PEGASYSTEMS INC.
                        1996 EMPLOYEE STOCK PURCHASE PLAN


 l.     PURPOSE. The purpose of this Employee Stock Purchase Plan (the "Plan")
        is to provide employees of Pegasystems Inc., a Massachusetts corporation
        (the "Company"), and its subsidiaries, who wish to become stockholders
        of the Company an opportunity to purchase shares of the Common Stock,
        $.01 par value per share, of the Company (the "Shares"). The Plan is
        intended to qualify as an "employee stock purchase plan" within the
        meaning of Section 423 of the Internal Revenue Code of 1986, as amended
        (the "Code").

 2.     ELIGIBLE EMPLOYEES. Subject to provisions of Sections 7, 8 and 9 below,
        any individual who is in the full-time employment (as defined below) of
        the Company, or any of its subsidiaries (as defined in Section 424(f) of
        the Code) the employees of which are designated by the Board of
        Directors of the Company (the "Board") as eligible to participate in the
        Plan, is eligible to participate in any Offering of Shares (as defined
        in Section 3 below) made by the Company hereunder. Full-time employment
        shall include all employees whose customary employment is:

        (a)    in excess of 20 hours per week; and

        (b)    more than five months in the relevant calendar year.

 3.     OFFERING DATES. From time to time the Company, by action of the Board,
        will grant rights to purchase Shares to employees eligible to
        participate in the Plan pursuant to one or more offerings (each of which
        is an "Offering") on a date or series of dates (each of which is an
        "Offering Date") designated for this purpose by the Board.

 4.     PRICES.  The Price per share for each grant of rights hereunder shall be
        the lesser of:

        (a)    eighty-five percent (85%) of the fair market value of a Share on
               the Offering Date on which such right was granted; or

        (b)    eighty-five percent (85%) of the fair market value of a Share on
               the date such right is exercised.

        At its discretion, the Board of Directors may determine a higher price
        for a grant of rights.

        For purposes of this Plan, the term "fair market value" on any date
        means (i) the average (on that date) of the high and low prices of the
        Company's Common Stock on the principal national securities exchange on
        which the Common Stock is traded, if the Common Stock is then traded on
        a national securities exchange; or (ii) the last reported sale price (on
        that date) of the Common Stock on the Nasdaq National Market System, if
        the Common Stock is not then traded on a national securities exchange;
        or (iii) the average of the closing bid and asked prices last quoted (on
        that date) by an established quotation service for over-the-counter
        securities, if the Common Sock is not reported on the Nasdaq National
        Market




        System or on a national securities exchange. If the Company's
        Common Stock is not publicly traded at the time a right is granted under
        this Plan, "fair market value" shall mean the fair market value of the
        Common Stock as determined by the Board 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.

 5.     EXERCISE OF RIGHTS AND METHOD OF PAYMENT.

        (a)    Rights granted under the Plan will be exercisable periodically on
               specified dates as determined by the Board.

        (b)    The method of payment for Shares purchased upon exercise of
               rights granted hereunder shall be through regular payroll
               deductions or by lump sum cash payment, or both, as determined by
               the Board. No interest shall be paid upon payroll deductions
               unless specifically provided for by the Board.

        (c)    Any payments received by the Company from a participating
               employee and not utilized for the purchase of Shares upon
               exercise of a right granted hereunder shall be promptly returned
               to such employee by the Company after termination of the right to
               which the payment relates.

 6.     TERM OF RIGHTS. Rights granted on any Offering Date shall be exercisable
        upon the expiration of such period ("Offering Period") as shall be
        determined by the Board when it authorizes the Offering, provided that
        such Offering Period shall in no event be longer than twenty-seven (27)
        months.


 7.     SHARES SUBJECT TO THE PLAN. No more than 500,000 (after giving effect to
        a 3-for-1 stock split in the form of a stock dividend to be effective on
        July 10, 1996) Shares may be sold pursuant to rights granted under the
        Plan; provided, however, that appropriate adjustment shall be made in
        such number, in the number of Shares covered by outstanding rights
        granted hereunder, in the exercise price of the rights and in the
        maximum number of Shares which an employee may purchase (pursuant to
        Section 9 below) to give effect to any mergers, consolidations,
        reorganizations, recapitalizations, stock splits, stock dividends or
        other relevant changes in the capitalization of the Company occurring
        after the effective date of the Plan, provided that no fractional Shares
        shall be subject to a right and each right shall be adjusted downward to
        the nearest full Share. Any agreement of merger or consolidation will
        include provisions for protection of the then existing rights of
        participating employees under the Plan. Either authorized and unissued
        Shares or issued Shares heretofore or hereafter reacquired by the
        Company may be made subject to rights under the Plan. If for any reason
        any right under the Plan terminates in whole or in part, Shares subject
        to such terminated right may again be subjected to a right under the
        Plan.


 8.     LIMITATIONS ON GRANTS.

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        (a)    No employee shall be granted a right hereunder if such employee,
               immediately after the right is granted, would own stock or rights
               to purchase stock possessing five percent (5%) or more of the
               total combined voting power or value of all classes of stock of
               the Company, or of any subsidiary, computed in accordance with
               Sections 423(b)(3) and 424(d) of the Code.

