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                                                                    EXHIBIT 10.6



                              WITNESS SYSTEMS, INC.
                          EMPLOYEE STOCK PURCHASE PLAN

                                    ARTICLE I
                                 PURPOSE OF PLAN

         Witness Systems, Inc. has adopted this employee stock purchase plan to
encourage the employees of the Company (and its participating affiliated
companies) to acquire a proprietary interest, or to increase their existing
proprietary interest, in the Company. The Board of Directors of the Company
believes that employee ownership of the Company's stock will serve as an
incentive, encouraging employees to continue their employment and to perform
diligently their duties as employees. It is further intended that the Plan
qualify as an "employee stock purchase plan" within the meaning of Code ss.423.

                                   ARTICLE II
                                  DEFINITIONS

         When used in this Plan with initial capital letters, the following
terms shall have the meanings set forth below:

         2.1      Board shall mean the Board of Directors of the Company.

         2.2      Code shall mean the Internal Revenue Code of 1986, as amended.

         2.3      Committee shall mean the group of individuals appointed by the
Board to administer the Plan, pursuant to Section 10.1.

         2.4      Common Stock shall mean the common stock of the Company.

         2.5      Company shall mean Witness Systems, Inc..

         2.6      Effective Date shall mean the day on which the Common Stock is
initially offered for purchase to the public by the Company.

         2.7      Eligible Employee shall mean, with respect to an Offering
Period, an Employee who is not described by the following:

                  (a)      any Employee who is regularly scheduled to work
         (determined as of the Enrollment Date for such Offering Period) 20
         hours or less per week;

                  (b)      any Employee who is regularly scheduled to work
         (determined as of the Enrollment Date for such Offering Period) for not
         more than five (5) months in any calendar year; and

                  (c)      any Employee who, immediately after an option would
         be granted hereunder, would own shares of the Common Stock, or of the
         stock of a parent or subsidiary corporation of the Company, possessing
         5% or more of the total combined voting power or value of all classes
         of such stock. In determining whether an Employee owns 5% of such
         shares, (A) the attribution of ownership rules of Code ss.424(d) shall
         apply, and (B) an Employee shall be deemed to own the shares of stock
         underlying any outstanding option which he has been granted (whether
         under the Plan or any other plan or arrangement).

         2.8      Employee shall mean any individual who is a common-law
employee of any Participating Company. Certain Employees are not eligible to
participate in the Plan, pursuant to Section 3.2 hereof.

         2.9      Enrollment Date shall mean the last business day of the
calendar month immediately preceding each Offering Commencement Date, except
that, with respect to the initial Offering Period, the







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Enrollment Date shall be the last business day of the calendar month immediately
following the calendar month in which the initial registration statement
registering the shares of Common Stock issuable hereunder pursuant to the
Securities Act of 1933, as amended, is declared effective.

         2.10     Fair Market Value shall mean, as of any date, the value of
Common Stock determined as follows:

                  (a)      For purposes of making purchases under the Plan which
         are made on the open market, the Fair Market Value of the Common Stock
         shall be the actual market price on the date and at the time of the
         purchase;

                  (b)      For purposes other than making purchases under the
         Plan, the Fair Market Value of the Common Stock shall be determined as
         follows:

                           (i)      If the Common Stock is listed on any
                  established stock exchange or a national market system,
                  including without limitation the National Market of the
                  National Association of Securities Dealers, Inc. Automated
                  Quotation ("NASDAQ") System, its Fair Market Value per share
                  shall be the closing sale price for the Common Stock (or the
                  mean of the closing bid and asked prices, if no sales were
                  reported), as quoted on such exchange or system on the date of
                  such determination, as reported in The Wall Street Journal or
                  such other source as the Committee deems reliable;

                           (ii)     If the Common Stock is not listed on any
                  established stock exchange or a national market system, its
                  Fair Market Value per share shall be the average of the
                  closing dealer "bid" and "ask" prices of a share of the Common
                  Stock as reflected on the NASDAQ interdealer quotation system
                  of the National Association of Securities Dealers, Inc. on the
                  date of such determination;

                           (iii)    In the absence of an established market for
                  the Common Stock, the Fair Market Value thereof shall be
                  determined in good faith by the Board.

