EXHIBIT 10.11

                       PARAMETRIC TECHNOLOGY CORPORATION
                       1991 EMPLOYEE STOCK PURCHASE PLAN

                   (as adopted by the Board of Directors on
                November 21, 1990, approved by the stockholders
           on February 27, 1991, and amended to reflect one-for-two,
                          one-for-one and one-for-one
                  stock dividends effective on June 27, 1991,
            February 25, 1992 and February 25, 1993, respectively,
          amended by the Board of Directors on November 17, 1994, and
               approved by the stockholders on February 9, 1995


1.     Purposes.
       --------

       The 1991 Employee Stock Purchase Plan of Parametric Technology
Corporation (the "Plan") is intended to provide a method whereby employees of
Parametric Technology Corporation and participating subsidiaries (hereinafter
collectively referred to, unless the context otherwise requires, as the
"Company") will have an opportunity to acquire a proprietary interest in the
Company through the purchase of shares of the common stock, $.01 par value per
share, of the Company ("Common Stock"). It is the intention of the Company to
have the Plan qualify as an "employee stock purchase plan" under Section 423 of
the Internal Revenue Code of 1986, as amended (the "Code"). The provisions of
the Plan shall, accordingly, be construed so as to extend and limit
participation in a manner consistent with the requirements of Section 423 of the
Code. However, unless specified in the Code, the fact that an employee is not a
resident of the United States and therefore may not receive the tax benefits
under the Code will not bar such employee from participation in the Plan.

2.     Definitions.
       ----------- 

       (a)     "Coordinator" means the officer of the Company or other person
charged with day-to-day supervision of the Plan as appointed from time to time
by the Board of Directors of the Company (the "Board of Directors"). The Manager
of Human Resources of the Company shall be the initial Coordinator. Notice of
any change in such Coordinator shall be given to all employees eligible under
the Plan.

       (b)     "Base Pay" means regular straight-time earnings (as the same may
be adjusted from time to time), excluding payments for commissions, overtime,
shift differentials, incentive compensation, bonuses and other special payments.
Disability insurance payments shall not be included in Base Pay for purposes of
the Plan

       (c)     "employee" means any person who is customarily employed for 20 or
more hours per week and more than five months in a calendar year by the Company
or by a participating subsidiary.

 
       (d)     "Offering Commencement Date" means the applicable date on which
an Offering under the Plan commences pursuant to Paragraph 4.

       (e)     "Offering Termination Date" means the applicable date on which an
Offering under the Plan terminates pursuant to Paragraph 4.

       (f)     "Participating subsidiary" means any present or future
corporation which (i) is a "subsidiary corporation" as that term is defined in
Section 425 of the Code and (ii) is designated as a participant in the Plan by
the Board of Directors or the Compensation Committee thereof.

3.Eligibility.
  ----------- 

       (a)     Any employee who has completed at least 90 days of employment
with the Company and who shall be employed by the Company on the applicable
Offering Commencement Date shall be eligible to participate in such Offering
under the Plan.

       (b.)    Any provision of the Plan to the contrary notwithstanding, no
employee shall be granted an option under the Plan (an "Option") if, immediately
after the grant, such employee would own stock, and/or hold outstanding options
to purchase stock, possessing 5% or more of the total combined voting power or
value of all classes of stock of the Company or of any subsidiary (for purposes
of this subparagraph the rules of Section 425(d) of the Code shall apply in
determining stock ownership of any employee and the term subsidiary shall be as
defined in Section 425(f) of the Code).

       (c)     Any provision of the Plan or any other employee stock purchase
plan of the Company to the contrary notwithstanding, no employee shall have the
right to purchase Common Stock under the Plan to the extent that the fair market
value (determined at the Offering Commencement Date in accordance with
subparagraph 7(b)(1)) of the shares of Common Stock (or other stock of the
Company and any subsidiary) which such employee would otherwise become entitled
to purchase during the calendar year under the Plan and under all other employee
stock purchase plans of the Company exceeds $25,000.

