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                                                                    EXHIBIT 10.1

                          CONCORD COMMUNICATIONS, INC.
                                1997 STOCK PLAN
                (AS AMENDED ON MARCH 12, 1998 AND MARCH 1, 1999)

     1.  PURPOSE; TERMINATION OF PRIOR PLAN.  The purpose of the 1997 Stock Plan
(the "Plan") is to encourage key employees of Concord Communications, Inc. (the
"Company") and of any present or future parent or subsidiary of the Company
(collectively, "Related Corporations") and other individuals who render services
to the Company or a Related Corporation, by providing opportunities to
participate in the ownership of the Company and its future growth through (a)
the grant of options which qualify as "incentive stock options" ("ISOs") under
Section 422(b) of the Internal Revenue Code of 1986, as amended (the "Code");
(b) the grant of options which do not qualify as ISOs ("Non-Qualified Options");
(c) awards of stock in the Company ("Awards"); and (d) opportunities to make
direct purchases of stock in the Company ("Purchases"). Both ISOs and
Non-Qualified Options are referred to hereafter individually as an "Option" and
collectively as "Options." Options, Awards and authorizations to make Purchases
are referred to hereafter collectively as "Stock Rights." As used herein, the
terms "parent" and "subsidiary" mean "parent corporation" and "subsidiary
corporation," respectively, as those terms are defined in Section 424 of the
Code. The Company's 1995 Stock Plan (the "1995 Stock Plan") is terminated
effective as of October 16, 1997 and henceforth, the Company shall make no
grants under the 1995 Stock Plan. The 1995 Stock Plan shall, however, continue
to govern all options, awards and other grants granted and outstanding under the
1995 Stock Plan.

     2.  ADMINISTRATION OF THE PLAN.

          A.  BOARD OR COMMITTEE ADMINISTRATION.  The Plan shall be administered
     by the Board of Directors of the Company (the "Board") or, subject to
     paragraph 2(D) (relating to compliance with Section 162(m) of the Code), by
     a committee appointed by the Board of two or more of its members (the
     "Committee"). Hereinafter, all references in this Plan to the "Committee"
     shall mean the Board if no Committee has been appointed. Subject to
     ratification of the grant or authorization of each Stock Right by the Board
     (if so required by applicable state law), and subject to the terms of the
     Plan, the Committee shall have the authority to (i) determine to whom (from
     among the class of employees eligible under paragraph 3 to receive ISOs)
     ISOs shall be granted, and to whom (from among the class of individuals and
     entities eligible under paragraph 3 to receive Non-Qualified Options and
     Awards and to make Purchases) Non-Qualified Options, Awards and
     authorizations to make Purchases may be granted; (ii) determine the time or
     times at which Options or Awards shall be granted or Purchases made; (iii)
     determine the purchase price of shares subject to each Option or Purchase,
     which prices shall not be less than the minimum price specified in
     paragraph 6; (iv) determine whether each Option granted shall be an ISO or
     a Non-Qualified Option; (v) determine (subject to paragraph 7) the time or
     times when each Option shall become exercisable and the duration of the
     exercise period; (vi) determine whether restrictions such as repurchase
     options are to be imposed on shares subject to Options, Awards and
     Purchases and the nature of such restrictions, if any; and (vii) interpret
     the Plan and prescribe and rescind rules and regulations relating to it. If
     the Committee determines to issue a Non-Qualified Option, it shall take
     whatever actions it deems necessary, under Section 422 of the Code and the
     regulations promulgated thereunder, to ensure that such Option is not
     treated as an ISO. The interpretation and construction by the Committee of
     any provisions of the Plan or of any Stock Right granted under it shall be
     final unless otherwise determined by the Board. The Committee may from time
     to time adopt such rules and regulations for carrying out the Plan as it
     may deem best. No member of the Board or of the

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     Committee shall be liable for any action or determination made in good
     faith with respect to the Plan or any Stock Right granted under it.

