<PAGE>

                                                                     EXHIBIT 4.2

                  THIRD RESTATED INVESTORS' RIGHTS AGREEMENT

                                PLACEWARE, INC.

                              September 17, 1999
<PAGE>

                               TABLE OF CONTENTS
                               -----------------

<TABLE>
<S>                                                                             <C>
1. Registration Rights........................................................   1
     1.1  Definitions.........................................................   1
     1.2  Request for Registration............................................   2
     1.3  Company Registration................................................   4
     1.4  Obligations of the Company..........................................   4
     1.5  Furnish Information.................................................   5
     1.6  Expenses of Demand Registration.....................................   5
     1.7  Expenses of Company Registration....................................   6
     1.8  Underwriting Requirements...........................................   6
     1.9  Delay of Registration...............................................   7
     1.10  Indemnification....................................................   7
     1.11  Reports Under Securities Exchange Act of 1934......................   9
     1.12  Form S-3 Registration..............................................   9
     1.13  Assignment of Registration Rights..................................  10
     1.14  Limitations on Subsequent Registration Rights......................  11
     1.15  "Market Stand-Off" Agreement Rights................................  11
     1.16  Termination of Registration Rights.................................  11

2. Covenants of the Company...................................................  12
     2.1  Delivery of Financial Statements....................................  12
     2.2  Inspection..........................................................  12
     2.3  Termination of Information and Inspection Covenants.................  13
     2.4  Right of First Offer................................................  13
     2.5  Observer Rights.....................................................  14
     2.6  Directors' Liability and Indemnification............................  15
     2.7  Proprietary Information and Inventions Agreement....................  15
     2.8  Certain Covenants Relating to SBA Matters...........................  15
     2.9  Committees of the Board.............................................  17
     2.10  Audit Committee of the Board.......................................  17

3. Miscellaneous..............................................................  17
     3.1  Successors and Assigns..............................................  17
     3.2  Governing Law.......................................................  17
     3.3  Counterparts........................................................  18
     3.4  Titles and Subtitles................................................  18
     3.5  Notices.............................................................  18
     3.6  Expenses............................................................  18
     3.7  Amendments and Waivers..............................................  18
     3.8  Severability........................................................  18
     3.9  Aggregation of Stock................................................  18
     3.10  Entire Agreement...................................................  19
     3.11  Termination of Prior Agreement.....................................  19
</TABLE>

Schedule A  Schedule of Investors
Schedule B  Schedule of Management Holders

                                       i
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                  THIRD RESTATED INVESTORS' RIGHTS AGREEMENT
                  ------------------------------------------

          THIS THIRD RESTATED INVESTORS' RIGHTS AGREEMENT is made as of
September 17, 1999, by and among PlaceWare, Inc., a Delaware corporation (the
"Company"), the investors listed on Schedule A hereto, each of which is herein
referred to as an "Investor," and the management holders listed on Schedule B
hereto, each of which is herein referred to as a "Management Holder."

                                   RECITALS
                                   --------

          WHEREAS, certain of the Investors holding Series A Preferred Stock
(the "Series A Investors"), certain of the Investors holding Series B Preferred
Stock (the "Series B Investors") and the Management Holders possess registration
and other rights granted pursuant to the PlaceWare, Inc. Second Restated
Investors' Rights Agreement by and among the Company, the Series A Investors,
the Series B Investors and Management Holders named therein, dated May 22, 1998
(the "Prior Agreement"), entered into in connection with that certain Second
Series B Preferred Stock Purchase Agreement, dated May 22, 1998, by and among
the Company and the Investors named therein;

          WHEREAS, the Prior Agreement may be amended, and any provision therein
waived, with the consent of the Company, the Series A Investors, the Series B
Investors and the Management Holders holding a majority of the "Registrable
Securities" of the Company (as defined in the Prior Agreement);

          WHEREAS, certain of the Investors are parties to the PlaceWare, Inc.
Series C Preferred Stock Purchase Agreement (the "Series C Agreement") of even
date herewith by and among the Company and the Investors listed on Schedule A
thereto (the "Series C Investors");

          WHEREAS, in order to induce the Company to enter into the Series C
Agreement and to induce the Series C Investors to invest funds in the Company
pursuant to the Series C Agreement, the Series A Investors, the Series B
Investors and Management Holders desire to waive, amend and restate all rights
granted to them under the Prior Agreement, to terminate the Prior Agreement, and
to replace the Prior Agreement in its entirety as set forth herein; and

          WHEREAS, the Series C Investors and the Company have agreed, pursuant
to the Series C Agreement, to enter into this Agreement.

          NOW, THEREFORE, THE PARTIES HEREBY CONSENT TO THE ISSUANCE OF SERIES B
PREFERRED STOCK PURSUANT TO THE SECOND SERIES B AGREEMENT AND AGREE AS FOLLOWS:

          1.   Registration Rights. The Company covenants and agrees as follows:
               -------------------

          1.1  Definitions.  For purposes of this Section 1:
               -----------

          (a)  The term "Act" means the Securities Act of 1933, as amended.
<PAGE>

          (b)  The term "Form S-3" means such form under the Act as in effect on
the date hereof or any registration form under the Act subsequently adopted by
the SEC that permits inclusion or incorporation of substantial information by
reference to other documents filed by the Company with the SEC.

          (c)  The term "Holder" means any person owning or having the right to
acquire Registrable Securities or any assignee thereof in accordance with
Section 1.13 hereof.

          (d)  The term "1934 Act" shall mean the Securities Exchange Act of
1934, as amended.

          (e)  The term "register," "registered," and "registration" refer to a
registration effected by preparing and filing a registration statement or
similar document in compliance with the Act, and the declaration or ordering of
effectiveness of such registration statement or document.

          (f)  The term "Registrable Securities" means (i) the Common Stock
issuable or issued upon conversion of the Series A Preferred Stock, Series B
Preferred Stock and Series C Preferred Stock, (ii) the shares of Common Stock
issued to the Management Holders; provided, however, that such shares of Common
Stock shall not be deemed Registrable Securities and the aforementioned
individuals shall not be deemed Holders for the purposes of Section 1.2, 1.12
and 3.7 hereof, and (iii) any Common Stock of the Company issued as (or issuable
upon the conversion or exercise of any warrant, right or other security that is
issued as) a dividend or other distribution with respect to, or in exchange for,
or in replacement of the shares referenced in (i) and (ii) above, excluding in
all cases, however, any Registrable Securities sold by a person in a transaction
in which his rights under this Section 1 are not assigned.

          (g)  The number of shares of "Registrable Securities then outstanding"
shall be determined by the number of shares of Common Stock outstanding that
are, and the number of shares of Common Stock issuable pursuant to then
exercisable or convertible securities that are, Registrable Securities.

          (h)  The term "SEC" shall mean the Securities and Exchange Commission.

          1.2  Request for Registration.
               ------------------------

          (a)  If the Company shall receive at any time after the earlier of (i)
January 1, 2001, or (ii) six (6) months after the effective date of the first
registration statement for a public offering of securities of the Company (other
than a registration statement relating either to the sale of securities to
employees of the Company pursuant to a stock option, stock purchase or similar
plan or a SEC Rule 145 transaction), a written request from Holders that the
Company file a registration statement under the Act covering the registration of
at least thirty percent (30%) of the Registrable Securities then outstanding and
having an aggregate offering price, net of underwriting discounts and
commissions, of at least $10,000,000, then the Company shall:

               (i)    within ten (10) days of the receipt thereof, give written
notice of such request to all Holders; and

                                       2
<PAGE>

               (ii)   effect as soon as practicable, and in any event within
sixty (60) days of the receipt of such request, the registration under the Act
of all Registrable Securities that the Holders request to be registered, subject
to the limitations of subsection 1.2(b), within twenty (20) days of the mailing
of such notice by the Company in accordance with Section 3.5.