4.     Offering Dates.
       -------------- 

       The Plan will be implemented by seventeen (17) six-month offerings, one
beginning every six months commencing April 1, 1991 until and including April 1,
1999 (referred to herein collectively as "Offerings" and individually as an
"Offering"), as follows:

       (a)     Offering I shall commence on April 1, 1991, and terminate on
September 30, 1991.

       (b)     Offering II shall commence on October 1, 1991, and terminate on
March 31, 1992.

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       (c)     Offering III shall commence on April 1, 1992, and terminate on
September 30, 1992.

       (d)     Offering IV shall commence on October 1, 1992, and terminate on
March 31, 1993.

       (e)     Offering V shall commence on April 1, 1993, and terminate on
September 30, 1993.

       (f)     Offering VI shall commence on October 1, 1993, and terminate on
March 31, 1994.

       (g)     Offering VII shall commence on April 1, 1994, and terminate on
September 30, 1994.

       (h)     Offering VIII shall commence on September 30, 1994, and terminate
on March 31, 1995.

       (i)     Offering IX shall commence on April 3, 1995, and terminate on
September 29, 1995.

       (j)     Offering X shall commence on October 2, 1995, and terminate on
March 29, 1996.

       (k)     Offering XI shall commence on April 1, 1996, and terminate on
September 30, 1996.

       (l)     Offering XII shall commence on October 1, 1996, and terminate on
March 31, 1997.

       (m)     Offering XIII shall commence on April 1, 1997, and terminate on
September 30, 1997.

       (n)     Offering XIV shall commence on October 1, 1997, and terminate on
March 31, 1998.

       (o)     Offering XV shall commence on April 1, 1998, and terminate on
September 30, 1998.

       (p)     Offering XVI shall commence on October 1, 1998, and terminate on
March 31, 1999.

                                      -3-

 
       (q)     Offering XVII shall commence on April 1, 1999, and terminate on
September 30, 1999.

Participation in any one or more of the seventeen Offerings under the Plan shall
neither limit, nor require, participation in any other Offering.

5.     Participation.
       ------------- 

       (a)     An eligible employee may become a participant in the Plan by
completing an authorization for a payroll deduction ("Authorization") on the
form provided by the Company and filing the Authorization with the Company at
least 15 days and no more than 30 days prior to the applicable Offering
Commencement Date immediately preceding such eligible employee's initial
participation in the Plan.  Such Authorization shall remain in effect until the
participant files a new Authorization with the Company terminating his or her
participation or otherwise amending the most recent Authorization by filing a
new Authorization with the Company at least 15 days but no more than 30 days
prior to the next Offering Commencement Date.

       (b)     Payroll deductions for a participant shall commence with the
first payday on or after the applicable Offering Commencement Date of the
Offering for which such participant's Authorization is filed and shall end with
the final payday on or before the Offering Termination Date of such Offering,
unless sooner terminated pursuant to Paragraph 10.

6.     Payroll Deductions.
       ------------------ 

       (a)     At the time a participant files his or her Authorization, the
participant shall elect to have deductions made for his or her Base Pay on each
payday during the time he or she is a participant in an Offering at the rate of
1, 2, 3, 4, 5, 6, 7, 8, 9 or 10% of his or her Base Pay in effect on the
applicable Offering Commencement Date.  Notwithstanding the foregoing, the
participant's participation in any one or combination of Offerings under the
Plan, shall not exceed, in any fiscal year, an aggregate of the lesser of (i)
$10,000 or (ii) 10% of the participant's Base Pay.

       (b)     All payroll deductions made for a participant shall be credited
to his or her account maintained by the Company under the Plan. A participant
may not make any separate cash payment into such account.

       (c)     Except as provided in Paragraph 10, a participant may not make
any changes to his or her participation during an Offering and, specifically, a
participant may not during an Offering alter the percentage of his or her Base
Pay deducted and credited to his or her account under the Plan. However, if the
Base Pay of the participating employee increases or decreases during the period
of an Offering, the dollar amount of his or her payroll deductions will increase
or decrease accordingly.

