<PAGE>


EXHIBIT 10.13 

FORTE SOFTWARE, INC. NOTICE OF STOCK OPTION GRANT


     You have been granted the following option to purchase Common Stock of 
Forte Software, Inc. (the "Company"):

          Name of Optionee:                Thomas A. Jermoluk

          Total Number of Shares Granted:  3,000

          Type of Option:                  Nonstatutory Stock Option

          Exercise Price Per Share:        $15.0625

          Date of Grant:                   September 12, 1997

          Date Exercisable:                No part of this option may be
                                           exercised prior to September
                                           12, 1998.  This option may be
                                           exercised for all or any part
                                           of the Shares subject to this
                                           option at any time on or after
                                           September 12, 1998.


         Expiration Date:                  September 11, 2007

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

OPTIONEE:                                  FORTE SOFTWARE, INC.

                                           By:
----------------------------------------      --------------------------------
Thomas A. Jermoluk                         Title:
                                                 -----------------------------

<PAGE>

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

                        FORTE SOFTWARE, INC.
                       STOCK OPTION AGREEMENT


GRANT OF OPTION.


OPTION.  ON THE TERMS AND CONDITIONS SET FORTH IN THE NOTICE OF STOCK OPTION 
GRANT AND THIS AGREEMENT, THE COMPANY GRANTS TO THE OPTIONEE ON THE DATE OF 
GRANT THE OPTION TO PURCHASE AT THE EXERCISE PRICE THE NUMBER OF SHARES SET 
FORTH IN THE NOTICE OF STOCK OPTION GRANT.  THE EXERCISE PRICE IS AGREED TO 
BE 100% OF THE FAIR MARKET VALUE PER SHARE ON THE DATE OF GRANT.  THIS OPTION 
IS INTENDED TO BE A NONSTATUTORY OPTION, AS PROVIDED IN THE NOTICE OF STOCK 
OPTION GRANT.

DEFINED TERMS.  CAPITALIZED TERMS ARE DEFINED IN SECTION 12 OF THIS AGREEMENT.

RIGHT TO EXERCISE.

GENERAL RULE.  SUBJECT TO THE CONDITIONS SET FORTH IN THIS AGREEMENT, ALL OR 
PART OF THIS OPTION MAY BE EXERCISED PRIOR TO ITS EXPIRATION AT THE TIME OR 
TIMES SET FORTH IN THE NOTICE OF STOCK OPTION GRANT.  THIS OPTION SHALL NOT 
BECOME EXERCISABLE WITH RESPECT TO ANY ADDITIONAL SHARES AFTER THE OPTIONEE'S 
SERVICE HAS TERMINATED FOR ANY REASON.

ACCELERATED EXERCISABILITY.  THIS OPTION SHALL BECOME EXERCISABLE IN FULL IF 
THE COMPANY IS SUBJECT TO A CHANGE IN CONTROL BEFORE THE OPTIONEE'S SERVICE 
TERMINATES.  THE PRECEDING SENTENCE, HOWEVER, SHALL NOT APPLY TO THE EXTENT 
THAT, IN CONNECTION WITH THE CHANGE IN CONTROL, THIS OPTION:

REMAINS OUTSTANDING;

IS ASSUMED BY THE SUCCESSOR CORPORATION (OR ITS PARENT);

IS REPLACED WITH A COMPARABLE OPTION TO PURCHASE SHARES OF THE CAPITAL STOCK 
OF THE SUCCESSOR CORPORATION (OR ITS PARENT); OR

IS REPLACED WITH A CASH INCENTIVE PROGRAM OF THE SUCCESSOR CORPORATION (OR 
ITS PARENT) THAT 

<PAGE>

(A) PRESERVES THE EXCESS OF THE FAIR MARKET VALUE OF THE SHARES SUBJECT TO 
THIS OPTION OVER THE EXERCISE PRICE AND (B) PROVIDES FOR A SUBSEQUENT PAYOUT 
OF SUCH EXCESS IN ACCORDANCE WITH THE EXERCISABILITY SCHEDULE SET FORTH IN 
THE NOTICE OF STOCK OPTION GRANT.

The Board of Directors shall determine whether an option to purchase shares 
of the capital stock of the successor corporation (or its parent) is 
comparable to this option.  The Board of Directors shall also determine 
whether a cash incentive program of the successor corporation (or its parent) 
meets the foregoing requirements.  The determinations of the Board of 
Directors shall be final and binding.