          (b)  If the Holders initiating the registration request hereunder
("Initiating Holders") intend to distribute the Registrable Securities covered
by their request by means of an underwriting, they shall so advise the Company
as a part of their request made pursuant to subsection 1.2(a) and the Company
shall include such information in the written notice referred to in subsection
1.2(a). The underwriter will be selected by the Company and shall be reasonably
acceptable to a majority in interest of the Initiating Holders. In such event,
the right of any Holder to include his Registrable Securities in such
registration shall be conditioned upon such Holder's participation in such
underwriting and the inclusion of such Holder's Registrable Securities in the
underwriting (unless otherwise mutually agreed by a majority in interest of the
Initiating Holders and such Holder) to the extent provided herein. All Holders
proposing to distribute their securities through such underwriting shall
(together with the Company as provided in subsection 1.4(e)) enter into an
underwriting agreement in customary form with the underwriter or underwriters
selected for such underwriting. Notwithstanding any other provision of this
Section 1.2, if the underwriter advises the Initiating Holders in writing that
marketing factors require a limitation of the number of shares to be
underwritten, then the Initiating Holders shall so advise all Holders of
Registrable Securities that would otherwise be underwritten pursuant hereto, and
the number of shares of Registrable Securities that may be included in the
underwriting shall be allocated among all Holders thereof, including the
Initiating Holders, in proportion (as nearly as practicable) to the amount of
Registrable Securities of the Company owned by each Holder; provided, however,
that the number of shares of Registrable Securities to be included in such
underwriting shall not be reduced unless all other securities are first entirely
excluded from the underwriting.

          (c)  Notwithstanding the foregoing, if the Company shall furnish to
Holders requesting a registration statement pursuant to this Section 1.2, a
certificate signed by the Chief Executive Officer of the Company stating that in
the good faith judgment of the Board of Directors of the Company, it would be
seriously detrimental to the Company and its stockholders for such registration
statement to be filed and it is therefore essential to defer the filing of such
registration statement, the Company shall have the right to defer taking action
with respect to such filing for a period of not more than one hundred twenty
(120) days after receipt of the request of the Initiating Holders; provided,
however, that the Company may not utilize this right more than once in any
twelve (12) month period.

          (d)  In addition, the Company shall not be obligated to effect, or to
take any action to effect, any registration pursuant to this Section 1.2:

               (i)    After the Company has effected two (2) registrations
pursuant to this Section 1.2 and such registrations have been declared or
ordered effective;

               (ii)   During the period starting with the date sixty (60) days
prior to the Company's good faith estimate of the date of filing of, and ending
on a date one hundred eighty

                                       3
<PAGE>

(180) days after the effective date of, a registration subject to Section 1.3
hereof; provided that the Company is actively employing in good faith all
reasonable efforts to cause such registration statement to become effective; or

               (iii)  If the Initiating Holders propose to dispose of shares of
Registrable Securities that may be immediately registered on Form S-3 pursuant
to a request made pursuant to Section 1.12 below.

          1.3  Company Registration.  If (but without any obligation to do so)
               --------------------
the Company proposes to register (including for this purpose a registration
effected by the Company for stockholders other than the Holders) any of its
stock or other securities under the Act in connection with the public offering
of such securities solely for cash (other than a registration relating solely to
the sale of securities to participants in a Company stock plan, a registration
on any form that does not include substantially the same information as would be
required to be included in a registration statement covering the sale of the
Registrable Securities or a registration in which the only Common Stock being
registered is Common Stock issuable upon conversion of debt securities that are
also being registered), the Company shall, at such time, promptly give each
Holder written notice of such registration. Upon the written request of each
Holder given within twenty (20) days after mailing of such notice by the Company
in accordance with Section 3.5, the Company shall, subject to the provisions of
Section 1.8, cause to be registered under the Act all of the Registrable
Securities that each such Holder has requested to be registered.

          1.4  Obligations of the Company.  Whenever required under this Section
               --------------------------
1 to effect the registration of any Registrable Securities, the Company shall,
as expeditiously as reasonably possible:

          (a)  Prepare and file with the SEC a registration statement with
respect to such Registrable Securities and use its best efforts to cause such
registration statement to become effective, and, upon the request of the Holders
of a majority of the Registrable Securities registered thereunder, keep such
registration statement effective for a period of up to one hundred twenty (120)
days or, if earlier, until the distribution contemplated in the Registration
Statement has been completed.

          (b)  Prepare and file with the SEC such amendments and supplements to
such registration statement and the prospectus used in connection with such
registration statement as may be necessary to comply with the provisions of the
Act with respect to the disposition of all securities covered by such
registration statement.

          (c)  Furnish to the Holders such numbers of copies of a prospectus,
including a preliminary prospectus, in conformity with the requirements of the
Act, and such other documents as they may reasonably request in order to
facilitate the disposition of Registrable Securities owned by them.

          (d)  Use its best efforts to register and qualify the securities
covered by such registration statement under such other securities or blue sky
laws of such jurisdictions as shall be reasonably requested by the Holders;
provided that the Company shall not be required in

                                       4
<PAGE>

connection therewith or as a condition thereto to qualify to do business or to
file a general consent to service of process in any such states or
jurisdictions.

          (e)  In the event of any underwritten public offering, enter into and
perform its obligations under an underwriting agreement, in usual and customary
form, with the managing underwriter of such offering. Each Holder participating
in such underwriting shall also enter into and perform its obligations under
such an agreement.

          (f)  Notify each Holder of Registrable Securities covered by such
registration statement at any time when a prospectus relating thereto is
required to be delivered under the Act of the happening of any event as a result
of which the prospectus included in such registration statement, as then in
effect, includes an untrue statement of a material fact or omits to state a
material fact required to be stated therein or necessary to make the statements
therein not misleading in the light of the circumstances then existing.

          (g)  Cause all such Registrable Securities registered pursuant
hereunder to be listed on each securities exchange on which similar securities
issued by the Company are then listed.

          (h)  Provide a transfer agent and registrar for all Registrable
Securities registered pursuant hereunder and a CUSIP number for all such
Registrable Securities, in each case not later than the effective date of such
registration.

          1.5  Furnish Information.
               -------------------

          (a)  It shall be a condition precedent to the obligations of the
Company to take any action pursuant to this Section 1 with respect to the
Registrable Securities of any selling Holder that such Holder shall furnish to
the Company such information regarding itself, the Registrable Securities held
by it, and the intended method of disposition of such securities as shall be
required to effect the registration of such Holder's Registrable Securities.

          (b)  The Company shall have no obligation with respect to any
registration requested pursuant to Section 1.2 or Section 1.12 if, due to the
operation of subsection 1.5(a), the number of shares or the anticipated
aggregate offering price of the Registrable Securities to be included in the
registration does not equal or exceed the number of shares or the anticipated
aggregate offering price required to originally trigger the Company's obligation
to initiate such registration as specified in subsection 1.2(a) or subsection
1.12(b)(2), whichever is applicable.

