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                                                                  Exhibit 10.21


                              EMPLOYMENT AGREEMENT

         THIS EMPLOYMENT AGREEMENT (the "Agreement"), made this day of July,
1999, is entered into by Open Market, Inc., a Delaware corporation with its
principal place of business at 1 Wayside Road, Burlington, MA 01803 (the
"Company"), and Ron Matros, residing in Marlborough, MA (the "Employee").

         Concurrently with the execution and delivery of this Agreement, Open
Market, Inc., Acquisition Corp., a Delaware corporation ("MergerSub"), and
FutureTense, Inc., a Delaware corporation ("FutureTense, Inc."), have executed
and delivered an Agreement and Plan of Merger dated as of July , 1999 (the
"Merger Agreement"), providing for the merger of MergerSub into FutureTense,
Inc., whereby FutureTense, Inc. shall be a wholly-owned subsidiary of the
Company immediately following the Effective Time (as defined in the Merger
Agreement) (the "Merger").

         In connection with the transactions contemplated by the Merger
Agreement, the Company desires to employ the Employee, and the Employee desires
to be employed by the Company. In consideration of the mutual covenants and
promises contained herein, and other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged by the parties hereto,
the parties agree as follows:

     1.   TERM OF EMPLOYMENT. The Company hereby agrees to employ the Employee,
and the Employee hereby accepts employment with the Company, upon the terms set
forth in this Agreement, for the period commencing on the Effective Date (as
defined in the Merger Agreement) (the "Commencement Date") and ending upon
termination of employment in accordance with Section 4,: If the Merger is not
consumated, this Agreement becomes null and void.

     2.   TITLE; CAPACITY. The Employee shall serve as a Section 16(b) officer
of the Company (and will be required, as a condition of employment, to sign the
Executive Retention Agreement attached hereto as Attachment A), a member of the
Company's Board of Directors, and President and Chief Operating Officer or in
such other similar position as the Company may determine from time to time. The
Employee shall be based at the Company's headquarters in Burlington or Acton,
Massachusetts, or such place within twenty (20) miles of Burlington or Acton,
Massachusetts as the CEO shall determine. The Employee shall be subject to the
supervision of, and shall have such authority as is delegated to him by Gary
Eichhorn, Chief Executive Officer, or his successor.

         The Employee hereby accepts such employment and agrees to undertake the
duties and responsibilities inherent in such position and such other reasonably
consistent duties and responsibilities as the Chief Executive Officer shall from
time to time reasonably assign to him. The Employee agrees to devote his entire
business time, attention and energies to the business and interests of the
Company during the Employment Period; provided, however, that nothing herein
shall be construed as preventing the Employee from making personal investments,
and provided, further, that nothing herein shall be construed as preventing the
Employee from serving on civic or

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charitable boards, so long as the Employee has obtained permission to do so in
each instance and in advance from the Chief Executive Officer. The Employee
agrees to abide by the rules, regulations, instructions, personnel practices and
policies of the Company and any changes therein which may be adopted from time
to time by the Company.

     3.   COMPENSATION AND BENEFITS.

          3.1  SALARY. The Company shall pay the Employee, in semi-monthly
installments, an annual base salary of $205,000 for the one-year period
commencing on the Commencement Date. Such salary shall be subject to adjustment
thereafter as determined by the CEO or his successor.

          3.2  FRINGE BENEFITS. The Employee shall be entitled to participate in
all bonus and benefit programs that the Company establishes and makes available
to its employees, if any, to the extent that Employee's position, tenure,
salary, age, health and other qualifications make him eligible to participate,
including, but not limited to, the Company's 1999 Executive Short Term Incentive
Plan attached hereto as Attachment B. The Employee shall be entitled to 3 weeks
paid vacation per year, to be taken at such times as may be approved by the CEO.

          3.3  REIMBURSEMENT OF EXPENSES. The Company shall reimburse the
Employee for all reasonable travel, entertainment and other expenses incurred or
paid by the Employee in connection with, or related to, the performance of his
duties, responsibilities or services under this Agreement, upon presentation by
the Employee of documentation, expense statements, vouchers and/or such other
supporting information as the Company may reasonably request, PROVIDED, HOWEVER,
that the amount available for such travel, entertainment and other expenses may
be fixed in advance by the CEO.