          B.  COMMITTEE ACTIONS.  The Committee may select one of its members as
     its chairman, and shall hold meetings at such time and places as it may
     determine. A majority of the Committee shall constitute a quorum and acts
     of a majority of the members of the Committee at a meeting at which a
     quorum is present, or acts reduced to or approved in writing by all the
     members of the Committee (if consistent with applicable state law), shall
     be the valid acts of the Committee. From time to time the Board may
     increase the size of the Committee and appoint additional members thereof,
     remove members (with or without cause) and appoint new members in
     substitution therefor, fill vacancies however caused, or remove all members
     of the Committee and thereafter directly administer the Plan.

          C.  GRANT OF STOCK RIGHTS TO BOARD MEMBERS.  Notwithstanding the
     provisions of paragraph 2.A., no Stock Rights shall be granted to any
     person who is, at the time of the proposed grant, a member of the Board
     unless such grant is approved by a majority vote of the disinterested
     members of the Board. All grants of Stock Rights to members of the Board
     shall in all respects be made in accordance with the provisions of this
     Plan applicable to other eligible persons. Members of the Board who either
     (i) are eligible to receive grants of Stock Rights pursuant to the Plan or
     (ii) have been granted Stock Rights may vote on any matters affecting the
     administration of the Plan or the grant of any Stock Rights pursuant to the
     Plan, except that no such member shall act upon the granting to himself or
     herself of Stock Rights, but any such member may be counted in determining
     the existence of a quorum at any meeting of the Board during which action
     is taken with respect to the granting to such member of Stock Rights.
     Notwithstanding any other provision of this paragraph 2, in the event the
     Company registers any class of any equity security pursuant to Section 12
     of the Securities Exchange Act of 1934, as amended (the "Exchange Act"),
     any grants to members of the Board of Options made at any time from the
     effective date of such registration until six months after the termination
     of such registration shall be made only by the Board; provided, however,
     that if a majority of the Board is eligible to participate in the Plan or
     in any other stock option or other stock plan of the Company or any of its
     affiliates, or has been so eligible at any time within the preceding year,
     any grant to directors of Options must be made by, or only in accordance
     with the recommendation of, a Committee consisting of three or more
     persons, who may but need not be members of the Board or employees of the
     Company, appointed by the Board but having full authority to act in the
     matter, none of whom is eligible to participate in this Plan or any other
     stock option or other stock plan of the Company or any of its affiliates,
     or has been eligible at any time within the preceding year. The
     requirements imposed by the preceding sentence shall also apply with
     respect to grants to officers who are not also members of the Board. Once
     appointed, the Committee shall continue to serve until otherwise directed
     by the Board.

          D.  PERFORMANCE-BASED COMPENSATION.  The Board, in its discretion, may
     take such action as may be necessary to ensure that Stock Rights granted
     under the Plan qualify as "qualified performance-based compensation" within
     the meaning of Section 162(m) of the Code and applicable regulations
     promulgated thereunder ("Performance-Based Compensation"). Such action may
     include, in the Board's discretion, some or all of the following (i) if the
     Board determines that Stock Rights granted under the Plan generally shall
     constitute Performance-Based Compensation, the Plan shall be administered,
     to the extent required for such Stock Rights to constitute
     Performance-Based Compensation, by a Committee consisting solely of two or
     more "outside directors" (as defined in applicable regulations promulgated
     under Section 162(m) of the Code), (ii) if any Non-Qualified Options with
     an exercise price less than the fair market value per share of Common Stock
     are granted under the Plan and the Board determines that such Options
     should constitute Performance-Based Compensation, such options shall be
     made exercisable only upon the attainment of a pre-established, objective
     performance goal established by the

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     Committee, and such grant shall be submitted for, and shall be contingent
     upon shareholder approval and (iii) Stock Rights granted under the Plan may
     be subject to such other terms and conditions as are necessary for
     compensation recognized in connection with the exercise or disposition of
     such Stock Right or the disposition of Common Stock acquired pursuant to
     such Stock Right, to constitute Performance-Based Compensation.