          1.6  Expenses of Demand Registration.  All expenses other than
               -------------------------------
underwriting discounts and commissions incurred in connection with
registrations, filings or qualifications pursuant to Section 1.2, including
(without limitation) all registration, filing and qualification fees, printers'
and accounting fees, fees and disbursements of counsel for the Company and the
reasonable fees and disbursements of one counsel for the selling Holders shall
be borne by the Company; provided, however, that the Company shall not be
required to pay for any expenses of any registration proceeding begun pursuant
to Section 1.2 if the registration request is subsequently withdrawn at the
request of the Holders of a majority of the Registrable Securities to be
registered (in which case all participating Holders shall bear such expenses),
unless the Holders of a majority of the Registrable Securities agree to forfeit
their right to one demand

                                       5
<PAGE>

registration pursuant to Section 1.2; provided further, however, that if at the
time of such withdrawal, the Holders have learned of a material adverse change
in the condition, business, or prospects of the Company from that known to the
Holders at the time of their request and have withdrawn the request with
reasonable promptness following disclosure by the Company of such material
adverse change, then the Holders shall not be required to pay any of such
expenses and shall retain their rights pursuant to Section 1.2.

          1.7  Expenses of Company Registration.  The Company shall bear and
               --------------------------------
pay all expenses incurred in connection with any registration, filing or
qualification of Registrable Securities with respect to the registrations
pursuant to Section 1.3 for each Holder (which right may be assigned as provided
in Section 1.13), including (without limitation) all registration, filing, and
qualification fees, printers and accounting fees relating or apportionable
thereto and the fees and disbursements of one counsel for the selling Holders
selected by them, but excluding underwriting discounts and commissions relating
to Registrable Securities.

          1.8  Underwriting Requirements.  In connection with any offering
               -------------------------
involving an underwriting of shares of the Company's capital stock, the Company
shall not be required under Section 1.3 to include any of the Holders'
securities in such underwriting unless they accept the terms of the underwriting
as agreed upon between the Company and the underwriters selected by it (or by
other persons entitled to select the underwriters), and then only in such
quantity as the underwriters determine in their sole discretion will not
jeopardize the success of the offering by the Company. If the total amount of
securities, including Registrable Securities, requested by stockholders to be
included in such offering exceeds the amount of securities sold other than by
the Company that the underwriters determine in good faith and in their sole
discretion is compatible with the success of the offering, then the Company
shall be required to include in the offering only that number of such
securities, including Registrable Securities, that the underwriters determine in
good faith and in their sole discretion will not jeopardize the success of the
offering (the securities so included to be apportioned pro rata among the
selling stockholders according to the total amount of securities entitled to be
included therein owned by each selling stockholder or in such other proportions
as shall mutually be agreed to by such selling stockholders) but in no event
shall (i) the amount of securities of the selling Holders included in the
offering be reduced below twenty-five percent (25%) of the total amount of
securities included in such offering, unless such offering is the initial public
offering of the Company's securities, in which case the selling stockholders may
be excluded if the underwriters make the determination described above and no
other stockholder's securities are included or (ii) notwithstanding (i) above,
any shares being sold by a stockholder exercising a demand registration right
similar to that granted in Section 1.2 be excluded from such offering. For
purposes of the preceding parenthetical concerning apportionment, for any
selling stockholder that is a holder of Registrable Securities and that is a
partnership or corporation, the partners, retired partners and stockholders of
such holder, or the estates and family members of any such partners and retired
partners and any trusts for the benefit of any of the foregoing persons shall be
deemed to be a single "selling stockholder," and any pro-rata reduction with
respect to such "selling stockholder" shall be based upon the aggregate amount
of shares carrying registration rights owned by all entities and individuals
included in such "selling stockholder," as defined in this sentence. If any
selling Holder disapproves of the terms of any underwriting under Section 1.3,
such Holder may elect to withdraw any of its securities included in such
underwriting by written notice to the Company and the underwriter, delivered at
least fifteen (15)

                                       6
<PAGE>

business days prior to the effective date of the registration statement. Any
Registrable Securities excluded or withdrawn from such underwriting shall be
excluded and withdrawn from the registration.

          1.9  Delay of Registration.  No Holder shall have any right to obtain
               ---------------------
or seek an injunction restraining or otherwise delaying any such registration as
the result of any controversy that might arise with respect to the
interpretation or implementation of this Section 1.

          1.10 Indemnification.  In the event any Registrable Securities are
               ---------------
included in a registration statement under this Section 1:

          (a)  To the extent permitted by law, the Company will indemnify and
hold harmless each Holder, the partners, officers and directors of each Holder,
any underwriter (as defined in the Act) for such Holder, and each person, if
any, who controls such Holder or underwriter within the meaning of the Act or
the 1934 Act, against any losses, claims, damages, or liabilities (joint or
several) to which they may become subject under the Act, the 1934 Act or other
federal or state law, insofar as such losses, claims, damages, or liabilities
(or actions in respect thereof) arise out of or are based upon any of the
following statements, omissions or violations (collectively, a "Violation"): (i)
any untrue statement or alleged untrue statement of a material fact contained in
such registration statement, including any preliminary prospectus or final
prospectus contained therein or any amendments or supplements thereto, (ii) the
omission or alleged omission to state therein a material fact required to be
stated therein, or necessary to make the statements therein not misleading, or
(iii) any violation or alleged violation by the Company of the Act, the 1934
Act, any state securities law or any rule or regulation promulgated under the
Act, the 1934 Act or any state securities law; and the Company will pay to each
such Holder, partner, officer, director, underwriter or controlling person, as
incurred, any legal or other expenses reasonably incurred by them in connection
with investigating or defending any such loss, claim, damage, liability or
action; provided, however, that the indemnity agreement contained in this
subsection 1.10(a) shall not apply to amounts paid in settlement of any such
loss, claim, damage, liability or action if such settlement is effected without
the consent of the Company (which consent shall not be unreasonably withheld),
nor shall the Company be liable in any such case for any such loss, claim,
damage, liability or action to the extent that it arises out of or is based upon
a Violation that occurs in reliance upon and in conformity with written
information furnished expressly for use in connection with such registration by
any such Holder, partner, officer, director, underwriter or controlling person.

          (b)  To the extent permitted by law, each selling Holder will
indemnify and hold harmless the Company, each of its directors, each of its
officers who has signed the registration statement, each person, if any, who
controls the Company within the meaning of the Act, any underwriter, any other
Holder selling securities in such registration statement and any partner,
officer, director or controlling person of any such underwriter or other Holder,
against any losses, claims, damages or liabilities (severally, and not jointly)
to which any of the foregoing persons may become subject under the Act, the 1934
Act or other federal or state law, insofar as such losses, claims, damages or
liabilities (or actions in respect thereto) arise out of or are based upon any
Violation, in each case to the extent (and only to the extent) that such
Violation occurs in reliance upon and in conformity with written information
furnished by such Holder expressly for use in connection with such registration;
and each such Holder will pay, as

                                       7
<PAGE>

incurred, any legal or other expenses reasonably incurred by any person intended
to be indemnified pursuant to this subsection 1.10(b) in connection with
investigating or defending any such loss, claim, damage, liability or action;
provided, however, that the indemnity agreement contained in this subsection
1.10(b) shall not apply to amounts paid in settlement of any such loss, claim,
damage, liability or action if such settlement is effected without the consent
of the Holder (which consent shall not be unreasonably withheld); provided that
in no event shall any indemnity under this subsection 1.10(b) exceed the net
proceeds from the offering received by such Holder.