                           (iv)     If, for any reason, the Fair Market Value
                  per share cannot be ascertained or is unavailable for the date
                  in question, the Fair Market Value per share shall be
                  determined as of the nearest preceding date on which such Fair
                  Market Value can be ascertained under the appropriate method
                  indicated above.

                  (c)      Notwithstanding the above provisions, for purposes of
         making purchases under the Plan during the initial Offering Period, the
         Fair Market Value per share of the Common Stock as of the Effective
         Date shall be deemed to be the price per share at which the Common
         Stock is offered to the public by the Company pursuant to the Company's
         initial public offering.

         2.11     Offering Commencement Date shall mean the first day of each
Offering Period.

         2.12     Offering Exercise Date shall mean the last day of each
Offering Period.

         2.13     Offering Period shall mean the period during which each option
granted pursuant to the Plan is in effect. The duration and timing of Offering
Periods may be changed by the Committee pursuant to Section 4.2 of this Plan.

         2.14     Offering Period Pay shall mean, with respect to an Offering
Period, the product of (i) the number of complete payroll periods in such
Offering Period, times (ii) such Employee's Total Pay for the payroll period
which ends on or immediately prior to the Offering Commencement Date of such
Offering Period.





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         2.15     Participating Company shall mean (i) the Company, and (ii) any
"parent corporation" or "subsidiary corporation" (as defined in Code
ss.ss.424(e) and (f)) of the Company which have been designated by the Board and
which have adopted (by formal written resolutions of the board of directors of
such corporation) the Plan for the benefit of its employees.

         2.16     Plan shall mean the Witness Systems, Inc. Employee Stock
Purchase Plan.

         2.17     Total Pay shall mean, with respect to an Employee, all of his
regular straight-time earnings, plus commissions, overtime, shift premium,
incentive compensation, incentive payments, bonuses, and other compensation, all
as reported to the Internal Revenue Service for federal income tax purposes on
Form W-2, plus any before-tax contributions made to plans covered by Code
ss.ss.401(k) and 125.

                                   ARTICLE III
                                   ELIGIBILITY

         3.1      Participation by Eligible Employees. An Eligible Employee of a
Participating Company shall be eligible to participate in the Plan as of the
first day of the Offering Period which next begins following the date of hire of
such Eligible Employee by the Company if the Employee is an Eligible Employee as
of such date.

         3.2      Transfers to/from Eligible Class. An Employee who ceases to be
an Eligible Employee during an Offering Period but who remains an Employee shall
be treated as if he had made an election to modify his payroll deductions to
zero effective for payroll periods ending on or after the date on which such
Employee ceased to be an Eligible Employee. An Employee who becomes an Eligible
Employee during an Offering Period and who was an Employee prior to the date on
which such Employee became an Eligible Employee hereunder shall be entitled to
participate in the Plan as of the first day of the Offering Period which next
begins on or after the date on which such Employee becomes an Eligible Employee
if the Employee is an Eligible Employee as of such date.

                                   ARTICLE IV
                                OFFERING PERIODS

         4.1      Semi-Annual Offering Periods. The Plan shall be implemented by
a continuous series of Offering Periods. The Offering Periods under the Plan
shall be the six-month periods of January 1 through June 30, and July 1 through
December 31, with the initial Offering Period beginning on the Effective Date
and ending on June 30, 2000.

         4.2      Other Offering Periods. Without amendment to the Plan, the
Committee may, in its sole discretion, designate other periods as Offering
Periods. These periods may be more or less frequent and may be in addition to or
in lieu of the semi-annual Offering Periods described in Section 4.1 above.