     3.  ELIGIBLE EMPLOYEES AND OTHERS.  ISOs may be granted only to employees
of the Company or any Related Corporation. Non-Qualified Options, Awards and
authorizations to make Purchases may be granted to any employee, officer or
director (whether or not also an employee) or consultant of the Company or any
Related Corporation. The Committee may take into consideration a recipient's
individual circumstances in determining whether to grant a Stock Right. The
granting of any Stock Right to any individual or entity shall neither entitle
that individual or entity to, nor disqualify such individual or entity from,
participation in any other grant of Stock Rights.

     4.  STOCK.  The stock subject to Stock Rights shall be authorized but
unissued shares of Common Stock of the Company, par value $.01 per share (the
"Common Stock"), or shares of Common Stock reacquired by the Company in any
manner. The aggregate number of shares which may be issued pursuant to the Plan
is 2,500,000, subject to adjustment as provided in paragraph 13. If any Option
granted under the Plan shall expire or terminate for any reason without having
been exercised in full or shall cease for any reason to be exercisable in whole
or in part or shall be repurchased by the Company, the unpurchased shares of
Common Stock subject to such Option shall again be available for grants of Stock
Rights under the Plan.

     No employee of the Company or any Related Corporation may be granted
Options to acquire, in the aggregate, more than 70% of the aggregate number of
shares of Common Stock which may be issued pursuant to the Plan during any
fiscal year of the Company. If any Option granted under the Plan shall expire or
terminate for any reason without having been exercised in full or shall cease
for any reason to be exercisable in whole or in part or shall be repurchased by
the Company, the shares subject to such Option shall be included in the
determination of the aggregate number of shares of Common Stock deemed to have
been granted to such employee under the Plan.

     5.  GRANTING OF STOCK RIGHTS.  Stock Rights may be granted under the Plan
at any time on or after October 16, 1997 and prior to October 15, 2007. The date
of grant of a Stock Right under the Plan will be the date specified by the
Committee at the time it grants the Stock Right; provided, however, that such
date shall not be prior to the date on which the Committee acts to approve the
grant.

     6.  MINIMUM OPTION PRICE; ISO LIMITATIONS.

          A.  PRICE FOR NON-QUALIFIED OPTIONS, AWARDS AND PURCHASES.  Subject to
     paragraph 2(D) (relating to compliance with Section 162(m) of the Code),
     the exercise price per share specified in the agreement relating to each
     Non-Qualified Option granted, and the purchase price per share of stock
     granted in any Award or authorized as a Purchase, under the Plan may be
     less than the fair market value of the Common Stock of the Company on the
     date of grant; provided that, in no event shall such exercise price or such
     purchase price be less than the lesser of (i) the book value per share of
     Common Stock as of the end of the fiscal year of the Company immediately
     preceding the date of such grant, or (ii) 50 percent of the fair market
     value per share of Common Stock on the date of such grant.

          B.  PRICE FOR ISOS.  The exercise price per share specified in the
     agreement relating to each ISO granted under the Plan shall not be less
     than the fair market value per share of Common Stock on the date of such
     grant. In the case of an ISO to be granted to an employee owning stock
     possessing more than ten percent (10%) of the total combined voting power
     of all classes of stock of the Company or any Related Corporation, the
     price per share specified in the agreement relating to such ISO shall not
     be less

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     than one hundred ten percent (110%) of the fair market value per share of
     Common Stock on the date of grant. For purposes of determining stock
     ownership under this paragraph, the rules of Section 424(d) of the Code
     shall apply.

          C.  $100,000 ANNUAL LIMITATION ON ISO VESTING.  Each eligible employee
     may be granted Options treated as ISOs only to the extent that, in the
     aggregate under this Plan and all incentive stock option plans of the
     Company and any Related Corporation, ISOs do not become exercisable for the
     first time by such employee during any calendar year with respect to stock
     having a fair market value (determined at the time the ISOs were granted)
     in excess of $100,000. The Company intends to designate any Options granted
     in excess of such limitation as Non-Qualified Options, and the Company
     shall issue separate certificates to the optionee with respect to Options
     that are Non-Qualified Options and Options that are ISOs.

