<PAGE>
 
                                                                   EXHIBIT 10.33
                                                                                
                                            As Amended through February 12, 1996
                                            ------------------------------------


                              MARCAM CORPORATION

                     AMENDED AND RESTATED 1987 STOCK PLAN


     1.  Purpose.  This 1987 Stock Plan (the "Plan") is intended to provide
         -------                                                           
incentives:  (a) to the officers and other employees of Marcam Corporation (the
"Company"), its parent (if any) and any present or future subsidiaries of the
Company (collectively, "Related Corporations") by providing them with
opportunities to purchase stock in the Company pursuant to options granted
hereunder which qualify as "incentive stock options" under Section 422A(b) of
the Internal Revenue Code of 1986 (the "Code") ("ISO" or "ISOs"); (b) to
officers, employees and consultants of the Company and Related Corporations by
providing them with opportunities to purchase stock in the Company pursuant to
options granted hereunder which do not qualify as ISOs ("Non-Qualified Option"
or "Non-Qualified Options"); (c) to officers, employees and consultants of the
Company and Related Corporations by providing them with awards of stock in the
Company ("Awards"); and (d) to officers, employees and consultants of the
Company and Related Corporations by providing them with opportunities to make
direct purchases of stock in the Company ("Purchases").  Both ISOs and Non-
Qualified Options are referred to hereafter individually as an "Option" and
collectively as "Options".  Options, Awards and authorizations to make Purchases
are referred to hereafter collectively as "Stock Rights".  As used herein, the
terms "parent" and "subsidiary" mean "parent corporation" and "subsidiary
corporation", respectively, as those terms are defined in Section 425 of the
Code.

     2.  Administration of the Plan.
         -------------------------- 

     A.  The Plan shall be administered by the Board of Directors of the Company
   (the "Board") or by a committee appointed by the Board (the "Committee");
   provided, however, to the extent required by Rule 16b-3 (or any successor
   --------  -------
   rule to the same effect) of the Securities and Exchange Commission ("Rule 
   16b-3") under the Securities and Exchange Act of 1934, as amended (the "1934
   Act"), with respect to specific grants of Stock Rights, the Plan shall be
   administered by an administrator or administrators in compliance with Rule
   16b-3. Hereinafter all references in this Plan to the "Committee" shall mean
   the Board if no Committee has been appointed. Subject to ratification of the
   grant of each Stock Right by the Board (if so required by applicable state
   law), and subject to the terms of the Plan, the Committee shall have the
   authority to (i) determine the employees of the Company and Related
   Corporations (from among the class of employees eligible under paragraph 3 to
   receive ISOs) to whom ISOs may be granted, and to determine the individuals
   and entities (from among the class of individuals and entities eligible under
   paragraph 3 to receive Non-Qualified Options) to whom Non-
<PAGE>
 
                                      -2-

   Qualified Options may be granted or by whom Purchases may be made; (ii)
   determine the time or times at which Options or Awards may be granted; (iii)
   determine the option price of shares subject to each Option, which price with
   respect to ISOs shall not be less than the minimum specified in paragraph 6,
   and the purchase price of shares subject to each Purchase; (iv) determine
   whether each Option granted shall be an ISO or a Non-Qualified Option; (v)
   determine (subject to paragraph 7) the time or times when each Option shall
   become exercisable and the duration of the exercise period; (vi) determine
   whether restrictions such as repurchase options are to be imposed on shares
   subject to Options, Awards and Purchases and the nature of such restrictions
   if any; and (vii) interpret the Plan and prescribe and rescind rules and
   regulations relating to it. If the Committee determines to issue a Non-
   Qualified Option, it shall take whatever actions it deems necessary, under
   Section 422A of the Code and the regulations promulgated thereunder, to
   ensure that such Option is not treated as an ISO. The interpretation and
   construction by the Committee of any provisions of the Plan or of any Stock
   Right granted under it shall be final unless otherwise determined by the
   Board. The Committee may from time to time adopt such rules and regulations
   for carrying out the Plan as it may deem best. No member of the Board or the
   Committee shall be liable for any action or determination made in good faith
   with respect to the Plan or any Stock Right granted under it.