          (c)  Promptly after receipt by an indemnified party under this Section
1.10 of notice of the commencement of any action (including any governmental
action), such indemnified party will, if a claim in respect thereof is to be
made against any indemnifying party under this Section 1.10, deliver to the
indemnifying party a written notice of the commencement thereof and the
indemnifying party shall have the right to participate in, and, to the extent
the indemnifying party so desires, jointly with any other indemnifying party
similarly noticed, to assume the defense thereof with counsel mutually
satisfactory to the parties; provided, however, that an indemnified party
(together with all other indemnified parties that may be represented without
conflict by one counsel) shall have the right to retain one separate counsel,
with the fees and expenses to be paid by the indemnifying party, if
representation of such indemnified party by the counsel retained by the
indemnifying party would be inappropriate due to actual or potential differing
interests between such indemnified party and any other party represented by such
counsel in such proceeding. The failure to deliver written notice to the
indemnifying party within a reasonable time of the commencement of any such
action, if prejudicial to its ability to defend such action, shall relieve such
indemnifying party of any liability to the indemnified party under this Section
1.10, but the omission so to deliver written notice to the indemnifying party
will not relieve it of any liability that it may have to any indemnified party
otherwise than under this Section 1.10.


          (d)  If the indemnification provided for in this Section 1.10 is held
by a court of competent jurisdiction to be unavailable to an indemnified party
with respect to any loss, liability, claim, damage or expense referred to
therein, then the indemnifying party, in lieu of indemnifying such indemnified
party hereunder, shall contribute to the amount paid or payable by such
indemnified party as a result of such loss, liability, claim, damage or expense
in such proportion as is appropriate to reflect the relative fault of the
indemnifying party on the one hand and of the indemnified party on the other in
connection with the statements or omissions that resulted in such loss,
liability, claim, damage or expense as well as any other relevant equitable
considerations. The relative fault of the indemnifying party and of the
indemnified party shall be determined by reference to, among other things,
whether the untrue or alleged untrue statement of a material fact or the
omission to state a material fact relates to information supplied by the
indemnifying party or by the indemnified party and the parties' relative intent,
knowledge, access to information and opportunity to correct or prevent such
statement or omission. In no event shall any contribution under this subsection
1.10(d) exceed the net proceeds from the offering received by such holder.

          (e)  The obligations of the Company and Holders under this Section
1.10 shall survive the completion of any offering of Registrable Securities in a
registration statement under this Section 1, and otherwise.

                                       8
<PAGE>

          (f)  No indemnifying party, in the defense of any such claim or
litigation, shall, except with the consent of each indemnified party, consent to
entry to any judgment or enter into any settlement which does not include as an
unconditional term thereof the giving by the claimant or plaintiff to such
indemnified party of a release from all liability in respect to such claim or
litigation.

          1.11 Reports Under Securities Exchange Act of 1934.  With a view to
               ---------------------------------------------
making available to the Holders the benefits of Rule 144 promulgated under the
Act and any other rule or regulation of the SEC that may at any time permit a
Holder to sell securities of the Company to the public without registration or
pursuant to a registration on Form S-3, the Company agrees to:

          (a)  make and keep public information available, as those terms are
understood and defined in SEC Rule 144, at all times after the effective date of
the first registration statement filed by the Company for the offering of its
securities to the general public;

          (b)  take such action, including the voluntary registration of its
Common Stock under Section 12 of the 1934 Act, as is necessary to enable the
Holders to utilize Form S-3 for the sale of their Registrable Securities, such
action to be taken as soon as practicable after the end of the fiscal year in
which the first registration statement filed by the Company for the offering of
its securities to the general public is declared effective;

          (c)  file with the SEC in a timely manner all reports and other
documents required of the Company under the Act and the 1934 Act; and

          (d)  furnish to any Holder, so long as the Holder owns any Registrable
Securities, forthwith upon request (i) a written statement by the Company that
it has complied with the reporting requirements of SEC Rule 144 (at any time
after ninety (90) days after the effective date of the first registration
statement filed by the Company), the Act and the 1934 Act (at any time after it
has become subject to such reporting requirements), or that it qualifies as a
registrant whose securities may be resold pursuant to Form S-3 (at any time
after it so qualifies), (ii) a copy of the most recent annual or quarterly
report of the Company and such other reports and documents so filed by the
Company, and (iii) such other information as may be reasonably requested in
availing any Holder of any rule or regulation of the SEC that permits the
selling of any such securities without registration or pursuant to such form.

          1.12 Form S-3 Registration.  In case the Company shall receive from
               ---------------------
any Holder or Holders holding at least ten percent (10%) of the outstanding
Registrable Securities a written request or requests that the Company effect a
registration on Form S-3 and any related qualification or compliance with
respect to all or a part of the Registrable Securities owned by such Holder or
Holders, the Company will:

          (a)  promptly give written notice of the proposed registration, and
any related qualification or compliance, to all other Holders; and

          (b)  as soon as practicable, effect such registration and all such
qualifications and compliances as may be so requested and as would permit or
facilitate the sale and distribution of all or such portion of such Holder's or
Holders' Registrable Securities as are specified in such request, together with
all or such portion of the Registrable Securities of any

                                       9
<PAGE>

other Holder or Holders joining in such request as are specified in a written
request given within fifteen (15) days after receipt of such written notice from
the Company; provided, however, that the Company shall not be obligated to
effect any such registration, qualification or compliance, pursuant to this
section 1.12: (1) if Form S-3 is not available for such offering by the Holders;
(2) if the Holders, together with the holders of any other securities of the
Company entitled to inclusion in such registration, propose to sell Registrable
Securities and such other securities (if any) at an aggregate price to the
public (net of any underwriters' discounts or commissions) of less than
$1,000,000; (3) if the Company shall furnish to the Holders a certificate signed
by the President of the Company stating that in the good faith judgment of the
Board of Directors of the Company, it would be seriously detrimental to the
Company and its stockholders for such Form S-3 Registration to be effected at
such time, in which event the Company shall have the right to defer the filing
of the Form S-3 registration statement for a period of not more than one hundred
twenty (120) days after receipt of the request of the Holder or Holders under
this Section 1.12; provided, however, that the Company shall not utilize this
right more than once in any twelve (12) month period; (4) if the Company has,
within the six (6) month period preceding the date of such request, already
effected one (1) registration on Form S-3 for the Holders pursuant to this
Section 1.12; or (5) in any particular jurisdiction in which the Company would
be required to qualify to do business or to execute a general consent to service
of process in effecting such registration, qualification or compliance.

          (c)  Subject to the foregoing, the Company shall file a registration
statement covering the Registrable Securities and other securities so requested
to be registered as soon as practicable after receipt of the request or requests
of the Holders. All expenses incurred in connection with a registration
requested pursuant to Section 1.12, including (without limitation) all
registration, filing, qualification, printer's and accounting fees and the
reasonable fees and disbursements of counsel for the selling Holder or Holders
and counsel for the Company, but excluding any underwriters' discounts or
commissions associated with Registrable Securities, shall be borne by the
Company. Registrations effected pursuant to this Section 1.12 shall not be
counted as demands for registration or registrations effected pursuant to
Sections 1.2 or 1.3, respectively.

          1.13 Assignment of Registration Rights.  The rights to cause the
               ---------------------------------
Company to register Registrable Securities pursuant to this Section 1 may be
assigned (but only with all related obligations) by a Holder to a transferee or
assignee of such securities who, after such assignment or transfer, holds at
least 100,000 shares of Registrable Securities (subject to appropriate
adjustment for stock splits, stock dividends, combinations and other
recapitalizations), provided: (a) the Company is, within a reasonable time after
such transfer, furnished with written notice of the name and address of such
transferee or assignee and the securities with respect to which such
registration rights are being assigned; (b) such transferee or assignee agrees
in writing to be bound by and subject to the terms and conditions of this
Agreement, including without limitation the provisions of Section 1.14 below;
and (c) such assignment shall be effective only if immediately following such
transfer the further disposition of such securities by the transferee or
assignee is restricted under the Act. For the purposes of determining the number
of shares of Registrable Securities held by a transferee or assignee, the
holdings of transferees and assignees of a partnership, corporation or limited
liability company who are partners, shareholders or members or retired partners,
former shareholders or members of such entity (including spouses and ancestors,
lineal descendants and siblings of such partners,

                                       10
<PAGE>

shareholders or members or spouses who acquire Registrable Securities by gift,
will or intestate succession) shall be aggregated together and with the entity;
provided that all assignees and transferees who would not qualify individually
for assignment of registration rights shall have a single attorney-in-fact for
the purpose of exercising any rights, receiving notices or taking any action
under this Section 1.

