or a person who
is initially elected to the Board following the consummation of the initial
public offering of Common Stock and who is an Independent Director at the time
of such initial election, automatically shall be granted (i) an

                                       7
<PAGE>

Option to purchase forty thousand (40,000) shares of Common Stock (subject to
adjustment as provided in Section 15) on the date of such consummation or such
initial election, as applicable (each, an "Initial Option") and (ii) an Option
to purchase thirteen thousand (13,000) shares of Common Stock (subject to
adjustment as provided in Section 15) on the date of each annual meeting of
stockholders after the date of the Board's adoption of the Plan at which the
Independent Director is reelected to the Board (a "Subsequent Option").
Members of the Board who are employees of the Company who subsequently retire
from the Company and remain on the Board will not receive an initial Option
grant pursuant to clause (i) of the preceding sentence, but to the extent that
they are otherwise eligible, will receive, after retirement from employment
with the Company, Options as described in clause (ii) of the preceding
sentence. All the foregoing Option grants authorized by this Section 12 are
subject to stockholder approval of the Plan.

  13. Terms of Options Granted to Independent Directors. The per Share price
of each Option granted to an Independent Director shall equal 100% of the Fair
Market Value of a share of Common Stock on the date the Option is granted;
provided, however, that the per Share price of each Option granted to an
Independent Director on the date of the initial public offering of Common
Stock shall equal the initial public offering price (net of underwriting
discounts and commissions) per Share. Initial Options (as defined in Section
12) granted to Independent Directors shall become exercisable in cumulative
monthly installments of 1/36 of the Shares subject to such option on each of
the monthly anniversaries of the date of Initial Option grant, commencing with
the first such monthly anniversary, such that each Initial Option shall be one
hundred percent (100%) vested on the third anniversary of its date of grant.
Subsequent Options (as defined in Section 12) granted to Independent Directors
shall become vested in cumulative monthly installments of 1/12 of the Shares
subject to such Option on each of the monthly anniversaries of the date of
Subsequent Option grant, commencing with the twenty-fifth monthly anniversary
of such date of Subsequent Option grant, such that each Subsequent Option
shall be one hundred percent (100%) vested on the third anniversary of the
date of Subsequent Option grant. Subject to Section 10, the term of each
Option granted to an Independent Director shall be ten (10) years from the
date the Option is granted. No portion of an Option which is unexercisable at
the time of an Independent Director's termination of membership on the Board
shall thereafter become exercisable.

  14. Stock Purchase Rights.

  (a) Rights to Purchase. Stock Purchase Rights may be issued either alone, in
addition to, or in tandem with other awards granted under the Plan and/or cash
awards made outside of the Plan. After the Administrator determines that it
will offer Stock Purchase Rights under the Plan, it shall advise the offeree
in writing of the terms, conditions and restrictions related to the offer,
including the number of Shares that such person shall be entitled to purchase,
the price to be paid, and the time within which such person must accept such
offer. The offer shall be accepted by execution of a Restricted Stock purchase
agreement in the form determined by the Administrator.

  (b) Repurchase Option. Unless the Administrator determines otherwise, the
Restricted Stock purchase agreement shall grant the Company a repurchase
option exercisable upon the voluntary or involuntary termination of the
purchaser's service with the Company for any reason (including death or
disability). The purchase price for Shares repurchased pursuant to the
Restricted Stock purchase agreement shall be the original price paid by the
purchaser and may be paid by cancellation of any indebtedness of the purchaser
to the Company. The repurchase option shall lapse at such rate as the
Administrator may determine, but in no case at a rate of less than twenty
percent (20%) per year over five (5) years from the date of purchase.

  (c) Other Provisions. The Restricted Stock purchase agreement shall contain
such other terms, provisions and conditions not inconsistent with the Plan as
may be determined by the Administrator in its sole discretion.

  (d) Rights as a Shareholder. Once the Stock Purchase Right is exercised, the
purchaser shall have rights equivalent to those of a shareholder and shall be
a shareholder when his or her purchase is entered upon the records of the duly
authorized transfer agent of the Company. No adjustment shall be made for a
dividend or other right for which the record date is prior to the date the
Stock Purchase Right is exercised, except as provided in Section 15 of the
Plan.