     B.  The Committee may select one of its members as its chairman, and shall
   hold meetings at such time and places as it may determine. Acts by a majority
   of the Committee, or acts reduced to or approved in writing by a majority of
   the members of the Committee, shall be the valid acts of the Committee. All
   references in this Plan to the Committee shall mean the Board if no Committee
   has been appointed. From time to time the Board may increase the size of the
   Committee and appoint additional members thereof, remove members (with or
   without cause) and appoint new members in substitution therefor, fill
   vacancies however caused, or remove all members of the Committee and
   thereafter directly administer the Plan.

     3.  Eligible Employees and Others.  ISOs may be granted to any employee of
         -----------------------------                                         
the Company or any Related Corporation.  Those officers of the Company who are
not employees may not be granted ISOs under the Plan.  Non-Qualified Options,
Awards and authorizations to make Purchases may be granted to any officer,
employee or consultant of the Company or any Related Corporation.  Those
directors of the Company who are not employees of the Company shall not be
eligible to receive Stock Rights under this Plan.  The Committee may take into
consideration a recipient's individual circumstances in determining whether to
grant an ISO, a Non-Qualified Option or an authorization to make a Purchase.
Granting of any Stock Right to any individual or entity shall neither entitle
that individual or entity to, nor disqualify him from, participation in any
other grant of Stock Rights.

     4.  Stock.  The stock subject to Options, Awards and Purchases shall be
         -----                                                              
authorized but unissued shares of Common Stock of the Company, par value $.01
per 
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                                      -3-

share (the "Common Stock"), or shares of Common Stock reacquired by the Company
in any manner. The aggregate number of shares which may be issued pursuant to
the Plan is 1,750,000 subject to adjustment as provided in paragraph 13. Any
such shares may be issued as ISOs, Non-Qualified Options or Awards, or to
persons or entities making Purchases, so long as the number of shares so issued
does not exceed such number, as adjusted. If any Option granted under the Plan
shall expire or terminate for any reason without having been exercised in full
or shall cease for any reason to be exercisable in whole or in part, or if the
Company shall reacquire any unvested shares issued pursuant to Awards or
Purchases, the unpurchased shares subject to such Options and any unvested
shares so reacquired by the Company shall again be available for grants of Stock
Rights under the Plan.

     5.  Granting of Stock Rights.  Stock Rights may be granted under the Plan
         ------------------------                                             
at any time on and after July 31, 1987 and prior to December 31, 1996.  The date
of grant of a Stock Right under the Plan will be the date specified by the
Committee at the time it grants the Stock Right; provided, however, that such
date shall not be prior to the date on which the Committee acts to approve the
grant.  The Committee shall have the right, with the consent of the optionee, to
convert an ISO granted under the Plan to a Non-Qualified Option pursuant to
paragraph 16.

     6.  Minimum Option Price; ISO Limitations.
         ------------------------------------- 

     A.  The price per share specified in the agreement relating to each ISO
   granted under the Plan shall not be less than the fair market value per share
   of Common Stock on the date of such grant.  In the case of an ISO to be
   granted to an employee owning stock possessing more than ten percent of the
   total combined voting power of all classes of stock of the Company or any
   Related Corporation, the price per share specified in the agreement relating
   to such ISO shall not be less than 110 percent of the fair market value per
   or share of Common Stock on the date of grant.

     B.  Each eligible employee may be granted ISOs only to the extent that, in
   the aggregate under this Plan and all incentive stock option plans of the
   Company and any Related Corporation, such ISOs do not become exercisable for
   the first time by such employee during any calendar year in a manner which
   would entitle the employee to purchase more than $100,000 in fair market
   value (determined at the time the ISOs were granted) of Common Stock in that
   year.  Any options granted to an employee in excess of such amount will be
   granted as Non-Qualified Options.