                                      -4-

 
7.     Granting of Option.
       ------------------ 

       (a)     Subject to Paragraph 3, for each of the Offerings, a
participating employee shall be deemed to have been granted, on the applicable
Offering Commencement Date, an Option to purchase, on the applicable Offering
Termination Date, a maximum number of shares of Common Stock equal to an amount
determined by (i) multiplying the employee's annualized base pay as of the
Offering Commencement Date by the percentage of such base pay which he or she
has elected to have withheld (but not in any case in excess of 10%); (ii)
dividing such product by 85% of the fair market value of a share of the Common
Stock on the applicable Offering Commencement Date; and (iii) multiplying such
quotient by 1.25. For all purposes of the Plan, the fair market value of the
Common Stock shall be determined as provided in clause (i) of subparagraph (b)
below. For purposes of this paragraph (a), "Annualized Base Pay" shall mean Base
Pay on an annualized basis, determined as follows: (i) in the case of a full-
time employee normally paid on an hourly rate, by multiplying his or her normal
hourly rate by 2080, (ii) in the case of a part-time employee normally paid on
an hourly rate, by multiplying his or her normal hourly rate by the product of
52 times the number of hours in his or her normal work week, (iii) in the case
of an employee normally paid at a bi-weekly rate, by multiplying his or her
normal bi-weekly rate by 26, (iv) in the case of an employee normally paid at a
weekly rate, by multiplying his or her normal weekly rate by 52, and (v) in the
case of an employee normally paid at a monthly rate, by multiplying his or her
normal monthly rate by 12.

       (b)     The purchase price per share of Common Stock purchased during
each Offering (the "Option Exercise Price") shall be the lower of:

               (i)    85% of the last sale price of the Common Stock on the
               NASDAQ National Market System or, if the Common Stock is listed
               on a national securities exchange, 85% of the closing price of
               the Common Stock on such exchange, on the applicable Offering
               Commencement Date (or on the next regular business day on which
               shares of Common Stock shall be traded if no shares of Common
               Stock shall have been traded on such Offering Commencement Date),
               as reported in The Wall Street Journal; or
                              ----------------------- 
          

               (ii)   85% of the last sale price of Common Stock on the NASDAQ
               National Market System or, if the Common Stock is listed on a
               national securities exchange, 85% of the closing price of the
               Common Stock on such exchange, on the applicable Offering
               Termination Date (or on the next regular business day on which
               shares of Common Stock shall be traded if no shares of Common
               Stock shall have been traded on such Offering Termination Date),
               as reported in The Wall Street Journal.
                              ----------------------- 

8.     Exercise of Option.
       ------------------ 

                                      -5-

 
       With respect to each Offering during the term of the Plan:

       (a)     Unless a participant has given written notice of withdrawal to
the Company as provided in Paragraph 10, his or her Option will be deemed to
have been exercised automatically on the Offering Termination Date applicable to
such Offering, for the purchase of the number of full shares of Common Stock
which the accumulated payroll deductions (without interest) in his or her
account maintained by the Company under the Plan at that time will purchase at
the applicable Option Exercise Price (provided that (i) such number of shares
may be reduced pursuant to Paragraph 12 in the event the Offering is
oversubscribed and (ii) such number of shares may not exceed the number of
shares covered by the Option granted to the participant pursuant to Paragraph
7(a)), and any excess in his or her account at that time will be returned to him
or her without interest promptly following the termination of the Offering.

       (b)     Fractional shares will not be issued under the Plan and any
accumulated payroll deductions which would have been used to purchase fractional
shares shall be returned (without interest) to a participant promptly following
the termination of the Offering.

9.     Delivery.
       -------- 

       As promptly as practicable after the Offering Termination Date of each
Offering, the Company will deliver to each participant a certificate
representing the shares of Common Stock purchased upon the exercise of such
participant's Option.