          1.14  Limitations on Subsequent Registration Rights. From and after
                ---------------------------------------------
the date of this Agreement, the Company shall not, without the prior written
consent of the Holders of a majority of the then outstanding shares of Series C
Preferred Stock, enter into any agreement with any holder or prospective holder
of any securities of the Company that would allow such holder or prospective
holder (a) to include such securities in any registration filed under Section
1.3 hereof, unless under the terms of such agreement, such holder or prospective
holder may include such securities in any such registration only to the extent
that the inclusion of such securities will not reduce the amount of the
Registrable Securities of the Holders that are included or (b) to demand
registration of their securities.

          1.15  "Market Stand-Off" Agreement Rights. Each Investor hereby agrees
                -----------------------------------
that, during the period of duration specified by the Company and an underwriter
of Common Stock or other securities of the Company, following the effective date
of a registration statement of the Company filed under the Act, it shall not, to
the extent requested by the Company and such underwriter, directly or indirectly
sell, offer to sell, contract to sell (including, without limitation, any short
sale), grant any option to purchase or otherwise transfer or dispose of (other
than to donees who agree to be similarly bound) any securities of the Company
held by it at any time during such period except Common Stock included in such
registration; provided, however, that:

          (a)  such agreement shall be applicable only to the first such
registration statement of the Company that covers Common Stock (or other
securities) to be sold on its behalf to the public in an underwritten offering;

          (b)  all officers and directors and greater than one percent (1%)
stockholders of the Company enter into similar agreements; and

          (c)  such market stand-off time period shall not exceed one hundred
eighty (180) days.

          In order to enforce the foregoing covenant, the Company may impose
stop-transfer instructions with respect to the Registrable Securities of each
Investor (and the shares or securities of every other person subject to the
foregoing restriction) until the end of such period.

          1.16  Termination of Registration Rights. No Holder shall be entitled
                ----------------------------------
to exercise any right provided for in this Section 1 after four (4) years
following the consummation of the sale of securities pursuant to a registration
statement filed by the Company under the Act in connection with the initial firm
commitment underwritten offering of its securities to the general public or, as
to any Holder, such earlier time at which (i) all Registrable Securities held by
such Holder can be sold in any three (3) month period without registration in
compliance with

                                       11
<PAGE>

Rule 144 of the Act and (ii) such Holder at that time holds less than one
percent (1%) of the Company's outstanding capital stock.

          2.   Covenants of the Company.
               ------------------------

          2.1   Delivery of Financial Statements. The Company shall deliver to
                --------------------------------
each Investor:

          (a)   as soon as practicable, but in any event within ninety (90) days
after the end of each fiscal year of the Company, an income statement for such
fiscal year, a balance sheet of the Company and statement of stockholder's
equity as of the end of such year, and a statement of cash flows for such year,
such year-end financial reports to be in reasonable detail, prepared in
accordance with generally accepted accounting principles ("GAAP"), and audited
and certified by independent public accountants of nationally recognized
standing selected by the Company;

          (b)   so long as such Investor holds at least 100,000 shares of
Preferred Stock (either in the form of Preferred Stock or Common Stock issued
upon conversion thereof, and as adjusted for subsequent stock splits,
recombinations or reclassifications), as soon as practicable, but in any event
within thirty (30) days after the end of each of the first three (3) quarters of
each fiscal year of the Company, an unaudited income statement and statement of
cash flows for such fiscal quarter and an unaudited balance sheet and a
statement of stockholder's equity as of the end of such fiscal quarter comparing
results to the annual plan;

          (c)  so long as such Investor holds at least 100,000 shares of
Preferred Stock (either in the form of Preferred Stock or Common Stock issued
upon conversion thereof, and as adjusted for subsequent stock splits,
recombinations or reclassifications), within thirty (30) days of the end of each
month, an unaudited income statement and statement of cash flows and balance
sheet for and as of the end of such month, in reasonable detail;

          (d)  so long as such Investor holds at least 100,000 shares of
Preferred Stock (either in the form of Preferred Stock or Common Stock issued
upon conversion thereof, and as adjusted for subsequent stock splits,
recombinations or reclassifications), as soon as practicable, but in any event
thirty (30) days prior to the end of each fiscal year, a budget for the next
fiscal year, prepared on a monthly basis, including balance sheets and
statements of cash flows, for such months, and, as soon as prepared, any other
budgets or revised budgets prepared by the Company; and

          (e)  with respect to the financial statements called for in
subsections (b) and (c) of this Section 2.1, an instrument executed by the Chief
Financial Officer or President of the Company certifying that such financials
were prepared in accordance with GAAP consistently applied with prior practice
for earlier periods (with the exception of footnotes that may be required by
GAAP) and fairly present the financial condition of the Company and its results
of operation for the period specified, subject to year-end audit adjustment.

          2.2   Inspection. The Company shall permit each Investor, at such
                ----------
Investor's expense, to visit and inspect the Company's properties, to examine
its books of account and records and to discuss the Company's affairs, finances
and accounts with its officers, all at such reasonable times as may be requested
by the Investor; provided, however, that the Company

                                       12
<PAGE>

shall not be obligated pursuant to this Section 2.2 to provide access to any
information that it reasonably considers to be a trade secret or similar
confidential information.

          2.3   Termination of Information and Inspection Covenants. The
                ---------------------------------------------------
covenants set forth in Section 2.1 and Section 2.2 shall terminate as to
Investors and be of no further force or effect when the sale of securities
pursuant to a registration statement filed by the Company under the Act in
connection with the firm commitment underwritten offering of its securities to
the general public is consummated or when the Company first becomes subject to
the periodic reporting requirements of Sections 12(g) or 15(d) of the 1934 Act,
whichever event shall first occur.

          2.4   Right of First Offer. Subject to the terms and conditions
                --------------------
specified in this paragraph 2.4, the Company hereby grants to each Investor a
right of first offer with respect to future sales by the Company of its Shares
(as hereinafter defined). An Investor shall be entitled to apportion the right
of first offer hereby granted it among itself and its partners and affiliates in
such proportions as it deems appropriate.

          Each time the Company proposes to offer any shares of, or securities
convertible into or exercisable for, any shares of any class of its capital
stock ("Shares"), the Company shall first make an offering of such Shares to
each Investor in accordance with the following provisions:

          (a)  The Company shall deliver a notice by certified mail ("Notice")
to the Investors stating (i) its bona fide intention to offer such Shares, (ii)
the number of such Shares to be offered, and (iii) the price and terms, if any,
upon which it proposes to offer such Shares.

          (b)  By written notification received by the Company, within twenty
(20) calendar days after giving of the Notice, the Investor may elect to
purchase or obtain, at the price and on the terms specified in the Notice, up to
that portion of such Shares that equals the proportion that the number of shares
of Common Stock issued and held, or issuable upon conversion of the Series A
Preferred Stock, Series B Preferred Stock and Series C Preferred Stock then
held, by such Investor bears to the total number of shares of Common Stock of
the Company then outstanding (assuming full conversion, exercise and exchange of
all convertible, exercisable or exchangeable securities).