NO TRANSFER OR ASSIGNMENT OF OPTION.

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

<PAGE>

EXERCISE PROCEDURES.

NOTICE OF EXERCISE.  THE OPTIONEE OR THE OPTIONEE'S REPRESENTATIVE MAY 
EXERCISE THIS OPTION BY GIVING WRITTEN NOTICE TO THE COMPANY PURSUANT TO 
SECTION 11(b).  THE NOTICE SHALL SPECIFY THE ELECTION TO EXERCISE THIS 
OPTION, THE NUMBER OF SHARES FOR WHICH IT IS BEING EXERCISED AND THE FORM OF 
PAYMENT.  THE NOTICE SHALL BE SIGNED BY THE PERSON EXERCISING THIS OPTION.  
IN THE EVENT THAT THIS OPTION IS BEING EXERCISED BY THE REPRESENTATIVE OF THE 
OPTIONEE, THE NOTICE SHALL BE ACCOMPANIED BY PROOF (SATISFACTORY TO THE 
COMPANY) OF THE REPRESENTATIVE'S RIGHT TO EXERCISE THIS OPTION.  THE OPTIONEE 
OR THE OPTIONEE'S REPRESENTATIVE SHALL DELIVER TO THE COMPANY, AT THE TIME OF 
GIVING THE NOTICE, PAYMENT IN A FORM PERMISSIBLE UNDER SECTION 5 FOR THE FULL 
AMOUNT OF THE PURCHASE PRICE.

ISSUANCE OF SHARES.  AFTER RECEIVING A PROPER NOTICE OF EXERCISE, THE COMPANY 
SHALL CAUSE TO BE ISSUED A CERTIFICATE OR CERTIFICATES FOR THE SHARES AS TO 
WHICH THIS OPTION HAS BEEN EXERCISED, REGISTERED IN THE NAME OF THE PERSON 
EXERCISING THIS OPTION (OR IN THE NAMES OF SUCH PERSON AND HIS OR HER SPOUSE 
AS COMMUNITY PROPERTY OR AS JOINT TENANTS WITH RIGHT OF SURVIVORSHIP).  THE 
COMPANY SHALL CAUSE SUCH CERTIFICATE OR CERTIFICATES TO BE DELIVERED TO OR 
UPON THE ORDER OF THE PERSON EXERCISING THIS OPTION.

WITHHOLDING TAXES.  IN THE EVENT THAT THE COMPANY DETERMINES THAT IT IS 
REQUIRED TO WITHHOLD ANY TAX AS A RESULT OF THE EXERCISE OF THIS OPTION, THE 
OPTIONEE, AS A CONDITION TO THE EXERCISE OF THIS OPTION, SHALL MAKE 
ARRANGEMENTS SATISFACTORY TO THE COMPANY TO ENABLE IT TO SATISFY ALL 
WITHHOLDING REQUIREMENTS.  THE OPTIONEE SHALL ALSO MAKE ARRANGEMENTS 
SATISFACTORY TO THE COMPANY TO ENABLE IT TO SATISFY ANY WITHHOLDING 
REQUIREMENTS THAT MAY ARISE IN CONNECTION WITH THE DISPOSITION OF SHARES 
PURCHASED BY EXERCISING THIS OPTION.

PAYMENT FOR STOCK.

CASH.  ALL OR PART OF THE PURCHASE PRICE MAY BE PAID IN CASH OR CASH 
EQUIVALENTS.

SURRENDER OF STOCK.  ALL OR ANY PART OF THE PURCHASE PRICE MAY BE PAID BY 
SURRENDERING, OR ATTESTING TO THE OWNERSHIP OF, SHARES THAT ARE ALREADY OWNED 
BY THE OPTIONEE.  SUCH SHARES SHALL BE SURRENDERED TO THE COMPANY IN GOOD 
FORM FOR TRANSFER AND SHALL BE VALUED AT THEIR FAIR MARKET VALUE ON THE DATE 
WHEN THIS OPTION IS EXERCISED.  THE OPTIONEE SHALL NOT SURRENDER, OR ATTEST 
TO THE OWNERSHIP OF, SHARES IN PAYMENT OF THE PURCHASE PRICE IF SUCH ACTION 
WOULD CAUSE THE COMPANY TO RECOGNIZE COMPENSATION EXPENSE (OR ADDITIONAL 
COMPENSATION EXPENSE) WITH RESPECT TO THIS OPTION FOR FINANCIAL REPORTING 
PURPOSES.

