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                                                                     EXHIBIT 4.4

                     ____________________________________

                         RATIONAL SOFTWARE CORPORATION

                                    ISSUER

                                      TO
            STATE STREET BANK AND TRUST COMPANY OF CALIFORNIA, N.A.,

                                    TRUSTEE
                               __________________

                                   INDENTURE

                         Dated as of February 2, 2000

                              ___________________

            5% CONVERTIBLE SUBORDINATED NOTES DUE FEBRUARY 1, 2007

                    _______________________________________
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                         Rational Software Corporation

             5% Convertible Subordinated Notes due February 1, 2007


                         Registration Rights Agreement
                         -----------------------------

                                              February 2, 2000


Goldman, Sachs & Co.,
Credit Suisse First Boston Corporation
Chase Securities Inc.
c/o Goldman, Sachs & Co.
85 Broad Street
New York, New York 10004

Ladies and Gentlemen:

     Rational Software Corporation, a Delaware corporation (the "Company"),
proposes to issue and sell to the Purchasers (as defined herein) upon the terms
set forth in the Purchase Agreement (as defined herein) its 5% Convertible
Subordinated Notes due February 1, 2007 (the "Securities").  As an inducement to
the Purchasers to enter into the Purchase Agreement and in satisfaction of a
condition to the obligations of the Purchasers thereunder, the Company agrees
with the Purchasers for the benefit of Holders (as defined herein) from time to
time of the Registrable Securities (as defined herein) as follows:

     1.   Definitions.

     (a) Capitalized terms used herein without definition shall have the
meanings ascribed to them in the Purchase Agreement.  As used in this Agreement,
the following defined terms shall have the following meanings:

     "Act" or "Securities Act" means the United States Securities Act of 1933,
as amended.

     "Affiliate" of any specified person means any other person which, directly
or indirectly, is in control of, is controlled by, or is under common control
with such specified person.  For purposes of this definition, control of a
person means the power, direct or indirect, to direct or cause the direction of
the management and policies of such person whether by contract or otherwise; and
the terms "controlling" and "controlled" have meanings correlative to the
foregoing.

     "Closing Date" means the First Time of Delivery as defined in the Purchase
Agreement.
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     "Commission" means the United States Securities and Exchange Commission, or
any other federal agency at the time administering the Exchange Act or the
Securities Act, whichever is the relevant statute for the particular purpose.

     "Common Stock" means the Company's common stock, par value $0.01 per share.

     "DTC" means The Depository Trust Company.

     "Effectiveness Period" has the meaning assigned thereto in Section 2(b)(i)
hereof.

     "Effective Time" means the date on which the Commission declares the Shelf
Registration Statement effective or on which the Shelf Registration Statement
otherwise becomes effective.

     "Electing Holder" has the meaning assigned thereto in Section 3(a)(3)
hereof.

     "Exchange Act" means the United States Securities Exchange Act of 1934, as
amended.

     "Holder" means, any person that is the record owner of Registrable
Securities (and includes any person that has a beneficial interest in any
Registrable Security in book-entry form).

     "Indenture" means the Indenture, dated as of February 2, 2000, between the
Company and State Street Bank and Trust Company of California N.A., as amended
and supplemented from time to time in accordance with its terms.

     "Managing Underwriters" means the investment banker or investment bankers
and manager or managers that shall administer an underwritten offering, if any,
conducted pursuant to Section 7 hereof.

     "NASD Rules" means the Rules of the National Association of Securities
Dealers, Inc., as amended from time to time.

     "Notice and Questionnaire" means a Notice of Registration Statement and
Selling Securityholder Questionnaire substantially in the form of Exhibit A
hereto.

     The term "person" means an individual, partnership, corporation, trust or
unincorporated organization, or a government or agency or political subdivision
thereof.

     "Prospectus" means the prospectus (including, without limitation, any
preliminary prospectus, any final prospectus and any prospectus that discloses
information previously omitted from a prospectus filed as part of an effective
registration statement in reliance upon Rule 430A under the Act) included in the
Shelf Registration Statement, as amended or supplemented by any prospectus
supplement with respect to the terms of the offering of any portion of the
Registrable Securities covered by the Shelf Registration Statement and by all
other amendments and supplements to such prospectus, including all material
incorporated by

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reference in such prospectus and all documents filed after the date of such
prospectus by the Company under the Exchange Act and incorporated by reference
therein.

     "Purchase Agreement" means the purchase agreement, dated as of January 27,
2000, between the Purchasers and the Company relating to the Securities.