10.    Withdrawal.
       ---------- 

       (a)     A participant may elect to withdraw all, but not less than all,
payroll deductions credited to his or her account with the Company under any
Offering at any time prior to the applicable Offering Termination Date by giving
written notice of withdrawal to the Coordinator.  All of the participant's
payroll deductions credited to his or her account will be paid to the
participant (without interest) promptly after receipt of such notice of
withdrawal and no further payroll deductions will be made from his or her pay
during such Offering.  The Company may, at its option, treat any attempt by a
participant to borrow on the security of accumulated payroll deductions as an
election, under this Paragraph, to withdraw such deductions.

       (b)     A participant's withdrawal from any Offering will not have any
effect upon his or her eligibility to participate in any succeeding Offering or
in any similar plan which may hereafter be adopted by the Company; provided,
                                                                   --------
however, that an officer (as defined in Section 16, and the rules promulgated
- -------
thereunder ("Section 16"), of the Securities Exchange Act of 1934, as amended
(the "Exchange Act")) or director of the Company who terminates his or her
participation in the Plan prior to the end of any Offering may not participate
in the next Offering under the Plan.

                                      -6-

 
       (c)     Upon termination of the participant's employment for any reason,
including retirement but excluding death or disability (as defined in Section
22(e)(3) of the Code) while in the employ of the Company, such participant will
be deemed to have withdrawn from participation in the pending Offering, and the
payroll deductions credited to his or her account will be returned to the
participant (without interest), or, in the case of his or her death subsequent
to the termination of employment, to the person or persons entitled thereto
under Paragraph 14.

       (d)     Upon termination of the participant's employment because of
disability or death, the participant or his or her beneficiary (as defined in
Paragraph 14) shall have the right to elect, by written notice given to the
Coordinator prior to the expiration of the period of 30 days commencing with the
date of the disability or death of the participant, either

               (i)    to withdraw all of the payroll deductions credited to the
               participant's account under the Plan (without interest); or

               (ii)   to exercise the participant's Option on the applicable
               Offering Termination Date for the purchase of the number of full
               shares of Common Stock which the accumulated payroll deductions
               (without interest) in the participant's account at the date of
               the participant's disability or death will purchase at the
               applicable Option Exercise Price, and to receive any excess money
               in such account (without interest).

       If no such written notice of election is received by the Coordinator, the
participant or beneficiary shall automatically be deemed to have elected to
withdraw the payroll deductions credited to the participant's account at the
date of the participant's disability or death and the same will be paid promptly
following such 30-day period to the participant or said beneficiary without
interest.

11.    Interest.
       -------- 

       No interest will be paid or allowed on any money paid into the Plan or
credited to the account of any participant employee.

12.    Stock.
       ----- 

       (a)     The maximum number of shares of Common Stock which shall be made
available for sale under the Plan during the Offerings is 1,000,000 shares,
subject to adjustment upon changes in capitalization of the Company as provided
in Paragraph 17 .

       (b)     Subject to adjustment upon changes in capitalization of the
Company as provided in Paragraph 17 and subject to adjustment for carry-over
shares from previous Offerings as set forth below, the maximum number of shares
available for sale under the Plan during Offerings I through VIII is as follows:

                                      -7-

 
               Offering I     -    90,000
               Offering II    -    90,000
               Offering III   -    78,000
               Offering IV    -    78,000
               Offering V     -    72,000
               Offering VI    -    72,000
               Offering VII   -    60,000
               Offering VIII  -    60,000


If the total number of shares for which Options are exercised on any Offering
Termination Date in accordance with Paragraph 8 exceeds the maximum number of
shares available for such Offering, the Company shall make a pro rata allocation
(based on the number of shares subject to the Option held by each participant)
of the shares available for delivery and distribution in as nearly a uniform
manner as shall be practicable and as it shall determine to be equitable, and
the balance of payroll deductions credited to the account of each participant
under the Plan shall be returned to him or her (without interest) as promptly as
practicable.  If less than the maximum number of shares available in an Offering
(including any carryover shares from a previous Offering) are purchased during
an Offering, the number not purchased shall be carried over to and made
available in the next subsequent Offering.