EXERCISE/SALE.  ALL OR PART OF THE PURCHASE PRICE AND ANY WITHHOLDING TAXES 
MAY BE PAID BY THE DELIVERY (ON A FORM PRESCRIBED BY THE COMPANY) OF AN 
IRREVOCABLE DIRECTION TO A SECURITIES BROKER APPROVED BY THE COMPANY TO SELL 
SHARES AND TO DELIVER ALL OR PART OF THE SALES PROCEEDS TO THE COMPANY.

<PAGE>

EXERCISE/PLEDGE.  ALL OR PART OF THE PURCHASE PRICE AND ANY WITHHOLDING TAXES 
MAY BE PAID BY THE DELIVERY (ON A FORM PRESCRIBED BY THE COMPANY) OF AN 
IRREVOCABLE DIRECTION TO PLEDGE SHARES TO A SECURITIES BROKER OR LENDER 
APPROVED BY THE COMPANY, AS SECURITY FOR A LOAN, AND TO DELIVER ALL OR PART 
OF THE LOAN PROCEEDS TO THE COMPANY.

TERM AND EXPIRATION.

BASIC TERM.  THIS OPTION SHALL IN ANY EVENT EXPIRE ON THE EXPIRATION DATE SET 
FORTH IN THE NOTICE OF STOCK OPTION GRANT, WHICH DATE IS 10 YEARS AFTER THE 
DATE OF GRANT.

TERMINATION OF SERVICE (EXCEPT BY DEATH).  IF THE OPTIONEE'S SERVICE 
TERMINATES FOR ANY REASON OTHER THAN DEATH, THEN THIS OPTION SHALL EXPIRE ON 
THE EARLIEST OF THE FOLLOWING OCCASIONS:

THE EXPIRATION DATE DETERMINED PURSUANT TO SUBSECTION (a) ABOVE;

THE DATE THREE MONTHS AFTER THE TERMINATION OF THE OPTIONEE'S SERVICE FOR ANY 
REASON OTHER THAN DISABILITY; OR

THE DATE 12 MONTHS AFTER THE TERMINATION OF THE OPTIONEE'S SERVICE BY REASON 
OF DISABILITY. 

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

DEATH OF THE OPTIONEE.  IF THE OPTIONEE DIES WHILE IN SERVICE, THEN THIS 
OPTION SHALL EXPIRE ON THE EARLIER OF THE FOLLOWING DATES:

THE EXPIRATION DATE DETERMINED PURSUANT TO SUBSECTION (a) ABOVE; OR

THE DATE 12 MONTHS AFTER THE OPTIONEE'S DEATH.

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

<PAGE>

LEGALITY OF INITIAL ISSUANCE.

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

IT AND THE OPTIONEE HAVE TAKEN ANY ACTIONS REQUIRED TO REGISTER THE SHARES 
UNDER THE SECURITIES ACT OR TO PERFECT AN EXEMPTION FROM THE REGISTRATION 
REQUIREMENTS THEREOF;

ANY APPLICABLE LISTING REQUIREMENT OF ANY STOCK EXCHANGE OR OTHER SECURITIES 
MARKET ON WHICH STOCK IS LISTED HAS BEEN SATISFIED; AND

ANY OTHER APPLICABLE PROVISION OF STATE OR FEDERAL LAW HAS BEEN SATISFIED.

NO REGISTRATION RIGHTS.

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

RESTRICTIONS ON TRANSFER.

SECURITIES LAW RESTRICTIONS.  REGARDLESS OF WHETHER THE OFFERING AND SALE OF 
SHARES UNDER THIS OPTION HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OR 
HAVE BEEN REGISTERED OR QUALIFIED UNDER THE SECURITIES LAWS OF ANY STATE, THE 
COMPANY AT ITS DISCRETION MAY IMPOSE RESTRICTIONS UPON THE SALE, PLEDGE OR 
OTHER TRANSFER OF SUCH SHARES (INCLUDING THE PLACEMENT OF APPROPRIATE LEGENDS 
ON STOCK CERTIFICATES OR THE IMPOSITION OF STOP-TRANSFER INSTRUCTIONS) IF, IN 
THE JUDGMENT OF THE COMPANY, SUCH RESTRICTIONS ARE NECESSARY OR DESIRABLE IN 
ORDER TO ACHIEVE COMPLIANCE WITH THE SECURITIES ACT, THE SECURITIES LAWS OF 
ANY STATE OR ANY OTHER LAW.