     "Purchasers" means the Purchasers named in Schedule I to the Purchase
Agreement.

     "Registrable Securities" means all or any portion of the Securities issued
from time to time under the Indenture in registered form and the shares of
Common Stock issuable upon conversion of such Securities; provided, however,
                                                          --------  -------
that a security ceases to be a Registrable Security when it is no longer a
Restricted Security.

     "Restricted Security" means any Security or share of Common Stock issuable
upon conversion thereof except any such Security or share of Common Stock which
(i) has been effectively registered under the Securities Act and sold in a
manner contemplated by the Shelf Registration Statement, (ii) has been
transferred in compliance with Rule 144 under the Securities Act (or any
successor provision thereto) or is transferable pursuant to paragraph (k) of
such Rule 144 (or any successor provision thereto), (iii) has been sold in
compliance with Regulation S under the Securities Act (or any successor thereto)
and does not constitute the unsold allotment of a distributor within the meaning
of Regulation S under the Securities Act, or (iv) has otherwise been transferred
and a new Security or share of Common Stock not subject to transfer restrictions
under the Securities Act has been delivered by or on behalf of the Company in
accordance with Section 3.3 of the Indenture.

     "Rules and Regulations" means the published rules and regulations of the
Commission promulgated under the Securities Act or the Exchange Act, as in
effect at any relevant time.

     "Shelf Registration" means a registration effected pursuant to Section 2
hereof.

     "Shelf Registration Statement" means a "shelf" registration statement filed
under the Securities Act providing for the registration of, and the sale on a
continuous or delayed basis by the Holders of, all of the Registrable Securities
pursuant to Rule 415 under the Securities Act and/or any similar rule that may
be adopted by the Commission, filed by the Company pursuant to the provisions of
Section 2 of this Agreement, including the Prospectus contained therein, any
amendments and supplements to such registration statement, including post-
effective amendments, and all exhibits and all material incorporated by
reference in such registration statement.

     "Trust Indenture Act" means the Trust Indenture Act of 1939, or any
successor thereto, and the rules, regulations and forms promulgated thereunder,
as the same shall be amended from time to time.

     The term "underwriter" means any underwriter of Registrable Securities in
connection with an offering thereof under a Shelf Registration Statement.

                                       3
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     (b)  Wherever there is a reference in this Agreement to a percentage of the
"principal amount" of Registrable Securities or to a percentage of Registrable
Securities, Common Stock shall be treated as representing the principal amount
of Securities which was surrendered for conversion or exchange in order to
receive such number of shares of Common Stock.

     2.   Shelf Registration.

     (a)  The Company shall, no later than 90 calendar days following the
Closing Date, file with the Commission a Shelf Registration Statement relating
to the offer and sale of the Registrable Securities by the Holders from time to
time in accordance with the methods of distribution elected by such Holders and
set forth in such Shelf Registration Statement and, thereafter, shall use its
reasonable efforts to cause such Shelf Registration Statement to be declared
effective under the Act no later than 180 calendar days following the Closing
Date; provided, however, that the Company may, upon written notice to all
Holders, postpone having the Shelf Registration Statement declared effective for
a reasonable period not to exceed 90 days if the Company possesses material non-
public information, the disclosure of which would have a material adverse effect
on the Company and its subsidiaries taken as a whole; provided, further,
however, that no Holder shall be entitled to be named as a selling
securityholder in the Shelf Registration Statement or to use the Prospectus
forming a part thereof for resales of Registrable Securities unless such Holder
is an Electing Holder.

     (b)  The Company shall use its best efforts:

          (i)   To keep the Shelf Registration Statement continuously effective
     in order to permit the Prospectus forming part thereof to be usable by
     Electing Holders, subject to Section 3(d)(v), until the earliest of (1) the
     sale of all Registrable Securities registered under the Shelf Registration
     Statement; (2) the expiration of the period referred to in Rule 144(k) of
     the Act with respect to all Registrable Securities held by Electing Holders
     that are not Affiliates of the Company; and (3) two years from the date
     (the "Effective Date") the Securities are issued (such period being
     referred to herein as the "Effectiveness Period");

          (ii)  After the Effective Time of the Shelf Registration Statement,
     promptly upon the request of any Holder of Registrable Securities that is
     not then an Electing Holder, to take any action reasonably necessary to
     enable such Holder to use the Prospectus forming a part thereof for resales
     of Registrable Securities, including, without limitation, any action
     necessary to identify such Holder as a selling securityholder in the Shelf
     Registration Statement; provided, however, that nothing in this
     subparagraph shall relieve such Holder of the obligation to return a
     completed and signed Notice and Questionnaire to the Company in accordance
     with Section 3(a)(ii) hereof; and

          (iii) If at any time the Securities, pursuant to Article XII of the
     Indenture, are convertible into securities other than Common Stock, the
     Company shall, or shall cause any successor under the Indenture to, cause
     such securities to be included in the Shelf

                                       4
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     Registration Statement no later than the date on which the Securities may
     then be convertible into such securities.