                                       8
<PAGE>

  15. Adjustments upon Changes in Capitalization, Merger or Asset Sale.

  (a) In the event that the Administrator determines that any dividend or
other distribution (whether in the form of cash, Common Stock, other
securities, or other property), recapitalization, reclassification, stock
split, reverse stock split, reorganization, merger, consolidation, split-up,
spin-off, combination, repurchase, liquidation, dissolution, or sale,
transfer, exchange or other disposition of all or substantially all of the
assets of the Company, or exchange of Common Stock or other securities of the
Company, issuance of warrants or other rights to purchase Common Stock or
other securities of the Company, or other similar corporate transaction or
event, in the Administrator's sole discretion, affects the Common Stock such
that an adjustment is determined by the Administrator to be appropriate in
order to prevent dilution or enlargement of the benefits or potential benefits
intended to be made available under the Plan or with respect to any Option or
Stock Purchase Right, then the Administrator shall, in such manner as it may
deem equitable, adjust any or all of:

    (i) the number and kind of shares of Common Stock (or other securities or
  property) with respect to which Options or Stock Purchase Rights may be
  granted or awarded (including, but not limited to, adjustments of the
  limitations in Section 3 on the maximum number and kind of shares which may
  be issued and adjustments of the maximum number of Shares that may be
  purchased by any Optionee in any fiscal year pursuant to Section 6(c));

    (ii) the number and kind of shares of Common Stock (or other securities
  or property) subject to outstanding Options or Stock Purchase Rights; and

    (iii) the grant or exercise price with respect to any Option or Stock
  Purchase Right.

  (b) In the event of any transaction or event described in Section 15(a) or
any unusual or nonrecurring transactions or events affecting the Company, any
affiliate of the Company, or the financial statements of the Company or any
affiliate, or of changes in Applicable Laws, regulations, or accounting
principles, the Administrator, in its sole and absolute discretion, and on
such terms and conditions as it deems appropriate, either by the terms of the
Option or Stock Purchase Right or by action taken prior to the occurrence of
such transaction or event and either automatically or upon the Optionee's
request, is hereby authorized to take any one or more of the following actions
whenever the Administrator determines that such action is appropriate in order
to prevent dilution or enlargement of the benefits or potential benefits
intended to be made available under the Plan or with respect to any Option or
Stock Purchase Right granted under the Plan, to facilitate such transactions
or events or to give effect to such changes in laws, regulations or
principles:

    (i) To provide for either the purchase of any such Option or Stock
  Purchase Right for an amount of cash equal to the amount that could have
  been attained upon the exercise of such Option or Stock Purchase Right or
  realization of the Optionee's rights had such Option or Stock Purchase
  Right been currently exercisable or payable or fully vested or the
  replacement of such Option or Stock Purchase Right with other rights or
  property selected by the Administrator in its sole discretion;

    (ii) To provide that such Option or Stock Purchase Right cannot vest, be
  exercised or become payable after such event;

    (iii) To provide that such Option or Stock Purchase Right shall be
  exercisable as to all shares covered thereby, notwithstanding anything to
  the contrary in the Plan or the provisions of such Option or Stock Purchase
  Right;

    (iv) To provide that such Option or Stock Purchase Right be assumed by
  the successor or survivor corporation, or a parent or subsidiary thereof,
  or shall be substituted for by similar options, rights or awards covering
  the stock of the successor or survivor corporation, or a parent or
  subsidiary thereof, with appropriate adjustments as to the number and kind
  of shares and prices;

    (v) To make adjustments in the number and type of shares of Common Stock
  (or other securities or property) subject to outstanding Options and Stock
  Purchase Rights, and/or in the terms and conditions of (including the grant
  or exercise price), and the criteria included in, outstanding Options or
  Stock Purchase Rights or Options or Stock Purchase Rights which may be
  granted in the future; and

                                       9
<PAGE>

    (vi) To provide that, for a specified period of time prior to such event,
  the restrictions imposed under an Option Agreement or Restricted Stock
  purchase agreement upon some or all Shares may be terminated, and, in the
  case of Restricted Stock, some or all shares of such Restricted Stock may
  cease to be subject to repurchase.

  (c) Subject to Section 3, the Administrator may, in its discretion, include
such further provisions and limitations in any Option, Stock Purchase Right,
agreement or certificate, as it may deem equitable and in the best interests
of the Company.