INVESTMENT INTENT AT GRANT.  THE OPTIONEE REPRESENTS AND AGREES THAT THE 
SHARES TO BE ACQUIRED UPON EXERCISING THIS OPTION WILL BE ACQUIRED FOR 
INVESTMENT, AND NOT WITH A VIEW TO THE SALE OR DISTRIBUTION THEREOF.

INVESTMENT INTENT AT EXERCISE.  IN THE EVENT THAT THE SALE OF SHARES UNDER 
THIS OPTION IS NOT REGISTERED UNDER THE SECURITIES ACT BUT AN EXEMPTION IS 
AVAILABLE WHICH REQUIRES AN INVESTMENT REPRESENTATION OR OTHER 
REPRESENTATION, THE OPTIONEE SHALL REPRESENT AND AGREE AT THE TIME OF 
EXERCISE THAT THE SHARES BEING ACQUIRED UPON EXERCISING THIS OPTION ARE BEING 
ACQUIRED FOR INVESTMENT, AND NOT WITH A VIEW TO THE SALE OR DISTRIBUTION 
THEREOF, AND SHALL MAKE SUCH OTHER REPRESENTATIONS AS ARE DEEMED NECESSARY OR 
APPROPRIATE BY THE COMPANY AND ITS COUNSEL.

LEGENDS.  ALL CERTIFICATES EVIDENCING SHARES PURCHASED UNDER THIS AGREEMENT 
IN AN UNREGISTERED TRANSACTION SHALL BEAR THE FOLLOWING LEGEND (AND SUCH 
OTHER RESTRICTIVE LEGENDS AS ARE REQUIRED OR DEEMED ADVISABLE UNDER THE 
PROVISIONS OF ANY APPLICABLE LAW): 

<PAGE>

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

REMOVAL OF LEGENDS.  IF, IN THE OPINION OF THE COMPANY AND ITS COUNSEL, ANY 
LEGEND PLACED ON A STOCK CERTIFICATE REPRESENTING SHARES SOLD UNDER THIS 
AGREEMENT IS NO LONGER REQUIRED, THE HOLDER OF SUCH CERTIFICATE SHALL BE 
ENTITLED TO EXCHANGE SUCH CERTIFICATE FOR A CERTIFICATE REPRESENTING THE SAME 
NUMBER OF SHARES BUT WITHOUT SUCH LEGEND.

ADMINISTRATION.  ANY DETERMINATION BY THE COMPANY AND ITS COUNSEL IN 
CONNECTION WITH ANY OF THE MATTERS SET FORTH IN THIS SECTION 9 SHALL BE 
CONCLUSIVE AND BINDING ON THE OPTIONEE AND ALL OTHER PERSONS.

ADJUSTMENT OF SHARES.

     ADJUSTMENTS.  IN THE EVENT OF A SUBDIVISION OF THE OUTSTANDING SHARES, A 
DECLARATION OF A DIVIDEND PAYABLE IN SHARES, A DECLARATION OF A DIVIDEND 
PAYABLE IN A FORM OTHER THAN SHARES IN AN AMOUNT THAT HAS A MATERIAL EFFECT 
ON THE PRICE OF SHARES, A COMBINATION OR CONSOLIDATION OF THE OUTSTANDING 
SHARES (BY RECLASSIFICATION OR OTHERWISE) INTO A LESSER NUMBER OF SHARES, A 
RECAPITALIZATION, A SPIN-OFF OR A SIMILAR OCCURRENCE, THE BOARD OF DIRECTORS 
SHALL MAKE SUCH ADJUSTMENTS AS IT, IN ITS SOLE DISCRETION, DEEMS APPROPRIATE 
IN ONE OR MORE OF (a) THE NUMBER OF SHARES COVERED BY THIS OPTION OR (b) THE 
EXERCISE PRICE.  EXCEPT AS PROVIDED IN THIS SECTION 10, THE OPTIONEE SHALL 
HAVE NO RIGHTS BY REASON OF ANY ISSUE BY THE COMPANY OF STOCK OF ANY CLASS OR 
SECURITIES CONVERTIBLE INTO STOCK OF ANY CLASS, ANY SUBDIVISION OR 
CONSOLIDATION OF SHARES OF STOCK OF ANY CLASS, THE PAYMENT OF ANY STOCK 
DIVIDEND OR ANY OTHER INCREASE OR DECREASE IN THE NUMBER OF SHARES OF STOCK 
OF ANY CLASS.