The Company shall be deemed not to have used its reasonable efforts to keep the
Shelf Registration Statement effective during the requisite period if the
Company voluntarily takes any action that would result in Holders of Registrable
Securities covered thereby not being able to offer and sell any of such
Registrable Securities during that period, unless such action is required by
applicable law and the Company thereafter promptly complies with the
requirements of paragraph 3(j) below.

     (c) The Company may suspend the use of the Prospectus for a period not to
exceed 45 days in any 90-day period or an aggregate of 90 days in any 12-month
period if the Board of Directors of the Company shall have determined in good
faith that because of valid business reasons (not including avoidance of the
Company's obligations hereunder), including the acquisition or divestiture of
assets, pending corporate developments and similar events, it is in the best
interests of the Company to suspend such use, and prior to suspending such use
the Company provides the Holders with written notice of such suspension, which
notice need not specify the nature of the event giving rise to such suspension.

     3.   Registration Procedures.  In connection with the Shelf Registration
Statement, the following provisions shall apply:

     (a) (i)   Not less than 30 calendar days prior to the time the Company
intends in good faith to have the Shelf Registration Statement declared
effective, the Company shall mail the Notice and Questionnaire to the Holders of
Registrable Securities.  No Holder shall be entitled to be named as a selling
securityholder in the Shelf Registration Statement as of the Effective Time, and
no Holder shall be entitled to use the Prospectus forming a part thereof for
resales of Registrable Securities at any time, unless such Holder has returned a
completed and signed Notice and Questionnaire to the Company by the deadline for
response set forth therein; provided, however, Holders of Registrable Securities
shall have at least 28 calendar days from the date on which the Notice and
Questionnaire is first mailed to such Holders to return a completed and signed
Notice and Questionnaire to the Company.

         (ii)  After the Effective Time of the Shelf Registration Statement, the
     Company shall, upon the request of any Holder of Registrable Securities
     that is not then an Electing Holder, promptly send a Notice and
     Questionnaire to such Holder.  The Company shall not be required to take
     any action to name such Holder as a selling securityholder in the Shelf
     Registration Statement or to enable such Holder to use the Prospectus
     forming a part thereof for resales of Registrable Securities until such
     Holder has returned a completed and signed Notice and Questionnaire to the
     Company.

         (iii) The term "Electing Holder" shall mean any Holder of Registrable
     Securities that has returned a completed and signed Notice and
     Questionnaire to the Company in accordance with Section 3(a)(i) or 3(a)(ii)
     hereof.

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<PAGE>

     (b)  The Company shall furnish to each Holder who has made an election
pursuant to Section 3(a)(i), prior to the Effective Time, a copy of the Shelf
Registration Statement initially filed with the Commission, and shall furnish to
such Holders, prior to the filing thereof with the Commission, copies of each
amendment thereto and each amendment or supplement, if any, to the Prospectus
included therein, and shall use its reasonable efforts to reflect in each such
document, at the Effective Time or when so filed with the Commission, as the
case may be, such  comments as such Holders and their respective counsel
reasonably may propose.

     (c)  The Company shall promptly take such action as may be necessary so
that (i) each of the Shelf Registration Statement and any amendment thereto and
the Prospectus forming part thereof and any amendment or supplement thereto (and
each report or other document incorporated therein by reference in each case)
complies in all material respects with the Securities Act and the Exchange Act
and the respective rules and regulations thereunder, (ii) each of the Shelf
Registration Statement and any amendment thereto does not, when it becomes
effective, contain an untrue statement of a material fact or omit to state a
material fact required to be stated therein or necessary to make the statements
therein not misleading and (iii) each of the Prospectus forming part of the
Shelf Registration Statement, and any amendment or supplement to such
Prospectus, does not during the Effectiveness Period include an untrue statement
of a material fact or omit to state a material fact necessary in order to make
the statements therein, in the light of the circumstances under which they were
made, not misleading.