                                    ARTICLE V
                             ELECTION TO PARTICIPATE

         5.1      Election. Each employee who is eligible to participate in the
Plan may file with the Committee, on or before 5:00 p.m. on any Enrollment Date
(within such time period as provided by the Committee), an election form
authorizing specified regular payroll deductions over the next succeeding
Offering Period; provided, however, with respect to the initial Enrollment Date,
no election shall be valid unless given with a period specified by the Committee
prior to such date. These payroll deductions shall be on an after-tax basis, so
that all applicable federal, state, local and Social Security taxes shall apply.
At the time an Employee files his election form, he shall elect to have payroll
deductions made on each payday during the Offering Period (or, for the initial
Offering Period, during the period beginning immediately following the initial
Enrollment Date and ending on the initial Offering Exercise Date) in an amount
which is not less than 1% nor greater than 15% of such Employee's Total Pay for
each payroll period. No cash contributions or payments may be made by an
Employee to the Plan. Payroll deductions



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for an Employee shall commence on the first payroll period beginning after the
Offering Commencement Date (or, for the initial Offering Period, the Enrollment
Date) and shall end on the last payroll in the Offering Period before the
Offering Exercise Date, to which such authorization is applicable, unless sooner
terminated by the Employee.

         5.2      Deemed Election. An Employee who has entered into a written
agreement with the Company not to be eligible for participation in this Plan
and/or any employee benefit plans of the Company shall, by entering into such
written agreement, automatically be considered to have elected to have none of
his pay deducted under this Plan during any Offering Period which begins while
such written agreement is in effect.

         5.3      Accounts. The Committee shall establish a bookkeeping account
for each Employee in the Plan and shall credit each Employee's payroll
deductions to his account. Any funds actually held in Accounts shall remain part
of the general assets of the Company and may be used by the Company for any
corporate purpose.

         5.4      Withdrawals. By written notice to the Committee during an
Offering Period (on such form or in such manner as the Committee may specify),
but at least thirty (30) days prior to the Offering Exercise Date for such
Offering Period, an Employee may elect to cease his payroll deductions effective
as soon as administratively practicable following receipt of such election, and
the Employee may also elect to withdraw the total amount (but not less than the
total amount) credited to his Account. Any such withdrawn amount shall be paid
to the Employee, in cash or its equivalent, without interest, as promptly as
administratively practicable. An Employee who elects to withdraw the total
amount credited to his Account shall cease participation in the Plan as of the
next following Offering Exercise Date and shall not participate again until the
Offering Commencement Date following such Offering Exercise Date, provided he
files an election form with the Committee on or before the Enrollment Date for
such succeeding Offering Commencement Date.

         5.5      Modifications. An Employee may not elect to modify his payroll
deductions during an Offering Period, except as provided in Section 5.4 above.

         5.6      Leave of Absence. For purposes of participation in the Plan,
an Employee who is on a leave of absence shall be deemed to be an Employee for
the first ninety (90) days of such leave of absence; provided, that as of the
close of business on the ninetieth (90th) day of such leave of absence, the
Employee's employment (solely for purposes of the Plan) shall be deemed to have
terminated unless the Employee shall have returned to his regular employment
prior to the close of business on such ninetieth (90th) day, except as otherwise
required by law. If an Employee's employment is terminated earlier by the
Company, for any reason, his right to participate in the Plan shall terminate
simultaneously.

         5.7      Interest. No interest will accrue or be paid on any payroll
deductions contributed to the Plan or credited to the Account of any Employee.

                                   ARTICLE VI
                               GRANTING OF OPTIONS

         6.1      Number of Option Shares. On each Offering Commencement Date,
each Employee who is eligible to participate in this Plan shall be granted an
option to purchase a maximum number of shares of the Common Stock determined by
dividing 15% of his expected Offering Period Pay by 85% of the Fair Market Value
of one share of the Common Stock on such Offering Commencement Date and rounding
the result down to the nearest whole number.

         6.2      Duration. Each option granted on an Offering Commencement Date
shall terminate on the immediately following Offering Exercise Date, unless
terminated earlier pursuant to the terms of the Plan.