     DISSOLUTION OR LIQUIDATION.  TO THE EXTENT NOT PREVIOUSLY EXERCISED, THIS 
OPTION SHALL TERMINATE IMMEDIATELY PRIOR TO THE DISSOLUTION OR LIQUIDATION OF 
THE COMPANY.

     REORGANIZATIONS.  IN THE EVENT THAT THE COMPANY IS A PARTY TO A MERGER OR 
OTHER REORGANIZATION, THIS OPTION SHALL BE SUBJECT TO THE AGREEMENT OF MERGER 
OR REORGANIZATION.  SUCH AGREEMENT SHALL PROVIDE FOR (a) THE CONTINUATION OF 
THIS OPTION BY THE COMPANY, IF THE COMPANY IS A SURVIVING CORPORATION, (b) 
THE ASSUMPTION OF THIS OPTION BY THE SURVIVING CORPORATION OR ITS PARENT OR 
SUBSIDIARY, (c) THE SUBSTITUTION BY THE SURVIVING CORPORATION OR ITS PARENT 
OR SUBSIDIARY OF ITS OWN OPTION FOR THIS OPTION, (d) FULL EXERCISABILITY AND 
ACCELERATED EXPIRATION OF THIS OPTION OR (e) SETTLEMENT OF THE FULL VALUE OF 
THIS OPTION IN CASH OR CASH EQUIVALENTS FOLLOWED BY CANCELLATION OF THIS 
OPTION.

MISCELLANEOUS PROVISIONS.

RIGHTS AS A STOCKHOLDER.  NEITHER THE OPTIONEE NOR THE OPTIONEE'S 
REPRESENTATIVE SHALL HAVE ANY 

<PAGE>

RIGHTS AS A STOCKHOLDER WITH RESPECT TO ANY SHARES SUBJECT TO THIS OPTION 
UNTIL THE OPTIONEE OR THE OPTIONEE'S REPRESENTATIVE BECOMES ENTITLED TO 
RECEIVE SUCH SHARES BY FILING A NOTICE OF EXERCISE AND PAYING THE PURCHASE 
PRICE PURSUANT TO SECTIONS 4 AND 5.

NOTICE.  ANY NOTICE REQUIRED BY THE TERMS OF THIS AGREEMENT SHALL BE GIVEN IN 
WRITING AND SHALL BE DEEMED EFFECTIVE UPON PERSONAL DELIVERY OR UPON DEPOSIT 
WITH THE UNITED STATES POSTAL SERVICE, BY REGISTERED OR CERTIFIED MAIL, WITH 
POSTAGE AND FEES PREPAID.  NOTICE SHALL BE ADDRESSED TO THE COMPANY AT ITS 
PRINCIPAL EXECUTIVE OFFICE AND TO THE OPTIONEE AT THE ADDRESS THAT HE OR SHE 
MOST RECENTLY PROVIDED TO THE COMPANY.

ENTIRE AGREEMENT.  THE NOTICE OF STOCK OPTION GRANT AND THIS AGREEMENT 
CONSTITUTE THE ENTIRE CONTRACT BETWEEN THE PARTIES HERETO WITH REGARD TO THE 
SUBJECT MATTER HEREOF.  THEY SUPERSEDE ANY OTHER AGREEMENTS, REPRESENTATIONS 
OR UNDERSTANDINGS (WHETHER ORAL OR WRITTEN AND WHETHER EXPRESS OR IMPLIED) 
WHICH RELATE TO THE SUBJECT MATTER HEREOF.

CHOICE OF LAW.  THIS AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED IN 
ACCORDANCE WITH, THE LAWS OF THE STATE OF CALIFORNIA, AS SUCH LAWS ARE 
APPLIED TO CONTRACTS ENTERED INTO AND PERFORMED IN SUCH STATE.