     (d)  The Company shall promptly advise each Electing Holder, and shall
confirm such advice in writing if so requested by any such Holder:

          (i)   when a Shelf Registration Statement and any amendment thereto
     has been filed with the Commission and when a Shelf Registration Statement
     or any post-effective amendment thereto has become effective, in each case
     making a public announcement thereof by release made to Reuters Economic
     Services and Bloomberg Business News;

          (ii)  of any request by the Commission for amendments or supplements
     to the Shelf Registration Statement or the Prospectus included therein or
     for additional information.

          (iii) of the issuance by the Commission of any stop order suspending
     the effectiveness of the Shelf Registration Statement or the initiation of
     any proceedings for such purpose;

     (iv) of the receipt by the Company of any notification with respect to
     the suspension of the qualification of the securities included in the Shelf
     Registration Statement for sale in any jurisdiction or the initiation of
     any proceeding for such purpose; and

     (v)  of the happening of any event or the existence of any state of
     facts that requires

                                       6
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     the making of any changes in the Shelf Registration Statement or the
     Prospectus included therein so that, as of such date, such Shelf
     Registration Statement and Prospectus do not contain an untrue statement of
     a material fact and do not omit to state a material fact required to be
     stated therein or necessary to make the statements therein (in the case of
     the Prospectus, in light of the circumstances under which they were made)
     not misleading (which advice shall be accompanied by an instruction to such
     Holders to suspend the use of the Prospectus until the requisite changes
     have been made).

     (e) The Company shall use its best efforts to prevent the issuance, and if
issued to obtain the withdrawal, of any order suspending the effectiveness of
the Shelf Registration Statement at the earliest possible time.

     (f) The Company shall furnish to each Electing Holder, without charge, at
least one copy of the Shelf Registration Statement and all post-effective
amendments thereto, including financial statements and schedules, and, if such
Holder so requests in writing, all reports, other documents and exhibits that
are filed with or incorporated by reference in the Shelf Registration Statement.

     (g) The Company shall, during the Effectiveness Period, deliver to each
Electing Holder, without charge, as many copies of the Prospectus (including
each preliminary Prospectus) included in the Shelf Registration Statement and
any amendment or supplement thereto as such Electing Holder may reasonably
request; and the Company consents (except during the continuance of any event
described in Section 3(d)(v) above) to the use of the Prospectus and any
amendment or supplement thereto by each of the Electing Holders in connection
with the offering and sale of the Registrable Securities covered by the
Prospectus and any amendment or supplement thereto during the Effectiveness
Period.

     (h) Prior to any offering of Registrable Securities pursuant to the Shelf
Registration Statement, the Company shall (i) register or qualify or cooperate
with the Electing Holders and their respective counsel in connection with the
registration or qualification of such Registrable Securities for offer and sale
under the securities or "blue sky" laws of such jurisdictions within the United
States as any Electing Holder may reasonably request, (ii) keep such
registrations or qualifications in effect and comply with such laws so as to
permit the continuance of offers and sales in such jurisdictions for so long as
may be necessary to enable any Electing Holder or underwriter, if any, to
complete its distribution of Registrable Securities pursuant to the Shelf
Registration Statement, and (iii) take any and all other actions necessary or
advisable to enable the  disposition in such jurisdictions of such Registrable
Securities; provided, however, that in no event shall the Company be obligated
to (A) qualify as a foreign corporation or as a dealer in securities in any
jurisdiction where it would not otherwise be required to so qualify but for this
Section 3(h) or (B) file any general consent to service of process in any
jurisdiction where it is not as of the date hereof so subject.

     (i) Unless any Registrable Securities shall be in book-entry only form, the
Company shall cooperate with the Electing Holders to facilitate the timely
preparation and delivery of certificates representing Registrable Securities to
be sold pursuant to the Shelf Registration

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Statement, which certificates, if so required by any securities exchange upon
which any Registrable Securities are listed, shall be penned, lithographed or
engraved, or produced by any combination of such methods, on steel engraved
borders, and which certificates shall be free of any restrictive legends and in
such permitted denominations and registered in such names as Electing Holders
may request in connection with the sale of Registrable Securities pursuant to
the Shelf Registration Statement.

     (j) Upon the occurrence of any fact or event contemplated by paragraph
3(d)(v) above, the Company shall promptly prepare a post-effective amendment to
any Shelf Registration Statement or an amendment or supplement to the related
Prospectus or file any other required document so that, as thereafter delivered
to purchasers of the Registrable Securities included therein, the Prospectus
will not include an untrue statement of a material fact or omit to state any
material fact necessary to make the statements therein, in the light of the
circumstances under which they were made, not misleading.  If the Company
notifies the Electing Holders of the occurrence of any event contemplated by
paragraph 3(d)(v) above, the Electing Holder shall suspend the use of the
Prospectus until the requisite changes to the Prospectus have been made.