     C.  If, at the time an Option is granted under the Plan, the Company's
   Common Stock is publicly traded, "fair market value" shall be determined as
   of the last business day for which the prices or quotes discussed in this
   sentence are available prior to the date such Option is granted and shall
   mean (i) the average (on that date) of the high and low prices of the Common
   Stock on the principal national securities exchange on which the Common Stock
   is traded, if the Common Stock is then traded 
<PAGE>
 
                                      -4-

   on a national securities exchange; or (ii) the last reported sale price (on
   that date) of the Common Stock on the NASDAQ National Market List, if the
   Common Stock is not then traded on a national securities exchange; or (iii)
   the closing bid price (or average of bid prices) last quoted (on that date)
   by an established quotation service for over-the-counter securities, if the
   Common Stock is not reported on the NASDAQ National Market List. However, if
   the Common Stock is not publicly traded at the time an Option is granted
   under the Plan, "fair market value" shall be deemed to be the fair value of
   the Common Stock as determined by the Committee after taking into
   consideration all factors which it deems appropriate, including, without
   limitation, recent sale and offer prices of the Common Stock in private
   transactions negotiated at arm's length.

     7.  Option Duration.  Subject to earlier termination as provided in
         ---------------                                                
paragraphs 9 and 10, each Option shall expire on the date specified by the
Committee, but not more than (i) ten years and one day from the date of grant in
the case of Non-Qualified Options, (ii) ten years from the date of grant in the
case of ISOs generally, and (iii) five years from the date of grant in the case
of ISOs granted to an employee owning stock possessing more than ten percent of
the total combined voting power of all classes of stock of the Company or any
Related Corporation.  Subject to earlier termination as provided in paragraphs 9
and 10, the term of each ISO shall be the term set forth in the original
instrument granting such ISO, except with respect to any part of such ISO that
is converted into a Non-Qualified Option pursuant to paragraph 16.

     8.  Exercise of Option.  Subject to the provisions of paragraphs 9 through
         ------------------                                                    
12, each Option granted under the Plan shall be exercisable as follows:

     A.  The Option shall either be fully exercisable on the date of grant or
   shall become exercisable thereafter in such installments as the Committee may
   specify.

     B.  Once an installment becomes exercisable it shall remain exercisable
   until expiration or termination of the Option, unless otherwise specified by
   the Committee.

     C.  Each Option or installment may be exercised at any time or from time to
   time, in whole or in part, for up to the total number of shares with respect
   to which it is then exercisable.

     D.  The Committee shall have the right to accelerate the date of exercise
   of any installment of any Option; provided that the Committee shall not,
   without the consent of an employee, accelerate the exercise date of any
   installment of any Option granted to the employee as an ISO (and not
   previously converted into a Non-Qualified Option pursuant to paragraph 16) if
   such acceleration would violate the annual vesting limitation contained in
   Section 422A(d) of the Code, as described in paragraph 6(B).
<PAGE>
 
                                      -5-

     E.  In the event of a Change in Control (as hereinafter defined) of the
   Company, the date on which all outstanding Stock Rights and all installments
   of such Stock Rights may be exercised shall be accelerated to immediately
   prior to the time of the Change in Control.

     F.  For purposes of this Plan and any Stock Rights granted hereunder, a
   "Change in Control" shall have occurred if at any time any of the following
   events shall occur:

               (i)    The Company is merged, consolidated or reorganized into or
       with another corporation or other legal person, and as a result of such
       merger, consolidation or reorganization less than a majority of the
       combined voting power of the then-outstanding securities of the combined
       corporation or person immediately after such transaction are held in the
       aggregate by the holders of the combined voting power of the then-
       outstanding securities entitled to vote generally in the election of
       directors of the Company ("Voting Stock") immediately prior to such
       transaction;

               (ii)   The Company sells or otherwise transfers all or
       substantially all of its assets to any other corporation or other legal
       person, and less than a majority of the combined voting power of the
       then-outstanding securities of such corporation or person immediately
       after such sale or transfer is held in the aggregate by the holders of
       the Voting Stock of the Company immediately prior to such sale or
       transfer;