          D.  DETERMINATION OF FAIR MARKET VALUE.  If, at the time an Option is
     granted under the Plan, the Company's Common Stock is publicly traded,
     "fair market value" shall be determined as of the date of grant or, if the
     prices or quotes discussed in this sentence are unavailable for such date,
     the last business day for which such prices or quotes are available prior
     to the date of grant and shall mean (i) the average (on that date) of the
     high and low prices of the Common Stock on the principal national
     securities exchange on which the Common Stock is traded, if the Common
     Stock is then traded on a national securities exchange; or (ii) the last
     reported sale price (on that date) of the Common Stock on the Nasdaq
     National Market, if the Common Stock is not then traded on a national
     securities exchange; or (iii) the closing bid price (or average of bid
     prices) last quoted (on that date) by an established quotation service for
     over-the-counter securities, if the Common Stock is not reported on the
     Nasdaq National Market. If the Common Stock is not publicly traded at the
     time an Option is granted under the Plan, "fair market value" shall mean
     the fair value of the Common Stock as determined by the Committee after
     taking into consideration all factors which it deems appropriate,
     including, without limitation, recent sale and offer prices of the Common
     Stock in private transactions negotiated at arm's length.

     7.  OPTION DURATION.  Subject to earlier termination as provided in
paragraphs 9 and 10 or in the agreement relating to such Option, each Option
shall expire on the date specified by the Committee, but not more than (i) ten
years from the date of grant in the case of Options generally and (ii) five
years from the date of grant in the case of ISOs granted to an employee owning
stock possessing more than ten percent (10%) of the total combined voting power
of all classes of stock of the Company or any Related Corporation, as determined
under paragraph 6(B). Subject to earlier termination as provided in paragraphs 9
and 10, the term of each ISO shall be the term set forth in the original
instrument granting such ISO, except with respect to any part of such ISO that
is converted into a Non-Qualified Option pursuant to paragraph 16.

     8.  EXERCISE OF OPTION.  Subject to the provisions of paragraphs 9 through
12, each Option granted under the Plan shall be exercisable as follows:

          A.  VESTING.  The Option shall either be fully exercisable on the date
     of grant or shall become exercisable thereafter in such installments as the
     Committee may specify.

          B.  FULL VESTING OF INSTALLMENTS.  Once an installment becomes
     exercisable, it shall remain exercisable until expiration or termination of
     the Option, unless otherwise specified by the Committee.

          C.  PARTIAL EXERCISE.  Each Option or installment may be exercised at
     any time or from time to time, in whole or in part, for up to the total
     number of shares with respect to which it is then exercisable.

          D.  ACCELERATION OF VESTING.  The Committee shall have the right to
     accelerate the date that any installment of any Option becomes exercisable;
     provided that the Committee shall not, without the consent of an optionee,
     accelerate the permitted exercise date of any installment of any Option
     granted to
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     any employee as an ISO (and not previously converted into a Non-Qualified
     Option pursuant to paragraph 16) if such acceleration would violate the
     annual vesting limitation contained in Section 422(d) of the Code, as
     described in paragraph 6(C).

