EXHIBIT 10.25
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                            ON TECHNOLOGY CORPORATION
                                880 Winter Street
                                  Building Four
                             Waltham, MA 02451-1449


                                                          January 31, 2000


Mr. Robert L. Doretti
297 Commonwealth Avenue, No. 5
Boston, MA  02115

Dear Bob:

         On behalf of ON Technology Corporation (the "Company"), I am pleased to
offer you the position of President and Chief Executive Officer of the Company.
The terms of your employment relationship with the Company are as set forth
below, as approved by the Company's Board of Directors.

1.  POSITION. You will serve in a full-time capacity as President and Chief
Executive Officer of the Company, reporting to the Company's Board of Directors
and based in the Company's Waltham, Massachusetts office. As such, you will have
such responsibilities as are commensurate with your position and determined by
the Board. You will also be appointed a member of the Board at the first meeting
of the Board that follows the commencement of your employment with the Company.

2.  BASE SALARY, BENEFITS. You will be paid a base salary as determined by the
Board of Directors on an annual basis, at a rate of not less than $250,000. Your
salary will be payable in accordance with the Company's standard payroll
policies (subject to normal required withholding). You will receive a vacation
package comparable to that provided for key executives and will be eligible to
participate in the Company's life, disability, medical, dental and other
insurance programs available to key executives ("Benefits"). In addition, the
Compensation Committee of the Company's Board of Directors ("Compensation
Committee") will use good faith efforts to obtain post-employment health
insurance for you and your spouse upon your termination of employment at
retirement age in accordance with Company policy or upon your death or
disability, so long as the aggregate cost of such health insurance to the
Company, after any employee contribution, is not significant and does not
require any payment of premiums for more than two years after the date of this
letter. Alternatively, the Company and you may agree upon other arrangements
having a comparable purpose and cost. Any such post-retirement health insurance
is included in "Benefits".

3.  SIGN-ON BONUS. Effective with the commencement of your employment with the
Company, you will receive a stock option having the following terms:

         Option Shares:             0.25% of the outstanding common stock of the
                                    Company (36,732 shares).

         Exercise Price:            Market price on date of grant.
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         Vesting:                   Vested immediately in full.

         Stock                      Restriction: Stock purchased pursuant to
                                    this option before the first anniversary of
                                    the grant will be subject to a repurchase
                                    option in favor of the Company at the
                                    Exercise Price if your employment with the
                                    Company is terminated by you without
                                    Constructive Termination (as defined below),
                                    or by the Company for Cause (as defined
                                    below), prior to the first anniversary of
                                    the grant.

4.  INCENTIVE PROGRAM. The Company has an incentive compensation program for key
executives ("Incentive Program") tied to performance against the quarterly and
annual plan ("Plan"). The Plan is adopted for each fiscal year by the
Compensation Committee, based upon recommendations by management. As Chief
Executive, you will have a critical input in establishing the Plan on an annual
basis; we expect that the Plan for calendar year 2000 will be developed under
your supervision during the 45-day period after your commencement of employment
and will be approved by the Compensation Committee promptly thereafter. Under
the Incentive Program, you will be eligible for an annual bonus equal to
$150,000 if the Company's performance meets the Plan objectives. The Incentive
Program will provide that you will receive a maximum bonus of 150% of your
annual base salary if the Company's performance reaches the requisite parameters
specified in the Plan.

5.  STOCK OPTION PERFORMANCE BONUS. You will receive a performance bonus in the
form of a stock option (the "Performance Stock Option") with the following
terms:

         Option Shares:             2.5% of the outstanding common stock of the
                                    Company (367,325 shares)

         Exercise Price:            Market price on date of grant.

         Vesting:                   Vested in full upon the seventh anniversary
                                    of the grant.