               (iii)  There is a report filed on Schedule 13D or Schedule 14D-1
       (or any successor schedule, form or report), each as promulgated pursuant
       to the 1934 Act, disclosing that any person (as the term "person" is used
       in Section 13(d)(3) or Section 14(d)(2) or the 1934 Act) has become the
       beneficial owner (as the term "beneficial owner" is defined under Rule
       13d-3 or any successor rule or regulation promulgated under the 1934 Act)
       of securities representing 25% or more of the Voting Stock;

               (iv)   The Company files a report or proxy statement with the
       Securities and Exchange Commission pursuant to the 1934 Act disclosing in
       response to Form 8-K or Schedule 14A (or any successor schedule, form or
       report or item therein) that a change in control of the Company has or
       may have occurred or will or may occur in the future pursuant to any
       then-existing contract or transaction; or

               (v)    If during any period of two consecutive years, individuals
       who at the beginning of any such period constitute the directors of the
       Company cease for any reason to constitute at least a majority thereof,
       unless the election, or the nomination for election by the Company's
       stockholders, of each director of the Company first elected during such
       period was approved by a 
<PAGE>
 
                                      -6-

       vote of at least two-thirds of the directors then still in office who
       were directors of the Company at the beginning of any such period;

   provided, however, that notwithstanding the foregoing provisions of this
   -----------------                                                       
   subparagraph F, a "Change in Control" shall not be deemed to have occurred
   for purposes of this Plan solely because (i) the Company, (ii) an entity in
   which the Company directly or indirectly beneficially owns 50% or more of the
   voting securities, (iii) any Company-sponsored employee stock ownership plan
   any other employee benefit plan of the Company, or (iv) any corporation or
   legal person approved by the Board prior to the occurrence of the event that,
   absent such approval by the Board, would have constituted a Change in
   Control, either files or becomes obligated to file a report or a proxy
   statement under or in response to Schedule 13D, Schedule 14D-1, Form 8-K or
   Schedule 14A (or any successor schedule, form or report or item therein)
   under the 1934 Act, disclosing beneficial ownership by it of shares of Voting
   Stock, whether in excess of 25% or otherwise, or because the Company reports
   that a change in control of the Company has or may have occurred or will or
   may occur in the future by reason of such beneficial ownership.

     9.  Termination of Employment.  If an ISO optionee ceases to be employed by
         -------------------------                                              
the Company and all Related Corporations other than by reason of death or
disability as defined in paragraph 10, no further installments of his ISOs shall
become exercisable, and his ISOs shall terminate after the passage of 60 days
from the date of termination of his employment, but in no event later than on
their specified expiration dates, except to the extent that such ISOs (or
unexercised installments thereof) have been converted into Non-Qualified Options
pursuant to paragraph 16.  Employment shall be considered as continuing
uninterrupted during any bona fide leave of absence (such as those attributable
to illness, military obligations or governmental service) provided that the
period of such leave does not exceed 90 days or, if longer, any period during
which such optionee's right to reemployment is guaranteed by statute.  A bona
fide leave of absence with the written approval of the Committee shall not be
considered an interruption of employment under the Plan, provided that such
written approval contractually obligates the Company or any Related Corporation
to continue the employment of the optionee after the approved period of absence.
ISOs granted under the Plan shall not be affected by any change of employment
within or among the Company and Related Corporations, so long as the optionee
continues to be an employee of the Company or any Related Corporation.  Nothing
in the Plan shall be deemed to give any grantee of any Stock Right the right to
be retained in employment or other service by the Company or any Related
Corporation for any period of time.