          3.4  OPTIONS. The Company agrees to grant to Employee under its 1994
Incentive Stock Option Plan an option to purchase up to 250,000 shares of its
Common Stock, $.001 par value per share, at a price per share equal to the fair
market value of the shares of Common Stock of the Company at the time of grant,
which option shall vest ratably over a four-year period and shall be subject to
the terms and conditions of the Company's standard form of Option Agreement. To
the extent permissable under applicable law and under the 1994 Incentive Stock
Option Plan, such options shall be incentive stock options. The grant of options
pursuant to this Section 3.4 shall be approved by the Board on or before the
Effective Date and the options shall issue promptly after the Effective Date.

          3.5  BONUS. Employee shall be entitled to participate in the Company's
1999 Executive Short Term Incentive Plan pursuant to which Employee shall be
paid (a) a minimum bonus of $75,000 for the year ending December 31, 1999 to be
paid in the first pay period following December 31, 1999 and (b) a minimum bonus
of $125,000 for the year ending December 31, 2000 to be paid no later than April
1, 2000 (the "Year 2000 Bonus"). However, if pursuant to the terms of the
Company's 1999 Executive Short Term Incentive Plan, Employee is not entitled to
receive the Year 2000 Bonus (or any portion thereof), Employee shall repay the
Company any amount in excess of $75,000 (up to a maximum of $50,000), such
payment to be made no later than January 31, 2001. "

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     4.   EMPLOYMENT TERMINATION. The employment of the Employee by the Company
pursuant to this Agreement shall terminate upon the occurrence of any of the
following:

          4.1  At the election of the Company, for cause, immediately upon
written notice by the Company to the Employee. For the purposes of this Section
4.1, cause for termination shall be deemed to exist upon (a) a good faith
finding by the CEO of the material failure of the Employee to perform his
assigned duties for the Company, which failure is not cured within thirty (30)
days after a written demand for performance is delivered to the Employee by the
CEO which specifically identifies the manner in which the CEO believes that the
Employee has not performed his duties; (b) the Employee's dishonesty, gross
negligence or willful misconduct, or (c) the conviction of the Employee of, or
the entry of a pleading of guilty or nolo contendere by the Employee to, any
crime involving moral turpitude or any felony;

          4.2  Thirty days after the death or disability of the Employee. As
used in this Agreement, the term "disability" shall mean the inability of the
Employee, due to a physical or mental disability, for a period of 90 days,
whether or not consecutive, during any 360-day period to perform the services
contemplated under this Agreement. A determination of disability shall be made
by a physician satisfactory to both the Employee and the Company, PROVIDED THAT
if the Employee and the Company do not agree on a physician, the Employee and
the Company shall each select a physician and these two together shall select a
third physician, whose determination as to disability shall be binding on all
parties;

          4.3  At the election of the Company at any time after the first
anniversary of the Commencement Date, provided the Company gives the Employee at
least 30 days advanced written notice;

          4.4  At the election of the Employee at any time after the first
anniversary of the Commencement Date, provided the Employee gives the Company at
least 30 days advanced written notice;

          4.5  At the election of the Employee at any time for Good Reason. For
purposes of this Agreement, "Good Reason" shall mean the termination of
employment by the Employee as a result of (a) a material breach of the
Employment Agreement by the Company; or (b) a material reduction in the
Employee's responsibilities.

     5.   EFFECT OF TERMINATION.

          5.1  TERMINATION FOR CAUSE OR AT ELECTION OF THE EMPLOYEE AFTER THE
FIRST ANNIVERSARY. In the event the Employee's employment is terminated for
cause pursuant to Section 4.1, or at the election of the Employee pursuant to
Section 4.4, the Company shall pay to the Employee the compensation and benefits
otherwise payable to him under Section 3 through the last day of his actual
employment by the Company.

          5.2  TERMINATION AT ELECTION OF THE COMPANY AFTER THE FIRST
ANNIVERSARY. In the event the Employee's employment is terminated at the
election of the Company pursuant to Section 4.3, the Company shall pay to the
Employee an amount equal to six months of his base salary as severance pay. No
payment hereunder will be required unless and until the parties enter into a
release agreement pursuant to which the Employee releases the

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Company from any and all claims related to his employment with or termination
from the Company, and any payment hereunder will be made in accordance with the
Company's regular payroll practices.