DEFINITIONS.

"AGREEMENT" SHALL MEAN THIS STOCK OPTION AGREEMENT.

"BOARD OF DIRECTORS" SHALL MEAN THE BOARD OF DIRECTORS OF THE COMPANY, AS 
CONSTITUTED FROM TIME TO TIME.

"CHANGE IN CONTROL" SHALL MEAN:

THE CONSUMMATION OF A MERGER OR CONSOLIDATION OF THE COMPANY WITH OR INTO 
ANOTHER ENTITY OR ANY OTHER CORPORATE REORGANIZATION, IF MORE THAN 50% OF THE 
COMBINED VOTING POWER OF THE CONTINUING OR SURVIVING ENTITY'S SECURITIES 
OUTSTANDING IMMEDIATELY AFTER SUCH MERGER, CONSOLIDATION OR OTHER 
REORGANIZATION IS OWNED BY PERSONS WHO WERE NOT STOCKHOLDERS OF THE COMPANY 
IMMEDIATELY PRIOR TO SUCH MERGER, CONSOLIDATION OR OTHER REORGANIZATION;

THE SALE, TRANSFER OR OTHER DISPOSITION OF ALL OR SUBSTANTIALLY ALL OF THE 
COMPANY'S ASSETS;

A CHANGE IN THE COMPOSITION OF THE BOARD OF DIRECTORS, AS A RESULT OF WHICH 
FEWER THAN A MAJORITY OF THE INCUMBENT DIRECTORS ARE DIRECTORS WHO EITHER (A) 
HAD BEEN DIRECTORS OF THE COMPANY ON THE DATE 24 MONTHS PRIOR TO THE DATE OF 
THE EVENT THAT MAY CONSTITUTE A CHANGE IN CONTROL (THE "ORIGINAL DIRECTORS") 
OR (B) WERE ELECTED, OR NOMINATED FOR ELECTION, TO THE BOARD OF DIRECTORS 
WITH THE AFFIRMATIVE VOTES OF AT LEAST A MAJORITY OF THE AGGREGATE OF THE 
ORIGINAL DIRECTORS WHO WERE STILL IN OFFICE AT THE TIME OF THE ELECTION OR 
NOMINATION AND THE DIRECTORS WHOSE ELECTION OR NOMINATION WAS PREVIOUSLY SO 
APPROVED; OR

<PAGE>

ANY TRANSACTION AS A RESULT OF WHICH ANY PERSON IS THE "BENEFICIAL OWNER" (AS 
DEFINED IN RULE 13d-3 UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED), 
DIRECTLY OR INDIRECTLY, OF SECURITIES OF THE COMPANY REPRESENTING AT LEAST 
50% OF THE TOTAL VOTING POWER REPRESENTED BY THE COMPANY'S THEN OUTSTANDING 
VOTING SECURITIES.  FOR PURPOSES OF THIS PARAGRAPH (iv), THE TERM "PERSON" 
SHALL HAVE THE SAME MEANING AS WHEN USED IN SECTIONS 13(d) AND 14(d) OF SUCH 
ACT BUT SHALL EXCLUDE (A) A TRUSTEE OR OTHER FIDUCIARY HOLDING SECURITIES 
UNDER AN EMPLOYEE BENEFIT PLAN OF THE COMPANY OR OF A PARENT OR SUBSIDIARY 
AND (B) A CORPORATION OWNED DIRECTLY OR INDIRECTLY BY THE STOCKHOLDERS OF THE 
COMPANY IN SUBSTANTIALLY THE SAME PROPORTIONS AS THEIR OWNERSHIP OF THE 
COMMON STOCK OF THE COMPANY.

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

<PAGE>

"COMPANY" SHALL MEAN FORTE SOFTWARE, INC., A DELAWARE CORPORATION.

"CONSULTANT" SHALL MEAN A PERSON WHO PERFORMS BONA FIDE SERVICES FOR THE 
COMPANY, A PARENT OR A SUBSIDIARY AS A CONSULTANT OR ADVISOR, EXCLUDING 
EMPLOYEES AND OUTSIDE DIRECTORS.

