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                                                                   EXHIBIT 10.13

                                                                      MARIMBA(R)

                                                                   Marimba, Inc.
                                                                440 Clyde Avenue
                                                               Mountain View, CA
                                                                      94034-2232
                                                                 www.marimba.com

                                                                  P 650 930-5282
                                                                  F 650 930-5600

August 9, 2002

Lee Bieber
2961 South Court
Palo Alto, CA  94306

Dear Lee:

         This letter (the "Agreement") is to confirm the agreement between you
and Marimba, Inc. (the "Company") regarding the termination of your employment
with the Company.

           1.   Your employment with the Company will terminate on August 9,
                2002 ("Termination Date"). Through the Termination Date, you
                agree to continue to perform the job duties assigned to you by
                the Company and the Company agrees that it will continue to pay
                you your current base salary and provide you any employee
                benefits that you are otherwise entitled to receive through the
                Termination Date. On the Termination Date, you will be paid for
                any accrued but unused PTO and all of your salary earned but
                unpaid through the Termination Date, less all applicable
                withholdings.

           2.   Although you are not otherwise entitled to receive any severance
                pay from the Company, on the later of: (a) eight days after you
                sign this Agreement or; (b) the Termination Date, the Company
                will pay you a lump sum severance payment of $144,687.50, less
                all applicable withholdings.

           3.   You agree that the only payments and benefits that you are
                entitled to receive from the Company on or following the
                Termination Date are those expressly set forth in this
                Agreement. You acknowledge and agree that this Agreement
                supercedes any other agreement between you and the Company,
                including (but not limited to) your Offer Letter dated September
                30, 1997, the Restricted Stock Agreement and Notice of
                Restricted Stock Award entered into by and between

                                        1

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                you and the Company dated July 24, 2001, the Amendment to the
                Agreements Governing the Restricted Stock Award into by and
                between you and the Company dated June 18, 2002, the Employee
                Incentive Agreement entered into by and between you and the
                Company dated July 24, 2001, and the Stock Option Agreement
                entered into by and between you and the Company dated July 24,
                2002 (collectively, the "Prior Agreements") to the extent that
                such Prior Agreements provide for payments or benefits upon a
                termination of your employment. Any obligation of the Company to
                provide you such payments or benefits under any of the Prior
                Agreements is hereby terminated in its entirety, including, but
                not limited to, any provisions of the Prior Agreements providing
                for accelerated vesting of any Company restricted stock or stock
                options. You expressly waive any right you may have under any of
                the Prior Agreements to accelerated vesting of any Company
                restricted stock you hold on the Termination Date and to
                accelerated vesting or exercisability of any Company stock
                options you hold on the Termination Date.

         4.     The Company will exercise its Right of Repurchase as set forth
                in the Restricted Stock Agreement entered into by and between
                you and the Company dated July 24, 2001, pursuant to which the
                Company will repurchase the shares you purchased pursuant to
                that agreement at the price of $0.0001 per share (the price at
                which you purchased such shares). You agree that the entire
                50,000 shares subject to such Restricted Stock Agreement, and
                any amendment thereto, are unvested and will be repurchased by
                the Company at the total price of five dollars ($5.00). You
                further agree that this Agreement constitutes the written notice
                required for the Company to exercise its Right of Repurchase
                with respect to such shares.

         5.     In consideration for receiving the severance payment described
                in paragraph 2 above, you waive and release and promise never to
                assert any claims or causes of action, whether or not now known,
                against the Company or its predecessors, successors, or past or
                present subsidiaries, officers, directors, agents, employees and
                assigns, with respect to any matter, including, without
                limitation, any matter arising out of or connected with your
                employment with the Company or the termination of that
                employment, including without limitation, claims of wrongful
                discharge, constructive discharge, emotional distress,
                defamation, invasion of privacy, fraud, breach of contract,
                breach of the covenant of good faith and fair dealing, any
                claims of discrimination or harassment based on sex, age, race,
                national origin, disability or on any other basis, under Title
                VII of the Civil Rights Act of 1964, as amended, the California
                Fair Employment and Housing Act, the Age Discrimination in
                Employment Act of 1967, the Older Workers Benefit Protection
                Act, the Americans with Disabilities Act, the California Labor
                Code (including Section 201), and all other laws and regulations
                relating to employment.