     10. Death; Disability.
         ----------------- 

     A.  If an ISO optionee ceases to be employed by the Company and all Related
   Corporations by reason of his death, any ISO of his may be exercised, to the
   extent of the number of shares with respect to which he could have exercised
   it on the date 
<PAGE>
 
                                      -7-

   of his death, by his estate, personal representative or beneficiary who has
   acquired the ISO by will or by the laws of descent and distribution, at any
   time prior to the earlier of the ISO's specified expiration date or 180 days
   from the date of the optionee's death.

     B.  If an ISO optionee ceases to be employed by the Company and all Related
   Corporations by reason of his disability, he shall have the right to exercise
   any ISO held by him on the date of termination of employment, to the extent
   of the number of shares with respect to which he could have exercised it on
   that date, at any time prior to the earlier of the ISO's specified expiration
   date or 180 days from the date of the termination of the optionee's
   employment.  For the purposes of the Plan, the term "disability" shall mean
   "permanent and total disability" as defined in Section 22(e)(3) of the Code
   or successor statute.

     11. Assignability.  No Stock Right shall be assignable or transferable by
         -------------                                                        
the optionee except by will or by the laws of descent or distribution or, with
respect to Non-Qualified Options, pursuant to a qualified domestic relations
order as defined in the Code or Title I of the Employee Retirement Income
Security Act, or the rules thereunder.  During the lifetime of the optionee each
Stock Right shall be exercisable only by him.

     12. Terms and Conditions of Options.  Options shall be evidenced by
         -------------------------------                                
instruments (which need not be identical) in such forms as the Committee may
from time to time approve.  Such instruments shall conform to the terms and
conditions set forth in paragraphs 6 through 11 hereof and may contain such
other provisions as the Committee deems advisable which are not inconsistent
with the Plan, including restrictions applicable to shares of Common Stock
issuable upon exercise of Options.  In granting any Non-Qualified Option, the
Committee may specify that such Non-Qualified Option shall be subject to the
restrictions set forth herein with respect to ISOs, or to such other termination
and cancellation provisions as the Committee may determine.  The Committee may
from time to time confer authority and responsibility on one or more of its own
members and/or one or more officers of the Company to execute and deliver such
instruments.  The proper officers of the Company are authorized and directed to
take any and all action necessary or advisable from time to time to carry out
the terms of such instruments.

     13. Adjustments.  Upon the occurrence of any of the following events, any
         -----------                                                          
Stock Right granted to a holder hereunder shall be adjusted as hereinafter
provided, unless otherwise specifically provided in the written agreement
between such holder and the Company relating to such Stock Rights:

     A.  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 a Stock
   Right shall be appropriately increased or decreased proportionately, and
   appropriate adjustments 
<PAGE>
 
                                      -8-

   shall be made in the purchase price per share to reflect such subdivision,
   combination or stock dividend.

     B.  In the event of a Change in Control  of the Company and subject to
   Section 8(E) hereof, the Committee shall, as to all outstanding Stock Rights,
   either (i) make appropriate provision for the continuation of such Stock
   Rights by substituting on an equitable basis for the shares then subject to
   such Stock Rights the consideration payable with respect to the outstanding
   shares of Common Stock in connection with the Change in Control, (ii) upon
   written notice to the holders of such Stock Rights, provide that all Stock
   Rights must be exercised within a specified number of days (which shall not
   be less than 30 days) of the date of such notice, at the end of which period
   the Stock Rights shall terminate, or (iii) terminate all Stock Rights in
   exchange for a cash payment equal to the excess of the fair market value of
   the shares subject to such Stock Rights over the exercise price thereof.

     C.  If the Company is merged, consolidated or reorganized into or with
   another corporation or other legal person, or if the Company sells or
   otherwise transfers all or substantially all of its assets to any other
   corporation or other legal person, pursuant to which securities of the
   Company or of another corporation, cash or other property are issued with
   respect to the outstanding shares of Common Stock, and such transaction does
   not constitute a Change in Control, a holder of a Stock Right upon exercising
   a Stock Right shall be entitled to receive for the purchase price paid upon
   such exercise the securities, cash or other property he would have received
   if he had exercised his Stock Right prior to such merger, consolidation,
   reorganization or sale.