     (k) Not later than the Effective Time of the Shelf Registration Statement,
the Company shall provide a CUSIP number for the Registrable Securities that are
debt securities.

     (l) The Company shall use its best efforts to comply with all applicable
Rules and Regulations, and to make generally available to its securityholders as
soon as practicable, but in any event not later than eighteen months after (i)
the effective date (as defined in Rule 158(c) under the Securities Act) of the
Shelf Registration Statement, (ii) the effective date of each post-effective
amendment to the Shelf Registration Statement, and (iii) the date of each filing
by the Company with the Commission of an Annual Report on Form 10-K that is
incorporated by reference in the Shelf Registration Statement, an earning
statement of the Company and its subsidiaries complying with Section 11(a) of
the Securities Act and the rules and regulations of the Commission thereunder
(including, at the option of the Company, Rule 158).

     (m) Not later than the Effective Time of the Shelf Registration Statement,
the Company shall cause the Indenture to be qualified under the Trust Indenture
Act; in connection with such qualification, the Company shall cooperate with the
Trustee under the Indenture and the Holders (as defined in the Indenture) to
effect such changes to the Indenture as may be required for such Indenture to be
so qualified in accordance with the terms of the Trust Indenture Act; and the
Company shall execute, and shall use all reasonable efforts to cause the Trustee
to execute, all documents that may be required to effect such changes and all
other forms and documents required to be filed with the Commission to enable
such Indenture to be so qualified in a timely manner.  In the event that any
such amendment or modification referred to in this Section 3(m) involves the
appointment of a new trustee under the Indenture, the Company shall appoint a
new trustee thereunder pursuant to the applicable provisions of the Indenture.

     (n) In the event of an underwritten offering conducted pursuant to Section
6 hereof, the Company shall, if requested, promptly include or incorporate in a
Prospectus supplement or

                                       8
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post-effective amendment to the Shelf Registration Statement such information as
the Managing Underwriters reasonably agree should be included therein and to
which the Company does not reasonably object and shall make all required filings
of such Prospectus supplement or post-effective amendment as soon as practicable
after it is notified of the matters to be included or incorporated in such
Prospectus supplement or post-effective amendment.

     (o)    The Company shall enter into such customary agreements (including an
underwriting agreement in customary form in the event of an underwritten
offering conducted pursuant to Section 6 hereof) and take all other appropriate
action in order to expedite and facilitate the registration and disposition of
the Registrable Securities, and in connection therewith, if an underwriting
agreement is entered into, cause the same to contain indemnification provisions
and procedures substantially identical to those set forth in Section 5 hereof
with respect to all parties to be indemnified pursuant to Section 5 hereof.

     (p)    The Company shall:

     (i)(A) make reasonably available for inspection by Electing Holders,
     any underwriter participating in any disposition pursuant to the Shelf
     Registration Statement, and any attorney, accountant or other agent
     retained by such Holders or any such underwriter all relevant financial and
     other records, pertinent corporate documents and properties of the Company
     and its subsidiaries, and (B) cause the Company's officers, directors and
     employees to supply all information reasonably requested by such Holders or
     any such underwriter, attorney, accountant or agent in connection with the
     Shelf Registration Statement, in each case, as is customary for similar due
     diligence examinations; provided, however, that all records, information
     and documents that are designated in writing by the Company, in good faith,
     as confidential shall be kept confidential by such Holders and any such
     underwriter, attorney, accountant or agent, unless such disclosure is made
     in connection with a court proceeding or required by law, or such records,
     information or documents become available to the public generally or
     through a third party without an accompanying obligation of
     confidentiality; and provided further that, if the foregoing inspection and
     information gathering would otherwise disrupt the Company's conduct of its
     business, such inspection and information gathering shall, to the greatest
     extent possible, be coordinated on behalf of the Electing Holders and the
     other parties entitled thereto by one counsel designated by and on behalf
     of Electing Holders and other parties; in the event that any Holder,
     underwriter, attorney, accountant or agent is required to disclose
     confidential information of the Company by law or in a court proceeding,
     such Holder, underwriter, attorney, accountant or agent will provide the
     Company with notice of such disclosure requirement and copies of the
     information to be disclosed, if possible, and will cooperate with the
     Company, to the extent reasonably practicable, to limit such disclosure;

