10.20 Executive Employment Agreement dated November 19, 1998 between ODI and
Lawrence Alston

                         EXECUTIVE EMPLOYMENT AGREEMENT

This Employment Agreement (the "Agreement") dated as of November 19, 1998 by and
between Object Design, Inc., a Delaware corporation with its principal offices
located at 25 Mall Road, Burlington, MA 01803 ("ODI") and Lawrence Alston, an
individual residing at 7 Morningside Ave., Natick, MA 01760 (the "Executive").

WHEREAS, ODI has offered employment to the Executive, and Executive has accepted
employment by ODI, as Vice President, Marketing;

NOW, therefore, ODI and the Executive agree as follows:

1.   Termination of Employment and Severance

          (a) Termination for Cause. If the Executive is terminated by ODI for
          Cause, there shall be no Separation Benefits (as hereinafter defined).
          For the purposes of this Agreement, "Cause" shall mean:

               (i) The Executive's material breach in respect to his assigned
               duties, and compliance with any and all policies, directives,
               standards and regulations adopted by ODI, including without
               limitation compliance with the terms and conditions of the
               attached NON-COMPETITION, NON-SOLICITATION, NON-DISCLOSURE AND
               DEVELOPMENTS AGREEMENT and ODI's Insider Trading Policy, such
               breach continuing unremedied for thirty (30) days after written
               notice thereof from ODI to the Executive specifying the acts
               constituting the breach and requesting that they be remedied; or

               (ii) Any dishonesty or other malicious act by the Executive
               materially detrimental to the goodwill of ODI, or materially
               damaging to ODI's relationships with its customers or employees,
               including without limitation, the Executive having been convicted
               of a felony during the term of his employment with ODI.

          (c) Voluntary Termination by the Executive. If the Executive
          voluntarily terminates his employment for any reason, including
          without limitation death and disability, there shall be no Separation
          Benefits (as hereinafter defined). Notwithstanding the foregoing, in
          the event of a Change of Control (as hereinafter defined) where the
          Executive's compensation, duties and/or responsibilities are
          materially reduced from those currently exercised by the Executive
          with ODI and/or ODI requires the Executive to be based at any office
          or location other than ODI's principal place of business, the
          Executive may voluntarily terminate his employment with ODI or a
          successor and shall be entitled to receive the Separation Benefits (as
          hereinafter defined).

          (d) Termination by ODI due to a Change in Control If ODI terminates
          the Executive's employment within twelve (12) months after a Change in
          Control (which shall mean (a) the acquisition by an individual,
          entity, group or any other person of beneficial ownership of
          thirty-five percent (35%) or more of either (i) the then-outstanding
          shares of common stock of ODI or (ii) the combined voting power of the
          election of directors for ODI; and/or (b) the sale of substantially
          all of ODI's assets or a merger or sale of stock wherein the holders
          of ODI's capital stock immediately prior to such sale do not hold at
          least a majority of the outstanding capital stock of ODI or its
          successor immediately following
<PAGE>

          such sale; and/or (c) individuals who, as of the date hereof,
          constitute the Board of Directors (the "Incumbent Board") cease for
          any reason to constitute at least a majority of the Board of
          Directors, provided, however, that any individual becoming a director
          subsequently to the date hereof whose election, or nomination for
          election by ODI's shareholders, was approved by a vote of at least a
          majority of the directors then comprising the Incumbent Board shall be
          considered as though such individual were a member of the Incumbent
          Board, but excluding, for this purpose, any such individual whose
          initial assumption of office occurs as result of an actual or
          threatened election contest with respect to the election or removal of
          directors or other actual or threatened solicitation of proxies or
          consents by or on behalf of a person other than the Board of
          Directors), ODI shall pay to the Executive the Separation Amount (as
          hereinafter defined) on the effective date of such termination. The
          Separation Amount shall be equal to the sum of (i) the Executive's
          then-current monthly salary multiplied by twelve (12), plus (ii) one
          hundred (100) percent of the maximum performance bonus amount,
          including without limitation any and all commissions, pursuant to
          existing compensation agreements in effect for the year in which such
          termination occurs which the Executive could have earned if he
          remained in the employ of ODI and all performance goals and other
          criteria were met (whether or not such goals or criteria are in fact
          met) multiplied by one (1), and payable in one lump sum upon the date
          of termination. In addition to the Separation Amount, ODI shall
          provide the Executive with the following additional benefits: for
          twelve (12) months following the effective date of such termination
          due to a Change in Control, ODI shall continue to pay and provide to
          the Executive medical and dental insurance benefits consistent with
          those provided to the Executive immediately prior to such termination,
          provided, however, that if the Executive becomes re-employed with
          another employer and is eligible to receive such insurance benefits
          under another employer-provided plan, the insurance benefits set forth
          herein shall be secondary to those provided under such other plan
          during such applicable period of eligibility (such additional benefits
          under this paragraph, together with the Separation Amount, are
          hereinafter referred to as the "Separation Benefits").