     D.  Notwithstanding the foregoing, any adjustments made pursuant to
   subparagraphs A, B or C with respect to ISOs shall be made only after the
   Committee, after consulting with counsel for the Company, determines whether
   such adjustments would constitute a "modification" of such ISOs (as that term
   is defined in Section 424 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 an ISO would constitute a modification
   of such ISO, it shall refrain from making such adjustments without the
   consent of the holder of such ISO.

     E.  In the event of the proposed dissolution or liquidation of the Company,
   each Stock Right will terminate immediately prior to the consummation of such
   proposed action or at such other time and subject to such other conditions as
   shall be determined by the Committee.

     F.  Except as expressly provided herein, no issuance 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 Stock Rights.  No
   adjustments shall be made for dividends paid in cash or in property other
   than securities of the Company.
<PAGE>
 
                                      -9-

     G.  No fractional shares shall be issued under the Plan and the optionee
   shall receive from the Company cash in lieu of such fractional shares.

     H.  Upon the happening of any of the foregoing events described in
   subparagraphs A, B or C above, the class and aggregate number of shares set
   forth in paragraph 4 hereof that are subject to Stock Rights which previously
   have been or subsequently may be granted under the Plan shall also be
   appropriately adjusted to reflect the events described in such subparagraphs.
   The Committee shall determine the specific adjustments to be made under this
   paragraph 13 and, subject to paragraph 2, its determination shall be
   conclusive.

     I.  If any person or entity owning restricted Common Stock obtained by
   exercise of a Stock Right made hereunder receives shares, securities or cash
   in connection with a corporate transaction described in subparagraphs A, B or
   C above as a result of owning such restricted Common Stock, such shares,
   securities or cash shall be subject to all of the conditions and restrictions
   applicable to the restricted Common Stock with respect to which such shares
   or securities or cash were issued, unless otherwise determined by the
   Committee.

   14.   Means of Exercising Stock Rights.  A Stock Right (or any part or
         --------------------------------                                
installment thereof) shall be exercised by giving written notice to the Company
at its principal office address.  Such notice shall identify the Stock Right
being exercised and specify the number of shares as to which such Stock Right is
being exercised, accompanied by full payment of the purchase price therefor
either (a) in United States dollars in cash or by check, or (b) at the
discretion of the Committee, through delivery of shares of Common Stock having a
fair market value equal as of the date of the exercise to the cash exercise
price of the Stock Right, or (c) at the discretion of the Committee, by delivery
of the grantee's personal recourse note bearing interest payable not less than
annually at no less than 100% of the lowest applicable Federal rate, as defined
in Section 1274(d) of the Code, or (d) at the discretion of the Committee, by
any combination of (a), (b) and (c) above.  If the Committee exercises its
discretion to permit payment of the exercise price of an ISO by means of the
methods set forth in clauses (b), (c), or (d) of the preceding sentence, such
discretion shall be exercised in writing at the time of the grant of the ISO in
question.  The holder of a Stock Right shall not have the rights of a
shareholder with respect to the shares covered by his Stock Right until the date
of issuance of a stock certificate to him for such shares.  Except as expressly
provided above in paragraph 13 with respect to changes in capitalization and
stock dividends, no adjustment shall be made for dividends or similar rights for
which the record date is before the date such stock certificate is issued.

   15.   Term and Amendment of Plan.  This Plan was adopted by the Board on
         --------------------------                                        
July 31, 1987 and by the stockholders of the Company on March 29, 1988.  The
Plan shall expire on December 31, 1996 (except as to Options outstanding on that
date).  Subject to the provisions of paragraph 5 above, Stock Rights may be
granted under the Plan prior to 
<PAGE>
 