     9.  TERMINATION OF EMPLOYMENT.  Unless otherwise specified in the agreement
relating to such ISO, if an ISO optionee ceases to be employed by the Company
and all Related Corporations other than by reason of death or disability as
defined in paragraph 10, no further installments of his or her ISOs shall become
exercisable, and his or her ISOs shall terminate after the passage of 60 days
from the date of termination of his or her employment, but in no event later
than on the specified expiration dates of such ISOs, except to the extent that
such ISOs (or unexercised installments thereof) have been converted into
Non-Qualified Options pursuant to paragraph 16. For purposes of this paragraph
9, a leave of absence with the written approval of the Committee shall not be
considered an interruption of employment under the Plan, provided that such
written approval contractually obligates the Company or any Related Corporation
to continue the employment of the employee after the approved period of absence.
Employment shall also be considered as continuing uninterrupted during any other
bona fide leave of absence (such as those attributable to illness, military
obligations or governmental service) provided that the period of such leave does
not exceed 90 days or, if longer, any period during which such optionee's right
to reemployment is guaranteed by statute or by contract. A bona fide leave of
absence with the written approval of the Committee shall not be considered an
interruption of employment under this paragraph 9, provided that such written
approval contractually obligates the Company or any Related Corporation to
continue the employment of the optionee after the approved period of absence.
ISOs granted under the Plan shall not be affected by any change of employment
within or among the Company and Related Corporations, so long as the optionee
continues to be an employee of the Company or any Related Corporation. Nothing
in the Plan shall be deemed to give any grantee of any Stock Right the right to
be retained in employment or other service by the Company or any Related
Corporation for any period of time.

     10.  DEATH; DISABILITY.

          A.  DEATH.  If an ISO optionee ceases to be employed by the Company
     and all Related Corporations by reason of his or her death, any ISO owned
     by such optionee may be exercised, to the extent otherwise exercisable on
     the date of death, by the estate, personal representative or beneficiary
     who has acquired the ISO by will or by the laws of descent and
     distribution, at any time prior to the earlier of (i) the specified
     expiration date of the ISO or (ii) 180 days from the date of the optionee's
     death.

          B.  DISABILITY.  If an ISO optionee ceases to be employed by the
     Company and all Related Corporations by reason of his or her disability,
     such optionee shall have the right to exercise any ISO held by him or her
     on the date of termination of employment, for the number of shares for
     which he or she could have exercised it on that date, at any time prior to
     the earlier of (i) the specified expiration date of the ISO or (ii) 180
     days from the date of the termination of the optionee's employment. For the
     purposes of the Plan, the term "disability" shall mean "permanent and total
     disability" as defined in Section 22(e)(3) of the Code or any successor
     statute.

     11.  ASSIGNABILITY.  No ISO shall be assignable or transferable by the
optionee except by will or by the laws of descent and distribution, and during
the lifetime of the optionee shall be exercisable only by such optionee. Stock
Rights other than ISOs shall be transferable to the extent set forth in the
agreement relating to such Stock Right.

     12.  TERMS AND CONDITIONS OF OPTIONS.  Options shall be evidenced by
instruments (which need not be identical) in such forms as the Committee may
from time to time approve. Such instruments shall conform to the terms and
conditions set forth in paragraphs 6 through 11 hereof and may contain such
other provisions as the Committee deems advisable which are not inconsistent
with the Plan, including restrictions applicable to

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shares of Common Stock issuable upon exercise of Options. The Committee may
specify that any Non-Qualified Option shall be subject to the restrictions set
forth herein with respect to ISOs, or to such other termination and cancellation
provisions as the Committee may determine. The Committee may from time to time
confer authority and responsibility on one or more of its own members and/or one
or more officers of the Company to execute and deliver such instruments. The
proper officers of the Company are authorized and directed to take any and all
action necessary or advisable from time to time to carry out the terms of such
instruments.

     13.  ADJUSTMENTS.  Upon the occurrence of any of the following events, an
optionee's rights with respect to Options granted to such optionee hereunder
shall be adjusted as hereinafter provided, unless otherwise specifically
provided in the written agreement between the optionee and the Company relating
to such Option:

          A.  STOCK DIVIDENDS AND STOCK SPLITS.  If the shares of Common Stock
     shall be subdivided or combined into a greater or smaller number of shares
     or if the Company shall issue any shares of Common Stock as a stock
     dividend on its outstanding Common Stock, the number of shares of Common
     Stock deliverable upon the exercise of Options shall be appropriately
     increased or decreased proportionately, and appropriate adjustments shall
     be made in the purchase price per share to reflect such subdivision,
     combination or stock dividend.