2.   Effect of a Change in Control of ODI

          (a) Acceleration of Vesting of Stock Options Upon any Change in
          Control, any and all options granted to the Executive under any ODI
          stock option plan shall be deemed immediately vested upon the date of
          such Change in Control.

          (b) Assumption of Obligations Hereunder ODI shall require any
          successor via a Change in Control (whether direct or indirect, by
          purchase, merger, consolidation or otherwise) to assume expressly and
          agree to perform this Agreement in the same manner and to the same
          extent that ODI would be required to perform it if no such succession
          had taken place.

3.   Executive's Responsibilities

          As a condition precedent to ODI's obligations hereunder, the Executive
          shall enter into the attached NON-COMPETITION, NON-SOLICITATION,
          NON-DISCLOSURE AND DEVELOPMENTS AGREEMENT with ODI, which is
          incorporated herein by reference.
<PAGE>

4.  Miscellaneous

          (a) Provision of Full Settlement Except as set forth herein, ODI's
          obligation to make the payments provided for in this Agreement and
          otherwise to perform its obligations hereunder shall not be affected
          by any set-off, counterclaim, recoupment, defense or other claim,
          right or action which ODI may have against the Executive (under this
          Agreement or otherwise) or others. In no event shall the Executive be
          obligated to seek other employment or take any other action by way of
          mitigation of the amounts payable to the Executive under any of the
          provisions of this Agreement and such amounts shall not be reduced
          whether or not the Executive obtains other employment.

          (b) Amounts Payable Less Withholding Taxes The amounts payable by ODI
          hereunder shall be less any federal, state or local withholding taxes
          and social security.

          (c) Excise Tax To the extent that payments or other benefits to the
          Executive pursuant to this Agreement (together with any other payments
          or benefits, stock awards received by the Executive in connection with
          a Change in Control) would result in triggering the provisions of the
          Sections 280G and 4999 of the Code, this Agreement provides for the
          payment of an additional amount such that the Executive receives, net
          of excise taxes, the amount he would have been entitled to receive in
          the absence of the excise tax provided in Section 4999 of the Code.

          (d) Notice All notices, requests, demands and other communications
          hereunder must be in writing and shall be deemed to have been duly
          given if delivered by hand or mailed, within the continental United
          States by first class, registered mail, receipt requested, postage and
          registry fees prepaid, to the applicable party at the address set
          forth above or at such other address as is provided by a party
          pursuant to the terms hereof.

          (e) Entire Agreement. This Agreement embodies the entire
          understanding, and supersedes all other oral or written agreements or
          understandings, between the parties regarding the subject matter
          hereof, including without limitation any terms and conditions of any
          employment agreement or other similar agreement. No change, alteration
          or modification hereof may be made except in a writing signed by both
          parties hereto. This Agreement and the rights and obligations of the
          parties hereunder shall be construed in accordance with and governed
          by the laws of The Commonwealth of Massachusetts (disregarding any
          choice of law rules which may look to the laws of any other
          jurisdiction).


IN WITNESS WHEREOF, the parties hereto have executed and delivered this
Agreement as of the day and year first above written.

                                            OBJECT DESIGN, INC.

                                            By: /s/ Robert Goldman
                                                ------------------

                                            Its: Chief Executive Officer

                                            /s/ Lawrence Alston
                                                Lawrence Alston
<PAGE>

                NON-COMPETITION, NON-SOLICITATION, NON-DISCLOSURE
                           AND DEVELOPMENTS AGREEMENT

In consideration of my employment, consulting or advisory relationship
("Employment"), as the case may be, with Object Design, Inc., a Delaware
corporation with its principal place of business located at 25 Mall Road,
Burlington, Massachusetts 01803 (the "Company"), and in recognition of the fact
that as a result of such relationship I will or may have access to confidential
information, I agree with the Company as follows:

1.   Non-Compete and Non-Solicitation Agreement

(a) As long as I am employed or retained by the Company and for a period of one
year after the termination of my Employment with the Company by me or the
Company for any reason, including expiration of the previously agreed upon term
of my Employment, or by the Company for Cause (as defined in the Executive
Employment Agreement), I shall not, directly or indirectly, on my behalf or on
behalf of any third-party, or as owner, manager, stockholder, consultant,
director, officer or employee of any business entity, participate in the
development, manufacture, license, provision or sale of any goods or services
which are competitive with goods or services sold or licensed, or under
development, by the Company without the prior written authorization of the
Company; provided, however, that I may, without the Company's prior written
authorization, own up to one percent (1%) of the issued and outstanding
securities of any publicly held corporation or any securities in any non-public
corporation which I owned prior to the date of my Employment.