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         6.3      Annual Limit on Options Granted. No option to purchase shares
under the Plan shall be granted to an Employee if such option, when combined
with all other options granted under all of the Code ss. 423 employee stock
purchase plans of the Company, its parents and its subsidiary corporations,
would permit such Employee to purchase shares of the Common Stock with a Fair
Market Value (determined at the time the option is granted) in excess of $25,000
for each calendar year in which the option is outstanding at any time,
determined in accordance with Code ss.423(b)(8).

         6.4      Option Exercise Price. The Option Exercise Price of each share
of the Common Stock shall be the lesser of (i) 85% of the Fair Market Value of
such share on the Offering Commencement Date, or (ii) 85% of the Fair Market
Value of such share on the Offering Exercise Date.

                                   ARTICLE VII
                               EXERCISE OF OPTIONS

         7.1      Automatic Purchase. As of each Offering Exercise Date and
except as provided in Sections 7.2 and 7.3 hereof, the Committee shall purchase,
for each Employee having funds credited to his Account, the number of whole
shares of the Common Stock which is the lesser of (i) the maximum number of such
shares for which such Employee has been granted an option to purchase during
such Offering Period, or (ii) the number of whole shares of the Common Stock
determined by dividing the amount credited to his Account by the Option Exercise
Price. No fractional shares shall be issued, and, except as provided in Sections
7.2 and 7.3 hereof, any amount in an Employee's Account that could have
represented the purchase of such fractional shares, or that exceeds the Option
Exercise Price for the shares of the Common Stock purchased on such Offering
Exercise Date, shall be carried forward in such Employee's Account and shall be
available for purchasing shares of Common Stock in the next succeeding Offering
Period.

         7.2      Maximum Amount of Common Stock Purchased. Notwithstanding any
provisions to the contrary contained herein, no Employee may use the amount
credited to his Account pursuant to the Plan during any calendar year for
purchase of Common Stock exceeding $25,000 in Fair Market Value (determined as
of the Offering Commencement Date). When this amount of Common Stock has been
purchased, any excess amount credited to an Employee's Account (including any
excess resulting from an inability to purchase a whole share) shall be returned
to such Employee, payroll deductions for such Employee shall cease, and such
Employee shall be ineligible to participate in any subsequent Offering Period
occurring during that same calendar year. Such Employee's election automatically
shall become effective on the first Offering Commencement Date of the next
succeeding calendar year, subject to the termination provisions herein. To the
extent that the amount credited to his Account pursuant to the Plan for purchase
of Common Stock during any calendar year is greater than necessary for such
purchase, any excess shall be returned to such Employee as promptly as
administratively practicable.

                                  ARTICLE VIII
                  DELIVERY OF COMMON STOCK; SHAREHOLDER RIGHTS

         As soon as practicable after each Offering Exercise Date, the Company
shall issue and deliver to each Employee certificates representing the shares of
the Common Stock, if any, purchased for such Employee, together with any cash to
which he may be entitled hereunder. Upon issuance of such certificates (but not
prior thereto), the Employee shall have all of the rights and privileges of a
shareholder of the Company with respect to such shares. Common Stock to be
delivered to an Employee pursuant to the Plan shall be registered in the name of
the Employee.

                                   ARTICLE IX
                           STOCK RESERVED FOR OPTIONS

         9.1      Shares Reserved for Use By Plan. The Company shall reserve a
total of five hundred fifty thousand (550,000) shares of the Common Stock for
issuance and purchase by Employees under the Plan; provided, however, this total
number of shares of Common Stock that may be issued pursuant to this Plan



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shall be automatically increased on the last trading day of the final month of
each calendar year of the Company, beginning with the calendar year ending
December 31, 2000, by (1) a number of Shares equal to 2% of the number of shares
of Common Stock outstanding on the last trading day of the month preceding the
final month of each such calendar year or (2) such lesser amount as may be
determined by the Board in its sole discretion, but in no event shall any such
annual increase exceed five hundred thousand (500,000) Shares (as adjusted for
any change contemplated in Article XII hereof). The number of shares of the
Common Stock reserved for the Plan may be adjusted as provided in Article XII.
The shares of the Common Stock reserved for the Plan may be shares now or
hereafter authorized but unissued or may be shares of treasury stock.