          5.3  TERMINATION FOR GOOD REASON OR AT ELECTION OF COMPANY PRIOR TO
FIRST ANNIVERSARY. In the event the Employee's employment is terminated prior to
the first anniversary of the Commencement Date either at the election of the
Employee for good reason pursuant to Section 4.5 or at the election of the
Company other than for cause, the Company shall continue to pay the Employee his
base salary as severance pay until the first anniversary of the Commencement
Date or an amount equal to six months of his base salary as severance pay,
whichever is greater.

          5.4  TERMINATION FOR DEATH OR DISABILITY. If the Employee's employment
is terminated by death or because of disability pursuant to Section 4.2, the
Company shall pay to the estate of the Employee or to the Employee, as the case
may be, the compensation which would otherwise be payable to the Employee up to
the end of the month in which the termination of his employment because of death
or disability occurs.

          5.5  SURVIVAL. The provisions of Sections 6 and 7 shall survive the
termination of this Agreement.

     6.   NON-COMPETE.

          6.1  During the Employment Period and for a period of two years after
the termination or expiration thereof, the Employee will not directly or
indirectly: (i) as an individual proprietor, partner, stockholder, officer,
employee, director, joint venturer, investor, lender, or in any other capacity
whatsoever (other than as the holder of not more than one percent (1%) of the
total outstanding stock of a publicly held company), engage in the business of
developing, producing, marketing or selling software products or services in the
Internet commerce industry or content management or epublishing business that
are or would be directly competitive with products or services offered or under
development by the Company while the Employee was employed by the Company; or
(ii) recruit, solicit or induce, or attempt to induce, any employee or employees
of the Company to terminate their employment with, or otherwise cease their
relationship with, the Company; or (iii) solicit for the purpose of providing
any product or service competitive with the products or services offered by the
Company, divert or take away, or attempt to divert or to take away, the business
or patronage of any of the clients, customers or accounts, or prospective
clients, customers or accounts, of the Company which were contacted, solicited
or served by the Employee while employed by the Company.

          6.2  If any restriction set forth in this Section 6 is found by any
court of competent jurisdiction to be unenforceable because it extends for too
long a period of time or over too great a range of activities or in too broad a
geographic area, it shall be interpreted to extend only over the maximum period
of time, range of activities or geographic area as to which it may be
enforceable.

          6.3  The restrictions contained in this Section 6 are necessary for
the protection of the business and goodwill of the Company and are considered by
the Employee to be reasonable for such purpose. The Employee agrees that any
breach of this Section 6 will cause the Company substantial and irrevocable
damage and

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therefore, in the event of any such breach, in addition to such other remedies
which may be available, the Company shall have the right to seek specific
performance and injunctive relief.

     7.   PROPRIETARY INFORMATION AND DEVELOPMENTS.

          7.1  PROPRIETARY INFORMATION.

               (a)  Employee agrees that all information and know-how, whether
or not in writing, of a private, secret or confidential nature concerning the
Company's technology business or financial affairs (collectively, "Proprietary
Information") is and shall be the exclusive property of the Company. By way of
illustration, but not limitation, Proprietary Information may include
inventions, products, processes, methods, techniques, formulas, compositions,
compounds, projects, developments, plans, research data, clinical data,
financial data, personnel data, computer programs, and customer and supplier
lists. Employee will not disclose any Proprietary Information to others outside
the Company or use the same for any unauthorized purposes without written
approval by an officer of the Company, either during or after his employment,
unless and until such Proprietary Information has become public knowledge
without fault by the Employee.

               (b)  Employee agrees that all files, letters, memoranda, reports,
records, data, sketches, drawings, laboratory notebooks, program listings, or
other written, photographic, or other tangible material containing Proprietary
Information, whether created by the Employee or others, which shall come into
his custody or possession, shall be and are the exclusive property of the
Company to be used by the Employee only in the performance of his duties for the
Company.

               (c)  Employee agrees that his obligation not to disclose or use
information, know-how and records of the types set forth in paragraphs (a) and
(b) above, also extends to such types of information, know-how, records and
tangible property of customers of the Company or suppliers to the Company or
other third parties who may have disclosed or entrusted the same to the Company
or to the Employee in the course of the Company's business.