         (i) In the event that the Company and I disagree about whether any
business entity develops or provides goods or services which are competitive
with goods or services sold or licensed, or under development, by the Company,
the disagreement shall be resolved either by decision of the Company's Board of
Directors at their next regularly scheduled board meeting acting in good faith
after giving me a suitable opportunity to present my view in person and/or in
writing, or if either I or the Company gives notice to the Board of our
objection to the decision of the Board within 30 days after such decision, by
arbitration as provided herein.

         (ii) The Company and I agree that goods or services which are
competitive with goods or services developed or provided, or under development,
by the Company shall not include goods and services used by any person or entity
for use as a component in a good or service which is not competitive with goods
or services developed or provided, or under development, by the Company.

         (iii) If after the commencement of my Employment with the Company the
Company determines to change its line of business so as to provide goods or
services other than those sold or licensed, or under development, by the Company
at the commencement of my Employment, then the Company shall give me notice of
such determination.

(b) Except with the prior written consent of the Company, during my employment
with the Company and for a period of one year after that employment ends for any
reason, including expiration of the previously agreed upon term of my
Employment, or by the Company for Cause, I will not directly or indirectly,
either for myself or for any other entity or third-party, or as owner, manager,
stockholder, consultant, director, officer or employee of any business entity,
take away any of the customers that the Company had enjoyed during my Employment
with the Company.
<PAGE>

(c) Except with the prior written consent of the Company, during my employment
with the Company and for a period of one year after that employment ends for any
reason, including expiration of the previously agreed upon term of my
Employment, or by the Company for Cause, I shall not directly or indirectly,
either for myself or for any other entity or third-party, or as owner, manager,
stockholder, consultant, director, officer or employee of any business entity,
solicit, induce or attempt to hire away from the Company any employee of the
Company (or any other person who may have been employed by the Company during
the six months prior to the termination of my Employment), or assist in such
hiring by any other person or business entity or encourage any such employee to
terminate his or her employment with the Company.

(d) I recognize that the Company is developing highly specialized products and
services in competition with other business entities throughout the United
States and the world, which products and services are designed to compete in
regional, nation-wide and world-wide markets. In light of the competitive nature
of the Company's products and services, I agree that the restrictions contained
in this Section 1 cannot be limited to any geographic area, and I further
recognize that the restrictions set forth in this Section 1 are intended to
protect the Company's interests in its Confidential Information and established
commercial relationships and goodwill, and agree that such restrictions are
reasonable and appropriate for this purpose.

(e) If the period of time, geographic area, or other term of any non-competition
or non-solicitation restraint specified in this Agreement is judged by a court
to be unreasonable, I agree that such term should be modified by the court so
that the term can be enforced as the court decides is reasonable.

(f) If I violate any non-competition or non-solicitation restraint specified in
this Agreement, I agree that the period of the restraint shall not run during
the period of the violation. I understand that the purpose of this paragraph is
to give the Company the protection of the restraint for the full agreed-upon
duration.

2.   Confidentiality Agreement

(a) I acknowledge that in the course of my employment, I will gain access to and
may gain possession of Confidential Information of the Company. The term
"Confidential Information" as used throughout this Agreement shall mean all
trade secrets, proprietary information and other data or information (and any
tangible evidence, record or representation thereof), whether prepared,
conceived or developed by an employee of the Company (including myself) or
received by the Company from an outside source, which is in the possession of
the Company (whether or not the property of the Company), which in any way
relates to the present or future business of the Company or any customer or
supplier of the Company, and/or which is maintained in confidence by the
Company. Without limiting the generality of the foregoing, "Confidential
Information" shall mean all trade secrets, know-how, proprietary information and
other information or data relating to the present or future business of the
Company, including but not limited to:

                  (i) any idea, improvement, invention, innovation, development,
technical data, design, formula, device, pattern, concept, computer program,
software, firmware, source code, object code, algorithm, subroutine, object
module, schematic, model, diagram, flow chart, chip masking specification, user
manual, training or service manual, product specification, plan for a new or
revised product, compilation of information, or work in process, and any and all
revisions and improvements relating to any of the foregoing (in each case
whether or not reduced to tangible form); and
<PAGE>

                  (ii) the name of any customer, employee, prospective customer
or consultant, any sales plan, marketing material, plan or survey, business plan
or projections, customer list, product or development plan or specification,
business proposal, financial record, business record, advertiser lists, supplier
lists, customer sales analyses, price lists and any other non-public information
or other record relating to the business of the Company.