         9.2      Shares Subject to Unexercised Options. If and to the extent
that any right to purchase reserved shares of the Common Stock shall not be
exercised by the Employee who is the holder of such right, or if such right
shall terminate as provided herein, then the shares subject to such right to
purchase (i) shall again become available for purposes of the Plan, unless the
Plan shall have been terminated, and (ii) shall not be deemed to increase the
number of shares of the Common Stock reserved for purposes of the Plan.

                                    ARTICLE X
                             ADMINISTRATION OF PLAN

         10.1     Appointment of Committee. The Plan shall be administered by a
committee, which shall consist of those persons so designated by the Board. The
Board from time to time may remove members from, or add members to, the
Committee. Vacancies on the Committee shall be filled by the Board.

         10.2     Meetings. The Committee shall select one of its members as
Chairman and shall hold meetings at such times and places as the Chairman shall
determine. A majority of the members of the Committee shall constitute a quorum,
and the Committee may act by vote of a majority of its members at a meeting at
which a quorum is present, or without a meeting by a written consent to their
action signed by all members of the Committee.

         10.3     Authority. The Committee may request advice or assistance or
employ such other persons as are necessary for proper administration of the
Plan. Subject to the express provisions of the Plan, the Committee shall have
authority to interpret the Plan, to prescribe rules and regulations for
administering the Plan, and to make all other determinations necessary or
advisable in administering the Plan; all of such determinations shall be final
and binding upon all persons, unless otherwise determined by the Board. Without
amendment to the Plan, the Committee shall be authorized to:

                  (a)      limit the frequency and/or number of changes in the
         payroll deduction amounts withheld during an Offering Period;

                  (b)      permit payroll withholding in excess of the amount
         designated by an Employee in order to adjust for delays or mistakes in
         the Company's processing of properly completed election forms;

                  (c)      establish reasonable waiting and adjustment periods
         and/or accounting and crediting procedures to ensure that amounts
         applied toward the purchase of Company Stock for each Employee properly
         correspond with amounts withheld from the Employee's paychecks; and

                  (d)      establish such other limitations or procedures as it
         may determine, in its sole discretion, advisable which are consistent
         with the terms of the Plan.





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                                   ARTICLE XI
                             RIGHTS NOT TRANSFERABLE

         Rights under the Plan are not transferable by an Employee other than by
will or the laws of descent and distribution and are exercisable during his
lifetime only by him.

                                   ARTICLE XII
                          ADJUSTMENT IN CASE OF CHANGES
                          AFFECTING THE COMPANY'S STOCK

         12.1     General Rule. In the event of a split, subdivision or
consolidation of outstanding shares of the Common Stock, or in the event of any
"corporate transaction", as defined in Treas. Reg. ss.1.425-1(a)(1)(ii), other
than a transaction described in Section 12.2 hereof, the number of shares of the
Common Stock reserved or authorized to be reserved under the Plan and the number
and price of such shares subject to purchase pursuant to options outstanding
hereunder, in the sole discretion of the Committee, may be adjusted in such
manner as may be deemed necessary or equitable by the Committee to give proper
effect to such event. If any adjustment hereunder would create a fractional
share or a right to acquire a fractional share, such fractional share shall be
disregarded, and the number of shares available under the Plan or the number of
shares to which any Employee shall be entitled will be the next lower number of
shares, rounding all fractions downward. Notwithstanding anything herein to the
contrary, all adjustments to the shares of the Common Stock shall be made in
such a manner as to comply with the requirements of Code ss.424 and to preserve
the options' status under Code ss.423.

         12.2     Dissolution or Certain Mergers. A dissolution or liquidation
of the Company or a merger or consolidation in which the Company is not the
surviving corporation, shall cause each outstanding option to terminate;
provided, that each Employee shall, in such event, have paid to him in cash the
amount credited to his Account at that time prior to such dissolution or
liquidation, or merger or consolidation in which the Company is not the
surviving corporation.