  (d) Notwithstanding the foregoing, in the event that the Company becomes a
party to a transaction that is intended to qualify for "pooling of interests"
accounting treatment and, but for one or more of the provisions of this Plan
or any Option Agreement or any Restricted Stock purchase agreement would so
qualify, then this Plan and any such agreement shall be interpreted so as to
preserve such accounting treatment, and to the extent that any provision of
the Plan or any such agreement would disqualify the transaction from pooling
of interests accounting treatment (including, if applicable, an entire Option
Agreement or Restricted Stock purchase agreement), then such provision shall
be null and void. All determinations to be made in connection with the
preceding sentence shall be made by the independent accounting firm whose
opinion with respect to "pooling of interests" treatment is required as a
condition to the Company's consummation of such transaction.

  (e) The existence of the Plan, any Option Agreement or Restricted Stock
purchase agreement and the Options or Stock Purchase Rights granted hereunder
shall not affect or restrict in any way the right or power of the Company or
the stockholders of the Company to make or authorize any adjustment,
recapitalization, reorganization or other change in the Company's capital
structure or its business, any merger or consolidation of the Company, any
issue of stock or of options, warrants or rights to purchase stock or of
bonds, debentures, preferred or prior preference stocks whose rights are
superior to or affect the Common Stock or the rights thereof or which are
convertible into or exchangeable for Common Stock, or the dissolution or
liquidation of the company, or any sale or transfer of all or any part of its
assets or business, or any other corporate act or proceeding, whether of a
similar character or otherwise.

  16. Time of Granting Options and Stock Purchase Rights. The date of grant of
an Option or Stock Purchase Right shall, for all purposes, be the date on
which the Administrator makes the determination granting such Option or Stock
Purchase Right, or such other date as is determined by the Administrator.
Notice of the determination shall be given to each Employee or Consultant to
whom an Option or Stock Purchase Right is so granted within a reasonable time
after the date of such grant.

  17. Amendment and Termination of the Plan.

  (a) Amendment and Termination. The Board may at any time wholly or partially
amend, alter, suspend or terminate the Plan. However, without approval of the
Company's stockholders given within twelve (12) months before or after the
action by the Board, no action of the Board may, except as provided in Section
15, increase the limits imposed in Section 3 on the maximum number of Shares
which may be issued under the Plan or extend the term of the Plan under
Section 7.

  (b) Stockholder Approval. The Board shall obtain stockholder approval of any
Plan amendment to the extent necessary and desirable to comply with Applicable
Laws.

  (c) Effect of Amendment or Termination. No amendment, alteration, suspension
or termination of the Plan shall impair the rights of any Optionee, unless
mutually agreed otherwise between the Optionee and the Administrator, which
agreement must be in writing and signed by the Optionee and the Company.
Termination of the Plan shall not affect the Administrator's ability to
exercise the powers granted to it hereunder with respect to Options granted
under the Plan prior to the date of such termination.

  18. Inability to Obtain Authority. The inability of the Company to obtain
authority from any regulatory body having jurisdiction, which authority is
deemed by the Company's counsel to be necessary to the lawful

                                      10
<PAGE>

issuance and sale of any Shares hereunder, shall relieve the Company of any
liability in respect of the failure to issue or sell such Shares as to which
such requisite authority shall not have been obtained.

  19. Reservation of Shares. The Company, during the term of this Plan, shall
at all times reserve and keep available such number of Shares as shall be
sufficient to satisfy the requirements of the Plan.

  20. Stockholder Approval. This Plan was originally approved by the
Stockholders of the Company as of April 9, 1999.

  21. Information to Optionees and Purchasers. The Company shall provide to
each Optionee and to each individual who acquires Shares pursuant to the Plan,
not less frequently than annually during the period such Optionee or purchaser
has one or more Options or Stock Purchase Rights outstanding, and, in the case
of an individual who acquires Shares pursuant to the Plan, during the period
such individual owns such Shares, copies of annual financial statements. The
Company shall not be required to provide such statements to key employees
whose duties in connection with the Company assure their access to equivalent
information.

  22. Governing Law. The validity and enforceability of this Plan shall be
governed by and construed in accordance with the laws of the State of
California without regard to otherwise governing principles of conflicts of
law.

                                      11