          (c)  If all Shares that Investors are entitled to obtain pursuant to
subsection 2.4(b) are not elected to be obtained as provided in subsection
2.4(b) hereof, the Company may, during the ninety (90) day period following the
expiration of the period provided in subsection 2.4(b) hereof, offer the
remaining unsubscribed portion of such Shares to any person or persons at a
price not less than, and upon terms no more favorable to the offeree than those
specified in the Notice. If the Company does not enter into an agreement for the
sale of the Shares within such period, or if such agreement is not consummated
within sixty (60) days of the execution thereof, the right provided hereunder
shall be deemed to be revived and such Shares shall not be offered unless first
reoffered to the Investors in accordance herewith.

          (d)  The right of first offer in this paragraph 2.4 shall not be
applicable (i) to the issuance or sale of shares of Common Stock (or options
therefor) to employees or directors of

                                       13
<PAGE>

or consultants to the Company for the primary purpose of soliciting or retaining
their services, as approved by the Board of Directors, (ii) to or after
consummation of a bona fide, firmly underwritten public offering of shares of
Common Stock, registered under the Act pursuant to a registration statement on
Form S-1 or SB-2 (or any similar successor form), at an offering price of at
least $9.50 per share (appropriately adjusted for any stock split, dividend,
combination or other recapitalization) and $20,000,000 in the aggregate, (iii)
to the issuance of securities pursuant to the conversion, exercise or exchange
of convertible, exercisable or exchangeable securities, (iv) to the issuance of
securities in connection with a bona fide business acquisition of or by the
Company, whether by merger, consolidation, sale of assets, sale or exchange of
stock or otherwise, as approved by the Board of Directors, (v) to the issuance
of stock, warrants or other securities or rights to persons or entities with
which the Company has business relationships, provided such issuances are for
other than primarily equity financing purposes, as approved by the Board of
Directors, or (vi) to the issuance of shares of Series C Preferred Stock
pursuant to the Series C Agreement.

          (e)  The rights provided in this Section 2.4 shall terminate as to all
Investors and be of no further force or effect (i) when the sale of securities
pursuant to a registration statement filed by the Company under the Act in
connection with the firm commitment underwritten offering of its securities to
the general public is consummated, the public offering price of which was not
less than $9.50 per share (adjusted to reflect subsequent stock dividends, stock
splits or recapitalizations), and $20,000,000 in aggregate proceeds to the
Company or (ii) when the Company first becomes subject to the periodic reporting
requirements of Sections 12(g) or 15(d) of the 1934 Act, whichever event shall
first occur.

          2.5   Observer Rights. Subject to Section 4 of the Third Restated
                ---------------
Voting Agreement of even date herewith, as long as Xerox Corporation ("Xerox")
owns not less than 455,000 shares of Series A Preferred Stock or Common Stock
issued or issuable upon conversion thereof (as adjusted for any subsequent stock
dividends, combinations, splits or recapitalizations), the Company shall invite
Xerox to send at Xerox' own expense one (1) representative of Xerox reasonably
acceptable to the Company's Board of Directors to attend, in a nonvoting
observer capacity, each meeting of its Board of Directors; provided, however,
that such representative shall agree to hold in confidence and trust and to act
in a fiduciary manner with respect to all information provided in connection
with such meetings; and, provided further, that the Company reserves the right
to withhold any information and to exclude such representative from any meeting
or portion thereof if the Company believes access to such information or
attendance at such meeting or portion thereof could adversely affect the
attorney-client privilege between the Company and its counsel or would result in
disclosure of highly confidential proprietary information on matters where Xerox
or its representative may be a competitor of the Company. Xerox agrees, and any
representative of Xerox will agree, to hold in confidence and trust and not use
or disclose any confidential information provided to or learned by it in
connection with its rights under this Section 2.5(a), and such obligations will
survive any termination of this Section 2.5(a) or this Agreement. The rights
(but not the obligations) of Xerox under this Section 2.5(a) shall not be
assignable and shall terminate as to Xerox and be of no further force or effect
upon the earlier to occur of:

                (i)  the date upon which the Company or a parent of the Company
consummates a sale of securities pursuant to a registration statement filed by
the Company under

                                       14
<PAGE>

the Act in connection with the firm commitment underwritten offering of its
securities to the general public or the date upon which the Company first
becomes subject to the periodic reporting requirements of Section 12(g) or 15(d)
of the 1934 Act, whichever event shall first occur; or

                (ii) the date upon which the Company consummates (i) a
consolidation or merger of the Company or any affiliated corporation with or
into any other corporation or corporations (other than a consolidation or merger
of this Company with or into a wholly owned subsidiary of this Company), (ii) a
sale of all or substantially all of the assets or business of the Company in one
or more related transactions, (iii) a transaction or series of related
transactions (other than a public offering of the Company's securities) in which
the stockholders of the Company immediately prior to such transaction(s) own, as
a result of such transaction(s), less than a majority of the voting securities
of the successor or surviving corporation, which shall not be the Company in the
event of a consolidation or merger, immediately thereafter, or (iv) a
transaction or series of related transactions (other than a public offering of
the Company's securities) in which the Company issues shares representing more
than 50% of the voting power of the Company immediately after giving effect to
such transaction.

          2.6   Directors' Liability and Indemnification. The Company's Restated
                ----------------------------------------
Certificate of Incorporation and Bylaws shall provide (i) for elimination of the
liability of directors to the maximum extent permitted by law and (ii) for
indemnification of directors for acts on behalf of the Company to the maximum
extent permitted by law. In addition the Company shall use its best efforts to
retain such indemnification provisions.

          2.7   Proprietary Information and Inventions Agreement. The Company
                ------------------------------------------------
shall require all employees and consultants to execute and deliver a Proprietary
Information and Inventions Agreement in the form provided to the Investors.

          2.8   Certain Covenants Relating to SBA Matters.
                -----------------------------------------

          (a)   Use of Proceeds. The proceeds from the issuance and sale of the
Series C Stock pursuant to the Series C Agreement (the "Proceeds") shall be used
by the Company for its growth, modernization or expansion. The Company shall
provide each Investor which is a licensed Small Business Investment Company (an
"SBIC Investor") and the Small Business Administration (the "SBA") reasonable
access to the Company's books and records for the purpose of confirming the use
of Proceeds.

          (b)   Business Activity. For a period of one year following the
initial Closing under the Series C Agreement the Company shall not change the
nature of its business activity if such change would render the Company
ineligible as provided in 13 C.F.R. Section 107.720.

          (c)   Compliance. So long as any SBIC Investor holds any securities of
the Company, the Company will at all times comply with the non-discrimination
requirements of 13 C.F.R. Parts 112, 113 and 117.

          (d)   Information for SBIC Investor. Within 45 days after the end of
each fiscal year and at such other times as an SBIC Investor may reasonably
request, the Company shall

                                       15
<PAGE>

deliver to such SBIC Investor a written assessment, in form and substance
satisfactory to such SBIC Investor, of the economic impact of such investment,
and the impact of the financing on the Company's business in terms of profits
and on taxes paid by the Company and its employees. Upon request, the Company
agrees to promptly provide each SBIC Investor with sufficient information to
permit such Investor to comply with their obligations under the Small Business
Investment Act of 1958, as amended, and the regulations promulgated thereunder
and related thereto; provided, however, each SBIC Investor agrees that it will
protect any information which the Company labels as confidential to the extent
permitted by law. Any submission of any financial information under this Section
shall include a certificate of the company's president, chief executive officer,
treasurer or chief financial officer.