         12.3     Rights of Employees. Except as hereinabove expressly provided,
no Employee shall have any rights by reason of any subdivision or consolidation
of shares of stock of any class or any other increase or decrease in the number
of shares of stock of any class by reason of any dissolution, liquidation,
merger or consolidation or spin-off of the assets or stock of another
corporation; and any issue by the Company of shares of stock of any class, or
securities convertible into shares of stock of any class, shall not affect, and
no adjustment by reason thereof shall be made with respect to, the number or
price of shares of the Common Stock subject to the option. The grant of an
option pursuant to the Plan shall not affect in any way the right or power of
the Company to make adjustments, reclassifications, reorganizations or changes
of its capital or business structure or to merge or to consolidate or to
dissolve, liquidate or sell, or transfer all or any part of its business or
assets.

                                  ARTICLE XIII
                 TERMINATION OF EMPLOYMENT OR DEATH OF EMPLOYEE

         13.1     Termination of Employment. In the event of an Employee's
termination of employment (for any reason other than death) during a Offering
Period (other than the last day of such Offering Period), any option granted to
him under the Plan shall terminate immediately upon the date his employment
ends, and the amount credited to his Account shall be refunded to him in cash as
soon as practicable after the earlier of (1) the Offering Exercise Date of such
Offering Period, or (2) the payroll period next following his termination of
employment.

         13.2     Death. In the event of an Employee's death during a Offering
Period (other than the last day of such Offering Period), any option granted to
him under the Plan for such Offering Period shall terminate immediately upon the
date of his death, and the amount credited to his Account for such Offering
Period shall be paid in cash to the person(s) designated as his beneficiary as
soon as practicable






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after the earlier of (1) the Offering Exercise Date of such Offering Period, or
(2) the payroll period next following his termination of employment. Also, in
the event any shares of the Common Stock and/or any cash is payable to the
deceased Employee with respect to an Offering Period ending on or before his
date of death, such shares and/or cash shall be paid to the person(s) designated
as his beneficiary.

         13.3     Beneficiary. An Employee may file with the Committee a written
designation of a beneficiary who is to receive any Common Stock or cash pursuant
to the Plan in the event of the death of such Employee prior to delivery to him
of such Common Stock or cash. Such designation of beneficiary may be changed by
the Employee, and upon receipt by the Committee of proof of the identity at the
Employee's death of a beneficiary validly designated by him pursuant to the
Plan, the Company shall deliver such Common Stock or cash to such beneficiary.
In the absence of a validly-designated beneficiary who is living at the time of
such Employee's death, the Company shall deliver such Common Stock or cash to
the estate of such Employee. No designated beneficiary shall, prior to the death
of the Employee by whom he has been designated, acquire any interest in the
Common Stock or cash which may be credited to the account of the Employee under
the Plan. Any decision by the Committee as to the person or persons to whom to
distribute the Common Stock or cash shall be binding and shall not create any
liability whatsoever on the part of the Company or the Committee or its members.

                                   ARTICLE XIV
                      AMENDMENT AND TERMINATION OF THE PLAN

         14.1     Amendment. The Board may amend the Plan in any respect;
provided, any amendment (i) increasing the number of shares of the Common Stock
reserved under the Plan, (ii) changing the designated class of employees
eligible to participate in the Plan, or (iii) materially increasing the benefits
accruing to Employees under the Plan, must be approved within 12 months of the
adoption of such an amendment by the holders of a majority of the voting power
of the outstanding shares of the Common Stock.

         14.2     Termination. The Plan and all rights of Employees hereunder
shall terminate:

                  (a) as of the Offering Exercise Date that Employees become
         entitled to purchase a number of shares of the Common Stock that
         substantially exhausts the number of such shares available for issuance
         under the Plan, to such an extent that the Board and the Committee
         determine that no subsequent options are practicable; or

                  (b) in the sole discretion of the Board, as of the end of any
         Offering Period with respect to future Offering Periods.

         14.3     Compliance. To the extent necessary for compliance with Code
ss.423 (or any successor provisions), the Company shall obtain shareholder
approval in such a manner and to such a degree as may be required for any
amendment to or termination of the Plan.