Notwithstanding the foregoing, the term Confidential Information shall not apply
to information which has otherwise lawfully entered the public domain, or is
generally known in the industry.

(b) I agree to keep all Confidential Information strictly confidential and not
to use Confidential Information for any purpose or disclose Confidential
Information, including Confidential Information of any third party which the
Company is under an obligation to keep confidential, to any person or entity
during my employment, except as expressly authorized by and for the benefit of
the Company and in the course of my duties as an employee, or at any time after
my employment ends. As part of my obligations to maintain the confidentiality of
Confidential Information, I agree to comply with any Company policy, if any, on
the protection of intellectual property. I further agree that after the
termination and/or expiration of my employment, I shall not use or permit the
use of any Confidential Information, it being agreed that all Confidential
Information shall be and remain the sole and exclusive property of the Company
and that within ten (10) days after the termination or expiration of my
employment I shall either (i) deliver all Confidential Information, and all
copies thereof, to the Company, at its main office or (ii) destroy all
Confidential Information, and all copies thereof, and deliver a sworn notice to
the Company certifying to such destruction.

(c) I hereby represent that my performance of all of the terms of this Agreement
and as an employee, consultant or advisor of the Company does not and will not
breach any agreement to keep in confidence Confidential Information acquired by
me prior to my Employment by the Company. I have not entered into, and I agree I
will not enter into, any agreement either written or oral in conflict herewith.

3.   Developments Agreement

(a) If at any time or times during my Employment, I shall (either alone or with
others) make, conceive, learn, discover or reduce to practice any invention,
modification, discovery, design, development, improvement, process, software
program, work of authorship, documentation, formula, data, technique, know-how,
secret, concept, idea, and fixed expression thereof or any interest therein
(whether or not patentable or registrable under copyright, patent, trademark or
similar statutes or subject to analogous protection) (herein called
"Developments") that relate to the business of the Company, whether directly or
indirectly, and/or that relate to software provided by suppliers to the Company
and incorporated in the Company's products, or any of the goods and services
sold, licensed or under development by the Company; and/or result from the use
of premises, facilities or personal property tangible or intangible owned,
leased or contracted for by the Company; and/or that occur during the period of,
as a consequence of, or in connection with my employment by the Company; and/or
that result from tasks assigned to me by the Company; such Developments and the
benefits thereof shall immediately become the sole and absolute property of the
Company and its assigns, and I shall promptly disclose to the Company (or any
persons designated by it) each such Development and hereby assign any rights I
may have or acquire in the Developments and benefits and/or rights resulting
therefrom to the Company and its assigns without further compensation and waive
any and all moral rights to all Developments. All Developments shall be the sole
property of the Company and its assigns. The Company shall be
<PAGE>

the sole owner of all patents, copyrights and other rights relating to
Developments. I acknowledge that all Developments are "work(s) made for hire",
as defined under the United States Copyright Act, and become the property of the
Company, and shall communicate, without cost or delay, and without publishing
the same, all available information relating thereto (with all necessary plans
and models) to the Company.

(b) Upon disclosure of each Development to the Company, I will, during my
Employment and at any time thereafter, at the request and cost of the Company,
sign, execute, make and do all such deeds, documents, acts and things as the
Company and its duly authorized agents may reasonably require:

         (i) to apply for, obtain and vest in the name of the Company alone
(unless the Company otherwise directs) letters of patent, copyrights or other
analogous protection in any country throughout the world and when so obtained or
vested to renew and restore the same; and

         (ii) to defend any opposition proceedings in respect of such
applications and any opposition proceedings or petitions or applications for
revocation of such letters of patent, copyright or other analogous protection.

In the event the Company is unable, after reasonable effort, to secure my
signature on any letters of patent, copyright or other analogous protection
relating to a Development, whether because of my physical or mental incapacity
or for any other reason whatsoever, I hereby irrevocably designate and appoint
the Company and its duly authorized officers and agents as my agent and
attorney-in-fact, to act for and in my behalf and stead to execute and file any
such application or applications and to do all other lawfully permitted acts to
further the prosecution and issuance of letters of patent, copyright or other
analogous protection thereon with the same legal force and effect as if executed
by me.