         Acceleration:              Vesting will be accelerated during the first
                                    and second fiscal years as follows: (a) for
                                    each of the eight fiscal quarters in
                                    calendar year 2000 and 2001, between 8% and
                                    10% of the Option Shares will be accelerated
                                    in a linear progression, corresponding with
                                    the Company achieving between 80% and 100%
                                    of the applicable fiscal quarter benchmark
                                    set forth in the Plan; and (b) for the
                                    entire fiscal years 2000 and 2001, options
                                    for between 8% and 10% of the Option Shares
                                    will be accelerated in a linear progression,
                                    corresponding with the Company achieving
                                    between 80% and 100% of the applicable
                                    fiscal year benchmark set forth in the Plan.
                                    For example, if the Company achieves 60% of
                                    the Plan in Q1, 85% in Q2, 100% in Q3, 110%
                                    in Q4, and 90% for the fiscal year, then the
                                    option would be accelerated 0%, 8.5%, 10%,
                                    10% and 9%, respectively, or a total of
                                    137,746 Option Shares for such fiscal year.
                                    If the Company exceeds Plan for one or more
                                    quarters or for a fiscal year, but the
                                    maximum percentage of Option Share
                                    acceleration (50%) has not been achieved for
                                    such fiscal year (due to below-Plan
                                    performance for other quarters or the fiscal
                                    year), then the Compensation Committee will
                                    include in its Incentive Program, in
                                    additional to the cash amounts referenced in
                                    Section 4,

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                                    some or all of the Option Shares that would
                                    have accelerated had the Plan for the
                                    applicable quarters or fiscal year been met.

6.  STOCK OPTION. You will be granted a stock option ("Time Vesting Option")
with the following terms:

         Option Shares:             3% of the outstanding common stock of the
                                    Company (440,790 shares).

         Exercise Price:            Market price on date of grant.

         Vesting:                   The nonqualified portion of the Option will
                                    be fully exercisable upon grant, subject to
                                    the Company's right to repurchase the shares
                                    issuable upon exercise of the option upon
                                    termination of your employment by the
                                    Company, which right lapses over four years
                                    as follows: 25% lapses upon the first
                                    anniversary of the grant and 75% lapses over
                                    the three years thereafter in equal
                                    quarterly increments. The incentive stock
                                    option portion of the Option will be a
                                    standard option subject to four year vesting
                                    in accordance with the schedule set forth in
                                    the previous sentence.

7.  NATURE OF STOCK OPTIONS. The Stock Options referenced in paragraphs 3, 5 and
6 above will be incentive stock options to the extent permitted by applicable
tax regulations. Options in excess of the incentive stock option limits will be
non-qualified stock options.

8.  OTHER INCENTIVE COMPENSATION. During your employment by the Company, you
will be eligible for additional awards under the Company's 1992 Employee and
Consultant Stock Option Plan, under any subsequent similar plans or under other
incentive programs or plans adopted from time to time by the Board of Directors,
as determined by the Compensation Committee or the Board of Directors.

9.  TERMINATION OF EMPLOYMENT. If your employment with the Company is terminated
by your death or disability or by the Company for any reason other than for
Cause, or in the case of Constructive Termination, you (or your estate) will be
entitled to receive (a) $250,000, paid as though you were still employed by the
Company over a period of 12 months in installments in accordance with the
Company's normal practices, (b) continued Benefits during the 12 months
following such termination, (c) 12 months of acceleration of vesting (or
comparable reduction in the Company's right to repurchase your shares with
respect to the nonqualified Time Vesting Option) and, if the termination of
employment occurs before the end of the second fiscal year after grant of the
Performance Stock Option, then the Company shall be deemed to have met 100% of
Plan for any remaining quarters and fiscal year in the 12 month period
commencing on such termination, including the quarter then in progress, but
excluding any quarter ending after such 12 month period, (d) an opportunity to
exercise your stock options during the period of 12 months (three months for
incentive stock options) following such termination to the extent vested in
accordance with section (c) above at the date of such termination, and (e) any
cash bonus earned but not yet paid for completed quarters and fiscal years under
the Plan as well as a prorated amount of the quarterly and annual cash bonus
pursuant to the Plan for the quarter and fiscal year during which termination of
your employment occurs, based on the number of days of the quarter or fiscal
year, as applicable, that you were employed by the Company. The Company will
obtain and maintain life insurance for the benefit

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of your estate to cover the exercise price of vested and unexercised stock
options held by you in the event of your death.