          7.2  DEVELOPMENTS.

               (a)  Employee will make full and prompt disclosure to the Company
of all inventions, improvements, discoveries, methods, developments, software,
and works of authorship, whether patentable or not, which are created, made,
conceived or reduced to practice by the Employee or under his direction or
jointly with others during his employment by the Company, whether or not during
normal working hours or on the premises of the Company (all of which are
collectively referred to in this Agreement as "Developments").

               (b)  Employee agrees to assign and does hereby assign to the
Company (or any person or entity designated by the Company) all his right, title
and interest in and to all Developments and all related patents, patent
applications, copyrights and copyright applications. However, this Section 7(b)
shall not apply to Developments which do not relate to the present or planned
business or research and development of the Company and which are made and
conceived by the Employee not during normal working hours, not on the Company's
premises and not using the Company's tools, devices, equipment or Proprietary
Information.

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               (c)  Employee agrees to cooperate fully with the Company, both
during and after his employment with the Company, with respect to the
procurement, maintenance and enforcement of copyrights and patents (both in the
United States and foreign countries) relating to Developments. Employee shall
sign all papers, including, without limitation, copyright applications, patent
applications, declarations, oaths, formal assignments, assignment of priority
rights, and powers of attorney, which the Company may deem necessary or
desirable in order to protect its rights and interests in any Development.

          7.3  OTHER AGREEMENTS. Employee hereby represents that he is not bound
by the terms of any agreement with any previous employer or other party to
refrain from using or disclosing any trade secret or confidential or proprietary
information in the course of his employment with the Company or to refrain from
competing, directly or indirectly, with the business of such previous employer
or any other party. Employee further represents that his performance of all the
terms of this Agreement and as an employee of the Company does not and will not
breach any agreement to keep in confidence proprietary information, knowledge or
data acquired by him in confidence or in trust prior to his employment with the
Company.

     8.   NOTICES. All notices required or permitted under this Agreement shall
be in writing and shall be deemed effective upon personal delivery or upon
deposit in the United States Post Office, by registered or certified mail,
postage prepaid, addressed to the other party at the address shown above, or at
such other address or addresses as either party shall designate to the other in
accordance with this Section 8.

     9.   PRONOUNS. Whenever the context may require, any pronouns used in this
Agreement shall include the corresponding masculine, feminine or neuter forms,
and the singular forms of nouns and pronouns shall include the plural, and vice
versa.

     10.  ENTIRE AGREEMENT. This Agreement, together with its attachments,
constitutes the entire agreement between the parties and supersedes all prior
agreements and understandings, whether written or oral, relating to the subject
matter of this Agreement. In the event of a Change in Control, as defined in the
Executive Retention Agreement attached hereto as Attachment A, the provisions of
Attachment A shall supersede any provisions of this Agreement concerning the
same subject matter.

     11.  AMENDMENT. This Agreement may be amended or modified only by a written
instrument executed by both the Company and the Employee.

     12.  GOVERNING LAW. This Agreement shall be construed, interpreted and
enforced in accordance with the laws of the Commonwealth of Massachusetts.

     13.  SUCCESSORS AND ASSIGNS. This Agreement shall be binding upon and inure
to the benefit of both parties and their respective successors and assigns,
including any corporation with which or into which the Company may be merged or
which may succeed to its assets or business, provided, however, that the
obligations of the Employee are personal and shall not be assigned by him.

     14.  MISCELLANEOUS.

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          14.1 No delay or omission by the Company in exercising any right under
this Agreement shall operate as a waiver of that or any other right. A waiver or
consent given by the Company on any one occasion shall be effective only in that
instance and shall not be construed as a bar or waiver of any right on any other
occasion.

          14.2 The captions of the sections of this Agreement are for
convenience of reference only and in no way define, limit or affect the scope or
substance of any section of this Agreement.

          14.3 In case any provision of this Agreement shall be invalid, illegal
or otherwise unenforceable, the validity, legality and enforceability of the
remaining provisions shall in no way be affected or impaired thereby.

     15.  REQUIRED APPROVALS. The Company and the Employee hereby acknowledge
and agree that this agreement shall not take effect until the above terms and
conditions have been approved by the Company's Board of Directors.

         IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the day and year set forth above.


         Open Market, Inc.

         By: /s/ Gary Eichhorn
             -----------------

         Title: Chief Executive Officer


         EMPLOYEE

         /s/ Ronald J. Matros
         --------------------