       (c)     Subject only to the limit set forth in Paragraph 12(a) above,
there shall be no maximum number of shares available for sale during any of
Offerings IX through XVII. If less than the maximum number of shares available
in Offerings I through VII are purchased during such Offerings, the number not
purchased shall be carried over to and made available for Offerings IX through
XVII. If the total number of shares for which Options are exercised on any
Offering Termination Date in accordance with Paragraph 8 (together with all
prior exercises under the Plan during such Offering) exceeds the maximum number
of shares available under the Plan as set forth in Paragraph 12(a) above, the
Company shall make a pro rata allocation (based on the number of shares subject
to the Option held by each participant) of the shares available for delivery and
distribution in as nearly a uniform manner as shall be practicable and as it
shall determine to be equitable, and the balance of payroll deductions credited
to the account of each participant under the Plan shall be returned to him or
her (without interest) as promptly as practicable. In such event, no further
Offerings shall be commenced under the Plan unless and until the Plan is amended
to increase the number of shares set forth in Paragraph 12(a) above.

       (d)     The participant will have no interest in the Common Stock covered
by his or her Option until such Option has been exercised.

       (e)     Certificates for Common Stock to be delivered to a participant
under the Plan will be registered in the name of the participant, or, if the
participant so directs by written

                                      -8-

 
notice to the Company prior to the Offering Termination Date applicable thereto,
in the names of the participant and one such other person as may be designated
by the participant, as joint tenants with rights of survivorship, to the extent
permitted by applicable law.

13.    Administration.
       -------------- 

       The Plan shall be administered by the Compensation Committee of the Board
of Directors of the Company (the "Committee"). The Coordinator shall, for
matters  involving the Plan, be an ex officio member of that Committee.  The
                                   ----------                               
interpretation and construction of any provision of the Plan and the adoption of
rules and regulations for administering the Plan shall be made by the Committee,
subject, however, at all times to the final jurisdiction which shall rest in the
Board of Directors.  Determinations made by the Committee and approved by the
Board of Directors with respect to any matter or provision contained in the Plan
shall be final, conclusive and binding upon the Company and upon all
participants, their heirs or legal representatives.  Any rule or regulation
adopted by the Committee shall remain in full force and effect unless and until
altered, amended, or repealed by the Committee or the Board of Directors.  The
Company shall indemnify Committee members, to the fullest extent permitted by
applicable law, for any expenses incurred in defending a civil or criminal
action or proceeding, arising out of such member's actions with respect to
administration of the Plan, in advance of the final disposition of such action
or proceeding, upon receipt of an undertaking by the person indemnified to repay
such payment if such member shall be adjudicated not to have acted in good faith
in the reasonable belief that such member's action was in the best interest of
the Company.

                                      -9-

 
14.    Designation of Beneficiary
       --------------------------

       A participant may file a written designation of a beneficiary who is
to receive any shares of Common Stock and/or cash in the event of the death of
the participant.  Such designation shall be effective as to all future
distributions of cash and securities with respect to the participant's account
under the Plan.  Such designation of beneficiary may be changed by the
participant at any time by written notice to the Coordinator.  Within 30 days
after the participant's death, the beneficiary may, as provided in Paragraph
10(d), elect to exercise the participant's Option when it becomes exercisable on
the Offering Termination Date of the then current Offering.  Upon the death of a
participant and upon receipt by the Company of proof of the identity and
existence at the participant's death of a beneficiary validly designated by the
participant under the Plan, and notice of election of the beneficiary to
exercise the participant's Option, the Company shall deliver such stock and/or
cash to such beneficiary.  In the event of the death of a participant and in the
absence of a beneficiary validly designated under the Plan who is living at the
time of such participant's death, the Company shall deliver such cash to the
executor or administrator of the estate of the participant, or if no such
executor or administrator has been appointed (to the knowledge of the Company),
the Company, in its discretion, may deliver such cash to the spouse or to any
one or dependents of the participant as the Company may determine.  No
beneficiary shall prior to the death of the participant by whom he has been
designated acquire any interest in the stock or cash credited to the
participant's account maintained by the Company under the Plan.