        (ii) in connection with any underwritten offering conducted pursuant
     to Section 6 hereof, make such representations and warranties to the
     Holders participating in such underwritten offering and to the Managing
     Underwriters, in form, substance and scope as are customarily made by the
     Company to underwriters in primary underwritten

                                       9
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     offerings of equity and convertible debt securities and covering matters
     including, but not limited to, those set forth in the Purchase Agreement;

          (iii) in connection with any underwritten offering conducted pursuant
     to Section 6 hereof, obtain opinions of counsel to the Company (which
     counsel and opinions (in form, scope and substance) shall be reasonably
     satisfactory to the Managing Underwriters) addressed to each Holder
     participating in such underwritten offering and the underwriters, covering
     such matters as are customarily covered in opinions requested in primary
     underwritten offerings of equity and convertible debt securities and such
     other matters as may be reasonably requested by such Holders and
     underwriters (it being agreed that the matters to be covered by such
     opinions shall include, without limitation, as of the date of the opinion
     and as of the Effective Time of the Shelf Registration Statement or most
     recent post-effective amendment thereto, as the case may be, the absence
     from the Shelf Registration Statement and the Prospectus, including the
     documents incorporated by reference therein, of an untrue statement of a
     material fact or the omission of a material fact required to be stated
     therein or necessary to make the statements therein not misleading;

          (iv)  in connection with any underwritten offering conducted pursuant
     to Section 6 hereof, obtain "cold comfort" letters and updates thereof from
     the independent public accountants of the Company (and, if necessary, from
     the independent public accountants of any subsidiary of the Company or of
     any business acquired by the Company for which financial statements and
     financial data are, or are required to be, included in the Shelf
     Registration Statement), addressed to each Holder participating in such
     underwritten offering (if such Holder has provided such letter,
     representations or documentation, if any, required for such cold comfort
     letter to be so addressed) and the underwriters, in customary form and
     covering matters of the type customarily covered in "cold comfort" letters
     in connection with primary underwritten offerings;

          (v)   in connection with any underwritten offering conducted pursuant
     to Section 6 hereof, deliver such documents and certificates as may be
     reasonably requested by any Holders participating in such underwritten
     offering and the Managing Underwriters, if any, including, without
     limitation, certificates to evidence compliance with Section 3(j) hereof
     and with any conditions contained in the underwriting agreement or other
     agreements entered into by the Company.

     (q)  The Company will use its reasonable efforts to cause the Common Stock
issuable upon conversion of the Securities to be listed for quotation on the
National Association of Securities Dealers Automated Quotations National Market
System or other stock exchange or trading system on which the Common Stock
primarily trades on or prior to the Effective Time of the Shelf Registration
Statement hereunder.

     (r)  In the event that any broker-dealer registered under the Exchange Act
shall be an "affiliate" (as defined in Rule 2720(b)(1) of the NASD Rules (or any
successor provision thereto)) of the Company or has a "conflict of interest" (as
defined in Rule 2720(b)(7) of the NASD Rules (or any successor provision
thereto)) and such broker-dealer shall underwrite,

                                       10
<PAGE>

participate as a member of an underwriting syndicate or selling group or assist
in the distribution of any Registrable Securities covered by the Shelf
Registration Statement, whether as a Holder of such Registrable Securities or as
an underwriter, a placement or sales agent or a broker or dealer in respect
thereof, or otherwise, the Company shall assist such broker-dealer in complying
with the requirements of the NASD Rules, including, without limitation, by (A)
engaging a "qualified independent underwriter" (as defined in Rule 2720(b)(15)
of the NASD Rules (or any successor provision thereto)) to participate in the
preparation of the registration statement relating to such Registrable
Securities, to exercise usual standards of due diligence in respect thereto and
to recommend the public offering price of such Registrable Securities, (B)
indemnifying such qualified independent underwriter to the extent of the
indemnification of underwriters provided in Section 5 hereof, and (C) providing
such information to such broker-dealer as may be required in order for such
broker-dealer to comply with the requirements of the NASD Rules.

     (s) The Company shall use its best efforts to take all other steps
necessary to effect the registration, offering and sale of the Registrable
Securities covered by the Shelf Registration Statement contemplated hereby.