          B.  CONSOLIDATIONS OR MERGERS.  If the Company is to be consolidated
     with or acquired by another entity in a merger or other reorganization in
     which the holders of the outstanding voting stock of the Company
     immediately preceding the consummation of such event, shall, immediately
     following such event, hold, as a group, less than a majority of the voting
     securities of the surviving or successor entity, or in the event of a sale
     of all or substantially all of the Company's assets or otherwise (each, an
     "Acquisition"), the Committee may take one or more of the following
     actions: (i) provide for the acceleration and/or termination of any time
     period relating to the exercise of the Options, (ii) provide for the
     purchase of the Options, upon the optionee's request, for the amount in
     cash that could have been received upon the exercise of the Options and
     sale of the shares obtained thereby, (iii) adjust the terms of the Options
     in a manner determined by the Committee, (iv) cause the Options to be
     assumed, or new rights substituted therefor, by another entity or (v) make
     such other provision as the Committee may consider equitable and in the
     best interests of the Company.

          C.  RECAPITALIZATION OR REORGANIZATION.  In the event of a
     recapitalization or reorganization of the Company (other than a transaction
     described in subparagraph B above) pursuant to which securities of the
     Company or of another corporation are issued with respect to the
     outstanding shares of Common Stock, an optionee upon exercising an Option
     shall be entitled to receive for the purchase price paid upon such exercise
     the securities he or she would have received if he or she had exercised
     such Option prior to such recapitalization or reorganization.

          D.  MODIFICATION OF ISOS.  Notwithstanding the foregoing, any
     adjustments made pursuant to subparagraphs A, B or C with respect to ISOs
     shall be made only after the Committee, after consulting with counsel for
     the Company, determines whether such adjustments would constitute a
     "modification" of such ISOs (as that term is defined in Section 424 of the
     Code) or would cause any adverse tax consequences for the holders of such
     ISOs. If the Committee determines that such adjustments made with respect
     to ISOs would constitute a modification of such ISOs or would cause adverse
     tax consequences to the holders, it may refrain from making such
     adjustments.

          E.  RESTRICTED SECURITIES.  If any person or entity owning restricted
     Common Stock obtained by exercise of an Option made hereunder receives new
     or additional or different shares or securities ("New Securities") in
     connection with a transaction described in subparagraphs A, B or C above,
     as a result of owning such restricted Common Stock, such New Securities
     shall be subject to all of the conditions and

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     restrictions applicable to the restricted Common Stock with respect to
     which such New Securities were issued.

          F.  ISSUANCES OF SECURITIES.  Except as expressly provided herein, no
     issuance by the Company of shares of stock of any class, or securities
     convertible into shares of stock of any class, shall affect, and no
     adjustment by reason thereof shall be made with respect to, the number or
     price of shares subject to Options. No adjustments shall be made for
     dividends paid in cash or in property other than securities of the Company.

          G.  FRACTIONAL SHARES.  No fractional shares shall be issued under the
     Plan. Any fractional shares which, but for this subparagraph G, would have
     been issued to an optionee pursuant to an Option, shall be deemed to have
     been issued and immediately sold to the Company for their fair market
     value, and the optionee shall receive from the Company cash in lieu of such
     fractional shares.

          H.  ADJUSTMENTS.  Upon the happening of any of the events described in
     subparagraphs A, B or C above, the class and aggregate number of shares set
     forth in paragraph 4 hereof that are subject to Stock Rights which
     previously have been or subsequently may be granted under the Plan shall
     also be appropriately adjusted to reflect the events described in such
     subparagraphs. The Committee shall determine the specific adjustments to be
     made under this paragraph 13 and, subject to paragraph 2, its determination
     shall be conclusive.