(c) This Section 3 shall not apply to any Development which meets all of the
following three conditions: (i) I do the work entirely by myself without use of
the Company's facilities, knowledge, property or resources, (ii) I do the work
entirely on my own time, and (iii) the Development does not relate, either,
directly or indirectly, to the Company's business or research or to its planned
business or research.

4.   Miscellaneous

(a) I agree that because of the nature of the Company's business, the
restrictions contained in this Agreement are reasonable and necessary in order
to protect the legitimate interests of the Company.

(b) I understand that this Agreement does not create an obligation on the
Company or any other person or entity to continue my Employment.

(c) Any waiver by the Company of a breach of any provision of this Agreement
shall not operate or be construed as a waiver of any subsequent breach of such
provision or any other provision hereof.

(d) I hereby agree that each provision herein shall be treated as a separate and
independent clause, and the unenforceability of any one clause shall in no way
impair the enforceability of any of the other clauses herein. Moreover, if one
or more of the provisions contained in this Agreement shall for any reason be
held to be excessively broad as to scope, activity or subject so as to be
unenforceable at law, such provision or provisions shall be construed by the
appropriate
<PAGE>

judicial body by limiting and reducing it or them, so as to be enforceable to
the maximum extent compatible with the applicable law as it shall then appear.

(e) I recognize that money damages alone would not adequately compensate the
Company in the event of breach by me of this Agreement, and I therefore agree
that, in addition to all other remedies available to the Company at law or in
equity, the Company shall be entitled to injunctive relief for the enforcement
hereof. Failure by the Company to insist upon strict compliance with any of the
terms, covenants or conditions hereof shall not be deemed a waiver of such
terms, covenants or conditions.

(f) My obligations under this Agreement shall survive the termination or
expiration of my Employment regardless of the manner of termination, except that
the provisions of Section 1 shall survive in accordance with their terms.

(g) The term "Company" shall include Object Design, Inc. and any of its
subsidiaries, subdivisions or affiliates. The Company shall have the right to
assign this Agreement to its successor and assigns, and all covenants and
agreements hereunder shall inure to the benefit of and be enforceable by said
successors or assigns.

(h) This Agreement shall be governed by and construed in accordance with the
laws of the Commonwealth of Massachusetts (disregarding any choice of law rules
which may look to the laws of any other jurisdiction). In the event of any court
action to enforce any provision of this Agreement, The parties consent to and
submit to the jurisdiction of the Superior Court of the Commonwealth of
Massachusetts and the United States District Court for the District of
Massachusetts.

(i) This Agreement embodies the entire understanding, and supersedes all other
oral or written agreements or understandings, between the parties regarding the
subject matter hereof, including without limitation any terms and conditions of
any employment agreement or other similar agreement(s). No change, alteration,
modification, waiver or termination of this Agreement or any of the provisions
herein contained shall be binding upon me or the Company unless made in writing
and signed by myself and an authorized officer of the Company. In the event of
any inconsistency between this Agreement and any other contract between me and
the Company, the provisions of this Agreement shall prevail.

(j) All notices, requests, demands and other communications hereunder must be in
writing and shall be deemed to have been duly given if delivered by hand or
mailed, within the continental United States by first class, registered mail,
receipt requested, postage and registry fees prepaid, to the applicable party at
the address set forth below or at such other address as is provided by a party
pursuant to the terms hereof.

(k) Any controversy or claim arising out of or relating to this Agreement, or
the breach thereof, shall be settled by arbitration in Boston, Massachusetts in
accordance with the Commercial Arbitration Rules of the American Arbitration
Association, and judgment upon the award rendered by the arbitrator(s) may be
entered in any court having jurisdiction thereof and shall be final and binding
upon the parties hereto. Notwithstanding anything to the contrary contained in
this Section 4(k), the Company shall have the right to seek injunctive relief,
specific performance or other equitable relief against me in a court of
competent jurisdiction.
<PAGE>

BY PLACING MY SIGNATURE HEREUNDER, I ACKNOWLEDGE THAT I HAVE READ ALL OF THE
PROVISIONS OF THIS AGREEMENT AND THAT I AGREE TO ALL OF ITS TERMS.



                                                 /s/ Lawrence Alston
                                                 -------------------

                                                 Signature Lawrence Alston

                                                 Address:

                                                 7 Morningside Ave.

                                                 Natick, MA  01760


                                                 Date: 11/19/98


                                                 Accepted:

                                                 OBJECT DESIGN, INC.
                                                 25 Mall Road
                                                 Burlington, MA  01803


                                                 By: /s/ Robert Goldman
                                                     ------------------

                                                 Name: Robert Goldman

                                                 Title: Chief Executive Officer

                                                 Date: 11/19/98