                                      -10-

the date of stockholder approval of the Plan. The Board may terminate or amend
the Plan in any respect at any time, except that, without the approval of the
stockholders obtained within 12 months before or after the Board adopts a
resolution authorizing any of the following actions: (a) the total number of
shares that may be issued under the Plan may not be increased (except by
adjustment pursuant to paragraph 13); (b) the provisions of paragraph 3
regarding eligibility for grants of ISOs may not be modified; (c) the provisions
of paragraph 6(B) regarding the exercise price at which shares may be offered
pursuant to ISOs may not be modified (except by adjustment pursuant to paragraph
13); (d) the expiration date of the Plan may not be extended; and (e) the Plan
may not be amended in any manner which causes Rule 16b-3 under the 1934 Act to
become inapplicable to the Plan. Except as provided in the fourth sentence of
this paragraph 15, in no event may action of the Board or Stockholders alter or
impair the rights of a grantee, without his consent, under any Stock Right
previously granted to him.

     16. Conversion of ISOs into Non-Qualified Options; Termination of ISOs.
         ------------------------------------------------------------------  
The Committee, at the written request of any optionee, may in its discretion
take such actions as may be necessary to convert such optionee's ISOs (or any
installments or portions of installments thereof) that have not been exercised
on the date of conversion into Non-Qualified Options at any time prior to the
expiration of such ISOs, regardless of whether the optionee is an employee of
the Company or a Related Corporation 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 optionee)
may impose such conditions on the exercise of the resulting Non-Qualified
Options 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 optionee the right to have such optionee's ISOs converted
into Non-Qualified Options, and no such conversion shall occur until and unless
the Committee takes appropriate action.  The Committee, with the consent of the
optionee, may also terminate any portion of any ISO that has not been exercised
at the time of such termination.

     17. Application of Funds.  The proceeds received by the Company from the
         --------------------                                                
sale of shares pursuant to Options granted and Purchases authorized under the
Plan shall be used for general corporate purposes.

     18. Governmental Regulation.  The Company's obligation to sell and deliver
         -----------------------                                               
shares of the Common Stock under this Plan is subject to the approval of any -
governmental authority required in connection with the authorization, issuance
or sale of such shares.

     19. Withholding of Additional Income Taxes.  Upon the exercise of a Non-
         --------------------------------------                             
Qualified Option, the grant of an Award, the making of a Purchase of Common
Stock for less than its fair market value, the making of a Disqualifying
Disposition (as defined in paragraph 20) or the vesting of restricted Common
Stock acquired on the exercise of a Stock Right hereunder, the Company, in
accordance with Section 3402(a) of the Code, 
<PAGE>
 
                                      -11-

may require the optionee, Award recipient or purchaser to pay additional
withholding taxes in respect of the amount that is considered compensation
includible in such person's gross income. The Committee in its discretion may
condition (i) the exercise of an Option, (ii) the grant of an Award, (iii) the
making of a Purchase of Common Stock for less than its fair market value, or
(iv) the vesting of restricted Common Stock acquired by exercising a Stock Right
on the grantee's payment of such additional withholding taxes.

     20. Notice to Company of Disqualifying Disposition.  Each employee who
         ----------------------------------------------                    
receives an ISO must agree to notify the Company in writing immediately after
the employee makes a Disqualifying Disposition of any Common Stock acquired
pursuant to the exercise of an ISO.  A Disqualifying Disposition is any
disposition (including any sale) of such Common Stock before the later of (a)
two years after the date the employee was granted the ISO or (b) one year after
the date the employee acquired Common Stock by exercising the ISO.  If the
employee has died before such stock is sold, these holding period requirements
do not apply and no Disqualifying Disposition can occur thereafter.

     21. Governing Law; Construction.  The validity and construction of the
         ---------------------------                                       
Plan and the instruments evidencing Stock Rights shall be governed by the laws
of The Commonwealth of Massachusetts.  In construing this Plan, the singular
shall include the plural and the masculine gender shall include the feminine and
neuter, unless the context otherwise requires.


Dates Amended by Board of Directors:    July 30, 1991
                                        November 6, 1991
                                        November 3, 1992
                                        February 12, 1996

Dates Amended by Stockholders:  February 11, 1993