         6.     You expressly waive and release any and all rights and benefits
                under Section 1542 of the Civil Code of the State of California
                (or any analogous law of any other state), which reads as
                follows: "A GENERAL RELEASE DOES NOT

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                EXTEND TO CLAIMS WHICH THE CREDITOR DOES NOT KNOW OR SUSPECT TO
                EXIST IN HIS FAVOR AT THE TIME OF EXECUTING THE RELEASE, WHICH,
                IF KNOWN BY HIM, MUST HAVE MATERIALLY AFFECTED HIS SETTLEMENT
                WITH THE DEBTOR." You understand that this Agreement constitutes
                a waiver and release of all claims as set forth herein,
                including any such claims that you may discover in the future
                and any such based on facts you may discover in the future.

         7.     Nothing contained in this letter shall constitute or be treated
                as an admission by you or the Company of liability, of any
                wrongdoing, or of any violation of law.

         8.     At all times in the future, you will remain bound by the
                Company's Proprietary Information and Invention Agreement
                ("PIIA") signed by you on October 20, 1997 a copy of which is
                attached, including but not limited to, your non-solicitation
                obligation as set forth in paragraph 4 of the PIIA.

         9.     You understand and agree that you shall have no further rights
                to vesting of any stock options granted to you by the Company,
                or restricted stock purchased by you from the Company, following
                the Termination Date. You further understand that, except as set
                forth in paragraph 3 of this Agreement, all the terms,
                conditions and limitations applicable to your stock option
                grants shall remain in full force and effect.

         10.    You agree that you will not disclose to others the fact or terms
                of this Agreement, except that you may disclose such information
                to your attorney or accountant in order for such individuals to
                render services to you.

         11.    You agree that you shall not make any negative or disparaging
                remarks about the Company, its officers, employees, directors,
                products, services or business practices.

         12.    You agree that except as expressly provided in this Agreement,
                this Agreement renders null and void any and all prior
                agreements between you and the Company. You and the Company
                agree that this Agreement constitutes the entire agreement
                between you and the Company regarding the subject matter of this
                Agreement, and that this letter agreement may be modified only
                in a written document signed by you and a duly authorized
                officer of the Company.

         13.    This Agreement shall be construed and interpreted in accordance
                with the laws of the State of California.

         14.    You agree that this Agreement may be executed in counterparts,
                each of which shall be an original, but all of which together
                shall constitute one agreement. Execution of a facsimile copy
                shall have the same force and effect as execution of an
                original, and a facsimile signature shall be deemed an original
                and valid signature.

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                15. You have up to twenty-one (21) days after receipt of this
                    Agreement within which to review it, and to discuss it with
                    an attorney of your own choosing, at your expense, regarding
                    whether or not you wish to sign it. Furthermore, you have
                    seven (7) days after you have signed this Agreement during
                    which time you may revoke this Agreement.

                16. If you wish to revoke this Agreement, you may do so by
                    delivering a letter of revocation to me. Because of this
                    revocation period, you understand that this Agreement shall
                    not become effective or enforceable until the eighth day
                    after the date you sign this Agreement.

         Please indicate your agreement with the above terms by signing below.

                                        Sincerely yours,

                                        /s/ Jonathan Schoonmaker
                                        ------------------------
                                        Jonathan Schoonmaker

         My agreement with the above terms is signified by my signature below.
Furthermore, I acknowledge that I have read and understand this Agreement, that
I have been represented by counsel in the review and negotiation of this
Agreement or that I voluntarily declined to seek such counsel, and that I sign
this release of all claims voluntarily, with full appreciation that at no time
in the future may I pursue any of the rights I have waived in this Agreement.

Signed:      /s/ Lee Bieber               Dated: 8/9/02
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             Lee Bieber