"DATE OF GRANT" SHALL MEAN THE DATE SPECIFIED IN THE NOTICE OF STOCK OPTION 
GRANT, WHICH SHALL BE THE DATE ON WHICH THE BOARD OF DIRECTORS RESOLVED TO 
GRANT THIS OPTION.

"DISABILITY" SHALL MEAN THAT THE OPTIONEE IS UNABLE TO ENGAGE IN ANY 
SUBSTANTIAL GAINFUL ACTIVITY BY REASON OF ANY MEDICALLY DETERMINABLE PHYSICAL 
OR MENTAL IMPAIRMENT WHICH CAN BE EXPECTED TO RESULT IN DEATH OR WHICH HAS 
LASTED, OR CAN BE EXPECTED TO LAST, FOR A CONTINUOUS PERIOD OF NOT LESS THAN 
12 MONTHS.

"EMPLOYEE" SHALL MEAN ANY INDIVIDUAL WHO IS A COMMON-LAW EMPLOYEE OF THE 
COMPANY, A PARENT OR A SUBSIDIARY.

"EXERCISE PRICE" SHALL MEAN THE AMOUNT FOR WHICH ONE SHARE MAY BE PURCHASED 
UPON EXERCISE OF THIS OPTION, AS SPECIFIED IN THE NOTICE OF STOCK OPTION 
GRANT.

"FAIR MARKET VALUE" SHALL MEAN THE FAIR MARKET VALUE OF A SHARE, AS 
DETERMINED BY THE BOARD OF DIRECTORS IN GOOD FAITH.  SUCH DETERMINATION SHALL 
BE CONCLUSIVE AND BINDING ON ALL PERSONS.

"NONSTATUTORY OPTION" SHALL MEAN A STOCK OPTION NOT DESCRIBED IN SECTIONS 
422(b) OR 423(b) OF THE INTERNAL REVENUE CODE OF 1986, AS AMENDED.

"NOTICE OF STOCK OPTION GRANT" SHALL MEAN THE DOCUMENT SO ENTITLED TO WHICH 
THIS AGREEMENT IS ATTACHED.

"OPTIONEE" SHALL MEAN THE INDIVIDUAL NAMED IN THE NOTICE OF STOCK OPTION 
GRANT.

"OUTSIDE DIRECTOR" SHALL MEAN A MEMBER OF THE BOARD OF DIRECTORS WHO IS NOT 
AN EMPLOYEE.

"PARENT" SHALL MEAN ANY CORPORATION (OTHER THAN THE COMPANY) IN AN UNBROKEN 
CHAIN OF CORPORATIONS ENDING WITH THE COMPANY, IF EACH OF THE CORPORATIONS 
OTHER THAN THE COMPANY OWNS STOCK POSSESSING 50% OR MORE OF THE TOTAL 
COMBINED VOTING POWER OF ALL CLASSES OF STOCK IN ONE OF THE OTHER 
CORPORATIONS IN SUCH CHAIN.

"PURCHASE PRICE" SHALL MEAN THE EXERCISE PRICE MULTIPLIED BY THE NUMBER OF 
SHARES WITH RESPECT TO WHICH THIS OPTION IS BEING EXERCISED.

"SECURITIES ACT" SHALL MEAN THE SECURITIES ACT OF 1933, AS AMENDED.

"SERVICE" SHALL MEAN SERVICE AS AN EMPLOYEE, OUTSIDE DIRECTOR OR CONSULTANT.

"SHARE" SHALL MEAN ONE SHARE OF STOCK, AS ADJUSTED IN ACCORDANCE WITH SECTION 
10 (IF 

<PAGE>

APPLICABLE). 

"STOCK" SHALL MEAN THE COMMON STOCK OF THE COMPANY.

         A. "SUBSIDIARY" SHALL MEAN ANY CORPORATION (OTHER THAN THE COMPANY) IN 
            AN UNBROKEN CHAIN OF CORPORATIONS BEGINNING WITH THE COMPANY, IF 
            EACH OF THE CORPORATIONS OTHER THAN THE LAST CORPORATION IN THE
            UNBROKEN CHAIN OWNS STOCK POSSESSING 50% OR MORE OF THE TOTAL 
            COMBINED VOTING POWER OF ALL CLASSES OF STOCK IN ONE OF THE OTHER
            CORPORATIONS IN SUCH CHAIN.