15.    Transferability.
       --------------- 

       Neither payroll deductions credited to a participant's account nor any
rights with regard to the exercise of an Option or to receive Common Stock under
the Plan may be assigned, transferred, pledged, or otherwise disposed of in any
way by the participant otherwise than by will or the laws of descent and
distribution or, in the case of an officer (as defined in Section 16 of the
Exchange Act) or director of the Company, by such other means as may be
permitted by Rule 16b-3 (or any successor provision) under the Exchange Act.
Any such attempted assignment, transfer, pledge, or other disposition shall be
without effect, except that the Company may treat such act as an election to
withdraw funds in accordance with Paragraph 10.  Notwithstanding anything to the
contrary contained herein, shares of Common Stock acquired under the Plan by an
officer (as defined in Section 16 the Exchange Act) or director of the Company
may not be assigned, transferred, pledged, or otherwise disposed of for at least
six months following the Offering Termination Date of the Offering in which such
shares of Common Stock are acquired.

16.    Use of Funds.
       ------------ 

       All payroll deductions received or held by the Company under this Plan
may be used by the Company for any corporate purpose and the Company shall not
be obligated to segregate such payroll deductions.

                                      -10-

 
17.    Effect of Changes of Common Stock.
       --------------------------------- 

       In the event of any changes in outstanding shares of Common Stock by
reason of stock dividends, subdivisions, combinations and exchanges of shares,
recapitalizations, and the like, the aggregate number and class of shares
available under the Plan and the Option Exercise Price per share shall be
appropriately adjusted by the Board of Directors of the Company, whose
determination shall be conclusive.  Any such adjustments may provide for the
elimination of any fractional shares which would otherwise become subject to any
Options.

18.    Amendment or Termination.
       ------------------------ 

       The Committee or the Board of Directors may at any time terminate or
amend the Plan, provided that no amendment may be made to the Plan without
approval of the stockholders of the Company if such approval is required in
order to comply with Rule 16b-3 under the Exchange Act and other applicable
securities and tax laws.  If the Board of Directors elects at any time to
terminate the Plan, the payroll deductions credited to each participant's
account will be returned to the participant (without interest) as soon as
practicable after such termination.

19.    Notices.
       ------- 

       All notices or other communications by a participant to the Company
under or in connection with the Plan shall be deemed to have been duly given
when received by the Coordinator.

20.    Merger or Consolidation.
       ----------------------- 

       If the Company shall at any time merge or consolidate with another
corporation and the Company is the surviving entity, the holder of each Option
then outstanding will thereafter be entitled to receive at the next Offering
Termination Date upon the automatic exercise of such Option under Paragraph 8(a)
(unless previously withdrawn pursuant to Paragraph 10) for each share as to
which such Option shall be exercised the securities or property which a holder
of one share of the Common Stock was entitled to upon and at the time of such
merger or consolidation, and the Board of Directors shall take such steps in
connection with such merger or consolidation as the Board of Directors shall
deem necessary to ensure that the provisions of Paragraph 17 shall thereafter be
applicable, as nearly as reasonably may be, to such securities or property.  In
the event of a merger or consolidation in which the Company is not the surviving
entity, or of a sale of substantially all of the assets of the Company, the Plan
shall terminate, and all payroll deductions credited to participants' accounts
shall be returned to them (without interest) provided, however, that the Board
of Directors may, in the event of such merger or sale, accelerate the Offering
Termination Date of the Offering then in effect and permit participants to
purchase shares under the Plan at such accelerated Offering Termination Date.

                                      -11-

 
21.    Registration and Qualification of the Plan under Applicable Securities 
       ----------------------------------------------------------------------
       Laws.
       ----

       No Option shall be granted under the Plan until such time as the Company
has qualified and registered the shares which are subject to the Option under
the applicable state and federal securities laws to the extent required by such 
laws.

                                      -12-