        (b)    No employee shall be granted a right which permits his right to
               purchase shares under all employee stock purchase plans of the
               Company and its subsidiaries to accrue at a rate which exceeds
               twenty-five thousand dollars ($25,000) (or such other maximum as
               may be prescribed from time to time by the Code) of the fair
               market value of such Shares (determined at the time such right is
               granted) for each calendar year in which such right is
               outstanding at any time in accordance with the provisions of
               Section 423(b)(8) of the Code.

        (c)    No right granted to any participating employee under a single
               Offering shall cover more shares than may be purchased at an
               exercise price equal to 10% of the base salary payable to the
               employee during the Offering not taking into consideration any
               changes in the employee's rate of compensation after the date the
               employee elects to participate in the Offering, or such other
               percentage as determined by the Board from time to time. This
               provision shall be construed to meet the requirements set forth
               in Section 423(b)(5) of the Code.

 9.     LIMIT ON PARTICIPATION. Participation in an Offering shall be limited to
        eligible employees who elect to participate in such Offering in the
        manner, and within the time limitation, established by the Board when it
        authorizes the offering.

 10.    CANCELLATION OF ELECTION TO PARTICIPATE. An employee who has elected to
        participate in an Offering may, unless the employee has waived this
        cancellation right at the time of such election in a manner established
        by the Board, cancel such election as to all (but not part) of the
        rights granted under such Offering by giving written notice of such
        cancellation to the Company before the expiration of the Offering
        Period. Any amounts paid by the employee for the Shares or withheld for
        the purchase of Shares from the employee's compensation through payroll
        deductions shall be paid to the employee, without interest, upon such
        cancellation.

11.     TERMINATION OF EMPLOYMENT. Upon termination of employment for any
        reason, including the death of the employee, before the date on which
        any rights granted under the Plan are exercisable, all such rights shall
        immediately terminate and amounts paid by the employee for the Shares or
        withheld for the purchase of Shares from the employee's compensation
        through payroll deductions shall be paid to the employee or to the
        employee's estate, without interest.

12.     EMPLOYEE'S RIGHTS AS STOCKHOLDER. No participating employee shall have
        any rights as a stockholder in the Shares covered by a right granted
        hereunder until such right

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        has been exercised, full payment has been made for the corresponding
        Shares and a certificate for the Shares is actually issued.

 13.    RIGHTS NOT TRANSFERABLE. Rights under the Plan are not assignable or
        transferable by a participating employee and are exercisable only by the
        employee.

 14.    LIMITS ON SALE OF STOCK PURCHASED UNDER THE PLAN. The Plan is intended
        to provide shares of Common Stock for investment and not for resale. The
        Company does not, however, intend to restrict or influence any employee
        in the conduct of his or her own affairs. An employee may, therefore,
        sell stock purchased under the Plan at any time the employee chooses,
        subject to compliance with any applicable federal or state securities
        laws; provided, however, that because of certain federal tax
        requirements, each employee agrees by entering the Plan, promptly to
        give the Company notice of any such stock disposed of within two years
        after the date of grant or within one year of the date of exercise of
        the applicable right, such notice to set forth the number of such shares
        disposed of. THE EMPLOYEE ASSUMES THE RISK OF ANY MARKET FLUCTUATIONS IN
        THE PRICE OF THE STOCK.

 15.    AMENDMENTS TO OR DISCONTINUANCE OF THE PLAN. The Board may at any time
        terminate or amend the Plan without notice and without further action on
        the part of stockholders of the Company, provided:

        (a)    that no such termination or amendment shall adversely affect the
               then existing rights of any participating employee; and

        (b)    that any such amendment which:

                 (i)  increases  the  number  of  Shares  subject  to the Plan 
                      (subject  to the provisions of Section 7);

                (ii)  changes the class of persons eligible to participate under
                      the Plan; or

               (iii)  materially increases the benefits accruing to participants
                      under the Plan

        shall be subject to approval of the stockholders of the Company.

 16.    EFFECTIVE DATE AND APPROVALS. The Plan was adopted by the Board on May
        13, 1996 to become effective as of said date. The Company's obligation
        to offer, sell and deliver its Shares under the Plan is subject to the
        approval of its stockholders not later than May 13, 1997 and of any
        governmental authority required in connection with the authorized
        issuance or sale of such Shares and is further subject to the Company
        receiving the opinion of its counsel that all applicable securities laws
        have been complied with.

 17.    TERM OF PLAN. No rights shall be granted under the Plan after May 13,
        2006.

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 18.    ADMINISTRATION OF THE PLAN. The Board or any committee or persons to
        whom it delegates its authority (the "Administrator") shall administer,
        interpret and apply all provisions of the Plan. The Administrator may
        waive such provisions of the Plan as it deems necessary to meet special
        circumstances not anticipated or covered expressly by the Plan. Nothing
        contained in this Section shall be deemed to authorize the Administrator
        to alter or administer the provisions of the Plan in a manner
        inconsistent with the provisions of Section 423 of the Code. No member
        of the Administrator shall be liable for any action or determination
        made in good faith with respect to the Plan or any right granted under
        it.

        Date approved by the Board
        of Directors of the Company:        May 13, 1996


        Date approved by the
        Stockholders of the Company:        June 26, 1996


ds1-256712.1

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