          (e)  For purposes of this Agreement, a "Regulatory Problem" means any
set of facts or circumstances wherein both (i) it has been asserted by any
governmental regulatory agency with jurisdiction over a SBIC Investor that such
SBIC Investor is not entitled to hold, or exercise any significant right with
respect to equity securities of the Company, including the Series C Preferred
Stock or the currently unissued Common Stock of the Company into which the
Series C Preferred Stock is convertible and (ii) such SBIC Investor reasonably
determines that such assertion is meritorious and that the solutions proposed by
such SBIC Investor is necessary to cure such regulatory violation by such SBIC
Investor. If a SBIC Investor determines that it has a Regulatory Problem, it
will so notify the Company and the other Investors as soon as practicable in
writing. After giving such notice, such SBIC Investor will have the right to
transfer its Series C Preferred Stock, and/or the shares of Common Stock
issuable upon conversion of such Series C Preferred Stock, without regard to any
restrictions on transfer set forth in this Agreement, the Series C Agreement or
any other Agreement identified herein or in the Series C Agreement
(collectively, the "Related Agreements") or in the Company's Certificate of
Incorporation or Bylaws, provided that the transferee agrees to become a party
to this Agreement, the Series C Agreement and/or to such relevant Related
Agreements, and acknowledges that such securities will become again, after such
transfer to such transferee, bound by all then relevant provisions relating to
further transfer thereof by transferee, and the Company will take all such
actions as are reasonably requested by such SBIC Investor in order to (i)
effectuate and facilitate any transfer by such SBIC Investor of any securities
of the Company then held by such SBIC Investor to any person designated by such
SBIC Investor, (ii) permit such SBIC Investor (or any of its affiliates) to
exchange all or any portion of any voting security of the Company then held by
such SBIC Investor on a share-for-share basis for shares of a nonvoting security
of the Company as will be created by action of the Board, and, to the extent
required by law, its stockholder, which nonvoting security will be identical in
all respects to the voting security exchanged for it, except that it will be
nonvoting and will be convertible into a voting security on such terms, solely
as required to allow such SBIC Investor to comply with then-applicable
regulatory considerations, as are requested by such SBIC Investor in good faith,
and (iii) amend, and use its reasonable efforts to cause other relevant parties,
including without limitation the Company's stockholders, to take such actions as
are legally required in order to amend this Agreement, the Series C Agreement,
the Related Agreements, the Company's Certificate of Incorporation, the
Company's Bylaws and related agreements and instruments in order to effectuate
and reflect the foregoing. The parties to this Agreement (other than the
Company) will vote all of the Company's voting securities held by them, and will
execute and

                                       16
<PAGE>

deliver all documents and instruments requested by them by the Company, in favor
of and to effect such amendments and actions.

          (f)  Number of Holders of Voting Securities. So long as any SBIC
Investor holds any securities purchased pursuant to the Purchase Agreement or
issued by the Company with respect thereto, the Company shall notify each SBIC
Investor (i) at least 15 days prior to taking any action after which the number
or record holders of the Company's voting securities would be increased from
fewer than 50 to 50 or more, and (ii) of any other action or occurrence after
which the number of record holders of the Company's voting securities was
increased (or would increase) from fewer than 50 to 50 or more, as soon as
practicable after the Company becomes aware that such other action or occurrence
has occurred or is proposed to occur.

          (g)  Termination of Obligations. The obligations of the Company under
any provision of this Section 2.8 shall terminate and be of no further force and
effect to the extent that (i) compliance with such provision is not required
under the Small Business Investment Company Act of 1958 as amended, or the rules
and regulations of the SBA thereunder, or (ii) an Investor is no longer a SBIC
Investor.

          2.9   Committees of the Board. As long as Apex is entitled to
                -----------------------
designate one individual to serve as a member of the Board of Directors of the
Company, such Apex designee shall be a member of the Compensation Committee and
any executive committee of the Board of Directors of the Company. As long as
BankAmerica Ventures is entitled to designate one individual to serve as a
member of the Board of Directors of the Company, such BankAmerica Ventures
designee shall be a member of the Compensation Committee and shall have equal
consideration to be on all committees of the Board of Directors. The
Compensation Committee of the Board of Directors of the Company shall have no
more than four (4) members (the "Compensation Committee Members") and shall have
the power and authority to approve compensation-related matters with respect to
executive officers of the Company and to administer the Company's 1997 Stock
Plan and any other stock or option plan of the Company. Two (2) of the
Compensation Committee Members shall be outside directors.

          2.10  Audit Committee of the Board. The Company shall establish an
                ----------------------------
Audit Committee within six months of the date of this Agreement. Members of the
Audit Committee shall be appointed by the Board of Directors.

          3.    Miscellaneous.
                -------------

          3.1   Successors and Assigns. Except as otherwise provided herein, the
                ----------------------
terms and conditions of this Agreement shall inure to the benefit of and be
binding upon the respective successors and assigns of the parties (including
transferees of any shares of Registrable Securities). Nothing in this Agreement,
express or implied, is intended to confer upon any party other than the parties
hereto or their respective successors and assigns any rights, remedies,
obligations, or liabilities under or by reason of this Agreement, except as
expressly provided in this Agreement.

          3.2   Governing Law. This Agreement shall be governed by and construed
                -------------
under the laws of the State of California as applied to agreements among
California residents

                                       17
<PAGE>

entered into and to be performed entirely within California, without reference
to California conflict of laws provisions.

          3.3   Counterparts. This Agreement may be executed in two or more
                ------------
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

          3.4   Titles and Subtitles. The titles and subtitles used in this
                --------------------
Agreement are used for convenience only and are not to be considered in
construing or interpreting this Agreement.

          3.5   Notices. Unless otherwise provided, any notice required or
                -------
permitted under this Agreement shall be given in writing and shall be deemed
effectively given upon personal delivery to the party to be notified or upon
deposit with the United States Post Office, by registered or certified mail,
postage prepaid and addressed to the party to be notified at the address
indicated for such party on the signature page hereof, or at such other address
as such party may designate by ten (10) days' advance written notice to the
other parties.

          3.6   Expenses. If any action at law or in equity is necessary to
                --------
enforce or interpret the terms of this Agreement, the prevailing party shall be
entitled to reasonable attorneys' fees, costs and necessary disbursements in
addition to any other relief to which such party may be entitled.

          3.7   Amendments and Waivers. Any term of this Agreement may be
                ----------------------
amended and the observance of any term of this Agreement may be waived (either
generally or in a particular instance and either retroactively or
prospectively), only with the written consent of the Company and the holders of
a majority of the Registrable Securities then outstanding; provided, however,
that (i) in the event such amendment or waiver adversely affects the rights
and/or obligations of the Management Holders under this Agreement in a different
manner than the other Holders, such amendment or waiver shall also require the
written consent of a majority of the Common Stock held by the Management
Holders, (ii) Section 2.5(a) shall not be amended or waived without the prior
written consent of Xerox, (iii) Section 2.5(b) shall not be amended or waived
without the prior written consent of Apex and (iv) Section 2.5(c) shall not be
amended or waived without the prior written consent of Hewlett-Packard. Any
amendment or waiver effected in accordance with this paragraph shall be binding
upon each holder of any Registrable Securities then outstanding, each future
holder of all such Registrable Securities and the Company.

          3.8   Severability. If one or more provisions of this Agreement are
                ------------
held to be unenforceable under applicable law, such provision shall be excluded
from this Agreement and the balance of the Agreement shall be interpreted as if
such provision were so excluded and shall be enforceable in accordance with its
terms.