                                   ARTICLE XV
                                     NOTICES

         All notices or other communications by an Employee to the Committee
pursuant to or in connection with the Plan shall be deemed to have been duly
given when received in the form specified by the Committee at the location, or
by the person, designated by the Committee for the receipt thereof.







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                                   ARTICLE XVI
                          INDEMNIFICATION OF COMMITTEE

         In addition to such other rights of indemnification as they may have as
directors, the members of the Committee shall be indemnified by the Company
against reasonable expenses (including, without limitation, attorneys' fees)
actually and necessarily incurred in connection with the defense of any action,
suit or proceeding, or in connection with any appeal, to which they or any of
them may be a party by reason of any action taken or failure to act under or in
connection with the Plan or any option granted hereunder, and against all
amounts paid by them in settlement thereof (provided such settlement is approved
to the extent required by and in the manner provided by the Bylaws of the
Company relating to indemnification of directors) or paid by them in
satisfaction of a judgment in any such action, suit or proceeding, except in
relation to matters as to which it shall be adjudged in such action, suit or
proceeding that such Committee member or members did not act in good faith and
in a manner he reasonably believed to be in or not opposed to the best interests
of the Company.

                                  ARTICLE XVII
                            WITHHOLDING REQUIREMENTS

         At the time the option is exercised, in whole or in part, or at the
time some or all of the Common Stock issued under the Plan is disposed of, the
Employee must make adequate provision for the Company's federal, state, or other
tax withholding obligations, if any, which arise upon the exercise of the option
or the disposition of the Common Stock. At any time, the Company may, but will
not be obligated to, withhold from the Employee's compensation the amount
necessary for the Company to meet applicable withholding obligations, including
any withholding required to make available to the Company any tax deductions or
benefits attributable to sale or early disposition of Common Stock by the
Employee.

                                  ARTICLE XVIII
                              CONSTRUCTION OF PLAN

         For purposes of the Plan, masculine, feminine, neuter, singular or
plural pronouns shall be deemed to refer to such person, persons or entity as
may be appropriate in the context.

                                   ARTICLE XIX
                                EXPENSES OF PLAN

         The Company shall pay all operational expenses of the Plan, including,
without limitation, all brokerage commissions due and payable for the purchase
and sale of Common Stock.

                                   ARTICLE XX
                                   COMPLIANCE

         The Plan is intended to comply with the requirements of Code ss.423
(and any of its successor provisions). Pursuant to Code ss.423, an Employee may
be eligible for certain favorable tax treatment with regard to Common Stock
purchased under the Plan, if no disposition of the Common Stock is made by such
Employee within 2 years after the date of the granting of the option to him
under the Plan nor within 1 year after the transfer of the Common Stock to him.

                                   ARTICLE XXI
                        EMPLOYEE STATEMENTS AND REPORTING

         On or before January 31 of each calendar year, the Committee shall
provide a statement to each Employee who exercised an option under the Plan
during the previous calendar year. The Employee's statement shall contain the
following information: the name, address and employer identification number of
the Company, the date the Common Stock was transferred to the Employee, the
number of shares which were transferred to the Employee, and the type of option
under which the transferred shares were







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acquired. In addition, pursuant to Code ss.6039, the Committee shall make any
and all filings necessary to the Internal Revenue Service with regard to options
granted and exercised under the Plan.

                                  ARTICLE XXII
                             EFFECTIVE DATE OF PLAN

         The Plan shall become effective as of the Effective Date; provided,
within 12 months of the adoption of the Plan by the Board, the Plan is approved
by the holders of a majority of the voting power of the outstanding shares of
the Common Stock. If the Plan is not so approved, the Plan shall not become
effective and any prior grant of options hereunder shall be null and void ab
initio.

         IN WITNESS WHEREOF, the Plan is hereby executed by a duly authorized
officer of the Company, on this 3rd day of December, 1999.



                                        COMPANY:

                                        WITNESS SYSTEMS, INC.

                                        By:  /s/ David B. Gould
                                           -------------------------------------

                                        Title:   President
                                              ----------------------------------




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