     14.  MEANS OF EXERCISING OPTIONS.  An Option (or any part or installment
thereof) shall be exercised by giving written notice to the Company at its
principal office address, or to such transfer agent as the Company shall
designate. Such notice shall identify the Option being exercised and specify the
number of shares as to which such Option is being exercised, accompanied by full
payment of the purchase price therefor either (a) in United States dollars in
cash or by check, (b) at the discretion of the Committee, through delivery of
shares of Common Stock having a fair market value equal as of the date of the
exercise to the cash exercise price of the Option, (c) at the discretion of the
Committee, by delivery of the optionee's personal recourse note bearing interest
payable not less than annually at no less than 100% of the lowest applicable
Federal rate, as defined in Section 1274(d) of the Code, (d) at the discretion
of the Committee and consistent with applicable law, through the delivery of an
assignment to the Company of a sufficient amount of the proceeds from the sale
of the Common Stock acquired upon exercise of the Option and an authorization to
the broker or selling agent to pay that amount to the Company, which sale shall
be at the participant's direction at the time of exercise, or (e) at the
discretion of the Committee, by any combination of (a), (b), (c) and (d) above.
If the Committee exercises its discretion to permit payment of the exercise
price of an ISO by means of the methods set forth in clauses (b), (c), (d) or
(e) of the preceding sentence, such discretion shall be exercised in writing at
the time of the grant of the ISO in question. The holder of an Option shall not
have the rights of a shareholder with respect to the shares covered by such
Option until the date of issuance of a stock certificate to such holder for such
shares. Except as expressly provided above in paragraph 13 with respect to
changes in capitalization and stock dividends, no adjustment shall be made for
dividends or similar rights for which the record date is before the date such
stock certificate is issued.

     15.  TERM AND AMENDMENT OF PLAN.  This Plan was adopted by the Board in
July 1997 and by the stockholders of the Company on September 9, 1997. The Plan
was amended on March 12, 1998 to increase the number of shares authorized for
issuance under the Plan by 750,000 shares to 1,500,000, and such amendment was
approved by the stockholders of the Company at the Annual Meeting held on April
30, 1998. On March 1, 1999, the Board of Directors further amended the Plan to
increase the number of shares authorized for issuance under the Plan by
1,000,000 shares to 2,500,000 shares and to make certain other minor
modifications, subject to approval of the amendment of the Plan by the
stockholders of the Company at the next Meeting of Stockholders. If the approval
of the amendment by the stockholders is not obtained prior

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to March 1, 2000, any grants of ISOs under the Plan which include shares from
the additional number of shares authorized by the amendment made prior to that
date but subsequent to the date of the amendment will be rescinded. The Plan
shall expire at the end of the day on October 15, 2007 (except as to Options
outstanding on that date). Subject to the provisions of paragraph 5 above,
Options may be granted under the Plan prior to the date of stockholder approval
of the Plan. The Board may terminate or amend the Plan in any respect at any
time, except that, without the approval of the stockholders obtained within 12
months before or after the Board adopts a resolution authorizing any of the
following actions: (a) the total number of shares that may be issued under the
Plan may not be increased (except by adjustment pursuant to paragraph 13); (b)
the provisions of paragraph 3 regarding eligibility for grants of ISOs may not
be modified; (c) the provisions of paragraph 6(B) regarding the exercise price
at which shares may be offered pursuant to ISOs may not be modified (except by
adjustment pursuant to paragraph 13); and (d) the expiration date of the Plan
may not be extended. Except as otherwise provided in this paragraph 15, in no
event may action of the Board or stockholders alter or impair the rights of a
grantee, without such grantee's consent, under any Stock Right previously
granted to such grantee.