     4.  Registration Expenses.  Except as otherwise provided in Section 3, the
Company shall bear all fees and expenses incurred in connection with the
performance of its obligations under Sections 2 and 3 hereof and shall bear or
reimburse the Electing Holders for the reasonable fees and disbursements of a
single counsel selected by a plurality of all Electing Holders who own an
aggregate of not less than 25% of the Registrable Securities covered by the
Shelf Registration Statement to act as counsel therefore in connection
therewith.  Each Electing Holder shall pay all underwriting discounts and
commissions and transfer taxes, if any, relating to the sale or disposition of
such Electing Holder's Registrable Securities pursuant to the Shelf Registration
Statement.

     5.  Indemnification and Contribution.

     (a) Indemnification by the Company. Upon the registration of the
Registrable Securities pursuant to Section 2 hereof, the Company shall indemnify
and hold harmless each Electing Holder and each underwriter, selling agent or
other securities professional, if any, which facilitates the disposition of
Registrable Securities, and each of their respective officers and directors and
each person who controls such Electing Holder, underwriter, selling agent or
other securities professional within the meaning of Section 15 of the Securities
Act or Section 20 of the Exchange Act (each such person being sometimes referred
to as an "Indemnified Person") against any losses, claims, damages or
liabilities, joint or several, to which such Indemnified Person may become
subject under the Securities Act or otherwise, insofar as such losses, claims,
damages or liabilities (or actions in respect thereof) arise out of or are based
upon an untrue statement or alleged untrue statement of a material fact
contained in any Shelf Registration Statement under which such Registrable
Securities are to be registered under the Securities Act, or any Prospectus
contained therein or furnished by the Company to any Indemnified Person, or any
amendment or supplement thereto, or arise out of or are based upon 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, and the
Company hereby

                                       11
<PAGE>

agrees to reimburse such Indemnified Person for any legal or other expenses
reasonably incurred by them in connection with investigating or defending any
such action or claim as such expenses are incurred; provided, however, that the
Company shall not be liable to any such Indemnified Person in any such case to
the extent that any such loss, claim, damage or liability arises out of or is
based upon an untrue statement or alleged untrue statement or omission or
alleged omission made in such Shelf Registration Statement or Prospectus, or
amendment or supplement, in reliance upon and in conformity with written
information furnished to the Company by such Indemnified Person expressly for
use therein.

     (b) Indemnification by the Holders and any Agents and Underwriters.  Each
Electing Holder agrees, as a consequence of the inclusion of any of such
Holder's Registrable Securities in such Shelf Registration Statement, and each
underwriter, selling agent or other securities professional, if any, which
facilitates the disposition of Registrable Securities shall agree, as a
consequence of facilitating such disposition of Registrable Securities,
severally and not jointly, to (i) indemnify and hold harmless the Company, its
directors, officers who sign any Shelf Registration Statement and each person,
if any, who controls the Company within the meaning of either Section 15 of the
Securities Act or Section 20 of the Exchange Act, against any losses, claims,
damages or liabilities to which the Company or such other persons may become
subject, under the Securities Act or otherwise, insofar as such losses, claims,
damages or liabilities (or actions in respect thereof) arise out of or are based
upon an untrue statement or alleged untrue statement of a material fact
contained in such Shelf Registration Statement or Prospectus, or any amendment
or supplement, or arise out of or are based upon 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, in each case to the
extent, but only to the extent, that such untrue statement or alleged untrue
statement or omission or alleged omission was made in reliance upon and in
conformity with written information furnished to the Company by such Holder,
underwriter, selling agent or other securities professional expressly for use
therein, and (ii) reimburse the Company for any legal or other expenses
reasonably incurred by the Company in connection with investigating or defending
any such action or claim as such expenses are incurred.

     (c) Notices of Claims, Etc.  Promptly after receipt by an indemnified party
under subsection (a) or (b) above of notice of the commencement of any action,
such indemnified party shall, if a claim in respect thereof is to be made
against an indemnifying party under this Section 5, notify such indemnifying
party in writing of the commencement thereof; but the omission so to notify the
indemnifying party shall not relieve it from any liability which it may have to
any indemnified party otherwise than under this Section 5.  In case any such
action shall be brought against any indemnified party and it shall notify an
indemnifying party of the commencement thereof, such indemnifying party shall be
entitled to participate therein and, to the extent that it shall wish, jointly
with any other indemnifying party similarly notified, to assume the defense
thereof, with counsel satisfactory to such indemnified party (who shall not,
except with the consent of the indemnified party, be counsel to the indemnifying
party), and, after notice from the indemnifying party to such indemnified party
of its election so to assume the defense thereof, such indemnifying party shall
not be liable to such indemnified party under this Section 5 for any legal
expenses of other counsel or any other expenses, in each case

                                       12
<PAGE>

subsequently incurred by such indemnified party, in connection with the defense
thereof other than reasonable costs of investigation. No indemnifying party
shall, without the written consent of the indemnified party, effect the
settlement or compromise of, or consent to the entry of any judgment with
respect to, any pending or threatened action or claim in respect of which
indemnification or contribution may be sought hereunder (whether or not the
indemnified party is an actual or potential party to such action or claim)
unless such settlement, compromise or judgment (i) includes an unconditional
release of the indemnified party from all liability arising out of such action
or claim and (ii) does not include a statement as to, or an admission of, fault,
culpability or a failure to act, by or on behalf of any indemnified party.