         You will not be entitled to any additional payments, salary, bonus or
benefits in the event of termination for Cause. For the purposes of this
Agreement, "Cause" means a determination by a majority of the Board in its
reasonable judgment (after providing written notice to you specifying in
reasonable detail the specific conduct that it considers to constitute cause and
stating the date, time and place for a special board meeting to consider the
same and after providing you and your counsel the opportunity to be heard at
such board meeting) that you have (a) engaged in acts in violation of the law,
(b) breached your fiduciary duty to the Company or duties of loyalty or care to
the Company, (c) willfully disobeyed the good faith, lawful policies or
instructions of the Board, or (d) violated the provisions of Paragraph 9 of this
Agreement. For the purposes of this Agreement, "Constructive Termination" means
a material diminution of duties, change in title or reporting relationship,
change in location or reduction in base salary or Benefits.

10. CHANGE OF CONTROL. The stock options described in this Agreement will
provide for 24 months acceleration of vesting (or comparable reduction in the
Company's right to repurchase your shares with respect to the nonqualified Time
Vesting Option) upon a Change of Control (as defined below) of the Company. In
addition, if the Change of Control occurs before the end of the second fiscal
year after grant of the Performance Stock Option, then the Company shall be
deemed to have met 100% of Plan for any remaining quarters and fiscal year in
the fiscal year during which such Change of Control occurs. For a period of 12
months following a Change of Control of the Company, if your employment is
terminated by the Company for any reason other than for Cause or is terminated
by Constructive Termination, you will be entitled to receive the severance
benefits set forth in Paragraph 8 above. For the purposes of this Agreement,
"Change of Control" means any sale of all or substantially all of the Company's
assets or any merger, consolidation or stock sales which results in the holders
of the Company's capital stock immediately prior to such transaction owning less
than 50% of the voting power of the Company's capital stock immediately after
such transaction.

11. STANDARD EMPLOYEE AGREEMENTS. Like all Company employees, you will be
expected to sign and comply with an Employee Confidentiality Agreement (the
"Employee NDA") which requires, among other provisions, the assignment of patent
and other intellectual property rights to any invention or other trade secrets
created during your employment with the Company and non-disclosure of
proprietary information. Your employment will be contingent upon and not be
deemed effective until you have executed and returned the Employee NDA to the
Company. In addition, you will abide by the Company's strict policy that
prohibits any new employee from using or bringing with him or her from any
previous employer any confidential information, trade secrets, or proprietary
materials or processes of such former employer. You also agree that, during the
term of your employment with the Company and for one year thereafter, you will
not actively engage in any other employment, occupation, consulting or other
business that directly or indirectly competes with the business in which the
Company is now involved or becomes involved during the term of your employment;
will not divert existing or prospective customers of the Company; will not
solicit or hire any Company employees; and will not engage in any other
activities that conflict with your obligations to the Company. You will also be
expected to sign stock option agreements in form and substance satisfactory to
the Company for the stock options described in this Agreement.

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12. BUSINESS EXPENSES. You will be entitled to reimbursement by the Company for
all reasonable business expenses that you incur or pay in the performance of
your duties and responsibilities hereunder (including but not limited to travel
and automobile), subject to such reasonable substantiation and documentation as
may be specified by the Company from time to time.

13. AT -WILL EMPLOYMENT. You will be an employee-at-will, meaning that either
you or the Company may terminate your employment relationship at any time,
without notice, for any reason or no reason, subject to the Company's
obligations set forth in this offer letter.

14. START DATE. Your employment with the Company will commence at a date to be
mutually determined but no later than full-time on Tuesday, February 1, 2000.

15. EXPIRATION. This offer expires January 31, 2000.

16. FEDERAL IMMIGRATION LAW. For purpose of federal immigration law, you will be
required to provide the Company documentary evidence of your identity and
eligibility for employment in the United States. Such documentation must be
provided to us within 3 business days of your commencement date, or our
employment relationship with you may be terminated.

17. ENTIRE AGREEMENT. This Agreement, together with your stock option
agreements, and your Employee NDA, constitutes the entire agreement between the
parties and supersedes all other agreements or understandings.

         Bob, on behalf of the Board, let me indicate how pleased I am to extend
this offer, and how much I look forward to working with you. Please indicate
your acceptance by signing and returning the enclosed copy of this letter.

                                                Sincerely,

                                                ON Technology Corporation


                                                By:
                                                   ---------------------------

                                                Title:
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The forgoing terms and conditions are hereby accepted:

Signed:
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           Robert L. Doretti

Date:
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Indicated Start Date:
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