     16.  MODIFICATIONS OF ISOS; CONVERSION OF ISOS INTO NON-QUALIFIED
OPTIONS.  Subject to paragraph 13(D), without the prior written consent of the
holder of an ISO, the Committee shall not alter the terms of such ISO (including
the means of exercising such ISO) if such alteration would constitute a
modification (within the meaning of Section 424(h)(3) of the Code). The
Committee, at the written request or with the written consent of any optionee,
may in its discretion take such actions as may be necessary to convert such
optionee's ISOs (or any installments or portions of installments thereof) that
have not been exercised on the date of conversion into Non-Qualified Options at
any time prior to the expiration of such ISOs, regardless of whether the
optionee is an employee of the Company or a Related Corporation at the time of
such conversion. Such actions may include, but shall not be limited to,
extending the exercise period of such ISOs. At the time of such conversion, the
Committee (with the consent of the optionee) may impose such conditions on the
exercise of the resulting Non-Qualified Options as the Committee in its
discretion may determine, provided that such conditions shall not be
inconsistent with this Plan. Nothing in the Plan shall be deemed to give any
optionee the right to have such optionee's ISOs converted into Non-Qualified
Options, and no such conversion shall occur until and unless the Committee takes
appropriate action. Upon the taking of such action, the Company shall issue
separate certificates to the optionee with respect to Options that are
Non-Qualified Options and Options that are ISOs. The Committee, with the consent
of the optionee, may also terminate any portion of any ISO that has not been
exercised at the time of such conversion.

     17.  APPLICATION OF FUNDS.  The proceeds received by the Company from the
sale of shares pursuant to Options granted and Purchases authorized under the
Plan shall be used for general corporate purposes.

     18.  NOTICE TO COMPANY OF DISQUALIFYING DISPOSITION.  By accepting an ISO
granted under the Plan, each optionee agrees to notify the Company in writing
immediately after such optionee makes a Disqualifying Disposition (as described
in Sections 421, 422 and 424 of the Code and regulations thereunder) of any
stock acquired pursuant to the exercise of ISOs granted under the Plan. A
Disqualifying Disposition is generally any disposition occurring on or before
the later of (a) the date two years following the date the ISO was granted or
(b) the date one year following the date the ISO was exercised.

     19.  WITHHOLDING OF ADDITIONAL INCOME TAXES.  Upon the exercise of a
Non-Qualified Option, the transfer of a Non-Qualified Stock Option pursuant to
an arm's-length transaction, the grant of an Award, the making of a Purchase of
Common Stock for less than its fair market value, the making of a Disqualifying
Disposition (as defined in paragraph 18), the vesting or transfer of restricted
stock or securities acquired on the exercise of an Option hereunder, or the
making of a distribution or other payment with respect to such stock or
securities, the Company may withhold, or may require the grantee to pay,
additional withholding taxes in respect of amounts that constitute compensation
includible in gross income. The Committee in its

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discretion may condition (i) the exercise of an Option, (ii) the transfer of a
Non-Qualified Stock Option, (iii) the grant of an Award, (iv) the making of a
Purchase of Common Stock for less than its fair market value, or (v) the vesting
or transferability of restricted stock or securities acquired by exercising an
Option, on the grantee's making satisfactory arrangement for such withholding.
Such arrangement may include payment by the grantee in cash or by check of the
amount of the withholding taxes or, at the discretion of the Committee, by the
grantee's delivery of previously held shares of Common Stock or the withholding
from the shares of Common Stock otherwise deliverable upon exercise of a Option
shares having an aggregate fair market value equal to the amount of such
withholding taxes.

     20.  GOVERNMENTAL REGULATION.  The Company's obligation to sell and deliver
shares of the Common Stock under this Plan is subject to the approval of any
governmental authority required in connection with the authorization, issuance
or sale of such shares. Government regulations may impose reporting or other
obligations on the Company with respect to the Plan. For example, the Company
may be required to send tax information statements to employees and former
employees that exercise ISOs under the Plan, and the Company may be required to
file tax information returns reporting the income received by grantees of
Options in connection with the Plan.

     21.  GOVERNING LAW.  The validity and construction of the Plan and the
instruments evidencing Stock Rights shall be governed by the laws of the
Commonwealth of Massachusetts, or the laws of any jurisdiction in which the
Company or its successors in interest may be organized.

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