          3.9   Aggregation of Stock. All shares of Registrable Securities held
                --------------------
or acquired by affiliated entities or persons shall be aggregated together for
the purpose of determining the availability of any rights under this Agreement.

                                       18
<PAGE>

          3.10  Entire Agreement. This Agreement (including the Exhibits hereto,
                ----------------
if any) constitutes the full and entire understanding and agreement between the
parties with regard to the subjects hereof and thereof.

          3.11  Termination of Prior Agreement. Upon the effectiveness of this
                ------------------------------
Agreement, the Prior Agreement shall terminate and be of no further force and
effect, and shall be superseded and replaced in its entirety by this Agreement.

                                       19
<PAGE>

          IN WITNESS WHEREOF, the parties have executed this Agreement as of the
date first above written.

                              COMPANY:

                              PLACEWARE, INC.

                              By:___________________________________________
                                  Barry James Folsom, President and
                                  Chief Executive Officer

                              Address: 201 Ravendale Drive
                                       Mountain View, CA 94043




                                Signature Page
                  Third Restated Investor's Rights Agreement
<PAGE>

          IN WITNESS WHEREOF, the parties have executed this Agreement as of the
date first above written.

                              INVESTORS:


                              ______________________________________________
                              Print Name

                              By:___________________________________________

                              Name:_________________________________________

                              Title:________________________________________

                      Address:______________________________________________
                              ______________________________________________
                              ______________________________________________


                                Signature Page
                  Third Restated Investor's Rights Agreement
<PAGE>

                                  SCHEDULE A

Investors
---------

BankAmerica Ventures
950 Tower Lane
Suite 700
Foster City, CA 94404
Attn:

Trans Cosmos USA
555 Twin Dolphin Drive
Suite 150
Redwood Shores, CA 94065
Attn: Yasushi Nishida

Gabriel Venture Partners, L.P.
1325 Howard Ave.
Burlingame, CA 94010
Attn: Rick Bolander

Gabriel Legacy Fund, L.P.
1325 Howard Ave.
Burlingame, CA  94010
Attn: Rick Bolander

Hewlett-Packard Company
3000 Hanover Street
Mailstop 20BQ
Palo Alto, CA  94304
Attn: General Counsel

Apex Investment Fund III, L.P.
Suite 9600
233 South Wacker Drive
Chicago, IL 60606

Apex Strategic Partners, LLC
Suite 9600
233 South Wacker Drive
Chicago, IL 60606

InterWest Partners VI, L.P.
3000 Sand Hill Road
Building 3, Suite 255
Menlo Park, CA 94025
Attn: Flip Gianos

                                      A-1
<PAGE>

InterWest Investors VI, L.P.
3000 Sand Hill Road
Building 3, Suite 255
Menlo Park, CA 94025
Attn: Flip Gianos

Bay Partners SBIC, L.P.
10600 North De Anza Blvd., #100
Cupertino, CA 95015

Xerox Corporation
800 Long Ridge Road
P. O. Box 1600
Stamford, CT 06904
Attn: Charles Gilliam

Larry J. Williams and Margaret T. Williams,
Trustees of the Williams Family Trust
U/D/T dated 7/30/91
12 Snecker Ct.
Menlo Park, CA 94025

Magnuson Revocable Trust Dated 1/14/94
c/o Richard P. & Amy C. Magnuson, Trustees
355 Mariposa Avenue
Los Altos, CA 94022

Rekhi Family Trust Dated 12/15/89
c/o Kanwal S. Rekhi & Ann H. Rekhi, Trustees
16150 Hillvale Avenue
Monte Sereno, CA 95030

Raj-Ann Kaur Rekhi Trust Dated 12/15/89
Benjamin Rekhi Trust Dated 12/15/89
c/o Navindra Jain, Kanwal S. Rekhi & Ann H. Rekhi, Trustees
16150 Hillvale Avenue
Monte Sereno, CA 95030

Rekhi Family Trust, Created on June 17, 1992
c/o Upender Jeet Singh Rekhi & Kulvinder Kaur Rekhi, Trustees
18330 Laurel Drive
Los Gatos, CA 95030

                                      A-2
<PAGE>

J.F. Shea Co., Inc. as nominee 1996-48
c/o Edmund Shea
655 Brea Canyon Drive
Walnut, CA 91789

Henry L. B. Wilder
331 Tripp Road
Woodside, CA 94062

Dougery Ventures, LLC
165 Santa Ana Avenue
San Francisco, CA  94127
Attn: John Dougery

Dougery Revocable Trust UTD 10/15/96
John R. Dougery Revocable Trust UTD 10/15/96
Shelley Dougery Trust
John R. Dougery, Jr. Trust
Kathryn Ann Dougery Trust
Rolapp Trust
165 Santa Ana Avenue
San Francisco, CA  94127
Attn: John Dougery

K. B. Chandrasekhar
c/o Exodus Communications, Inc.
2650 San Tomas Expressway
Santa Clara, CA 95051

Ayer Family Trust Dated 6/30/82
William E. Ayer
c/o William E. Ayer
3000 Sand Hill Road, #4-145
Menlo Park, CA 94402

Goel Family Partnership
98 Ridgeview Drive
Atherton, CA 94027

Donald B. Ayer
6250 Park Road
McLean, VA 22101

William S. Ayer
15829 S.E. 56th Place
Bellevue, WA 98006

                                      A-3
<PAGE>

James F. McGill
201 West 72/nd/ Street, #16A
New York, NY 10023

Eric Emerson Schmidt & Wendy Schmidt,
Trustees or successor trustee, under the
Schmidt family living trust u/a/d 2/19/87
366 Walsh Road
Atherton, CA 94027

Daniel C. Lynch
25660 LaLanne Court
Los Altos Hills, CA 94022

George B. and Mary Lou Shott Trust U/A DTD 10/15/91
990 Green Street, #5
San Francisco, CA 94133

Rajinder K. Chopra
Anjali Chopra
19918 Portal Plaza
Cupertino, CA 95014

Rajdak Investment LLC
151 Bridgton Court
Los Altos, CA 94022

Barry James Folsom
27197 Black Mountain Road
Los Altos Hills, CA 94022

Zeisler/Bailey Family Trust,
Dated 5/14/98
c/o John Zeisler
25975 Alicante Lane
Los Altos Hills, CA 94022

Comdisco, Inc.
c/o Comdisco Ventures Division
3000 Sand Hill Road
Building 1, Suite 155
Menlo Park, CA 94025

                                      A-4
<PAGE>

                                  SCHEDULE B

Management Holders
------------------

Richard H. Bruce
1956 Alford Drive
Los Altos, CA 94024-6901

Pavel Curtis
27990 Via Ventana
Los Altos Hills, CA 94022

Michael D. Dixon
1523 Portola Avenue
Palo Alto, CA 94306

Robert T. Krivacic
2302 Gunar Drive
San Jose, CA 95124

David A. Nichols
2555 Dell Avenue
Mountain View, CA 94043

The William W. and Nancy W. Shott
Family Trust Dated May 14, 1993
280 Willowbrook
Portola Valley, CA 94028

Magnuson Revocable Trust Dated 1/14/94
c/o Richard P. & Amy C. Magnuson, Trustees
355 Mariposa Avenue
Los Altos, CA 94022

Rekhi Family Trust Dated 12/15/89
c/o Kanwal S. Rekhi & Ann H. Rekhi, Trustees
16150 Hillvale Avenue
Monte Sereno, CA 95030

                                      B-1