     (d) Contribution.  If the indemnification provided for in this Section 5 is
unavailable to or insufficient to hold harmless an indemnified party under
subsection (a) or (b) above in respect of any losses, claims, damages or
liabilities (or actions in respect thereof) referred to therein, then each
indemnifying party shall contribute to the amount paid or payable by such
indemnified party as a result of such losses, claims, damages or liabilities (or
actions in respect thereof) in such proportion as is appropriate to reflect the
relative fault of the indemnifying party and the indemnified party in connection
with the statements or omissions which resulted in such losses, claims, damages
or liabilities (or actions in respect thereof), as well as any other relevant
equitable considerations.  The relative fault of such indemnifying party and
indemnified party shall be determined by reference to, among other things,
whether the untrue or alleged untrue statement of a material fact or omission or
alleged omission to state a material fact relates to information supplied by
such indemnifying party or by such indemnified party, and the parties' relative
intent, knowledge, access to information and opportunity to correct or prevent
such statement or omission.  The parties hereto agree that it would not be just
and equitable if contribution pursuant to this Section 5(d) were determined by
pro rata allocation (even if the Electing Holders or any underwriters, selling
agents or other securities professionals or all of them were treated as one
entity for such purpose) or by any other method of allocation which does not
take account of the equitable considerations referred to in this Section 5(d).
The amount paid or payable by an indemnified party as a result of the losses,
claims, damages or liabilities (or actions in respect thereof) referred to above
shall be deemed to include any legal or other fees or expenses reasonably
incurred by such indemnified party in connection with investigating or defending
any such action or claim.  No person guilty of fraudulent misrepresentation
(within the meaning of Section 11(f) of the Securities Act) shall be entitled to
contribution from any person who was not guilty of such fraudulent
misrepresentation.  The obligations of the Electing Holders and any
underwriters, selling agents or other securities professionals in this Section
5(d) to contribute shall be several in proportion to the percentage of principal
amount of Registrable Securities registered or underwritten, as the case may be,
by them and not joint.

     (e) Notwithstanding any other provision of this Section 5, in no event will
any (i) Electing Holder be required to undertake liability to any person under
this Section 5 for any amounts in excess of the dollar amount of the proceeds to
be received by such Holder from the sale of such Holder's Registrable Securities
(after deducting any fees, discounts and commissions applicable thereto)
pursuant to any Shelf Registration Statement under which such Registrable
Securities are to be registered under the Securities Act and (ii) underwriter,

                                       13
<PAGE>

selling agent or other securities professional be required to undertake
liability to any person hereunder for any amounts in excess of the discount,
commission or other compensation payable to such underwriter, selling agent or
other securities professional with respect to the Registrable Securities
underwritten by it and distributed to the public.

     (f) The obligations of the Company under this Section 5 shall be in
addition to any liability which the Company may otherwise have to any
Indemnified Person and the obligations of any Indemnified Person under this
Section 5 shall be in addition to any liability which such Indemnified Person
may otherwise have to the Company.  The remedies provided in this Section 5 are
not exclusive and shall not limit any rights or remedies which may otherwise be
available to an indemnified party at law or in equity.

     6.  Underwritten Offering.  Any Holder of Registrable Securities who
desires to do so may sell Registrable Securities (in whole or in part) in an
underwritten offering; provided that  (i) the Electing Holders of at least 33-
1/3% in aggregate principal amount of the Registrable Securities then covered by
the Shelf Registration Statement shall request such an offering and (ii) at
least such aggregate principal amount of such Registrable Securities shall be
included in such offering; and provided further that the Company shall not be
obligated to cooperate with more than one underwritten offering during the
Effectiveness Period.  Upon receipt of such a request, the Company shall provide
all Holders of Registrable Securities written notice of the request, which
notice shall inform such Holders that they have the opportunity to participate
in the offering.  In any such underwritten offering, the investment banker or
bankers and manager or managers that will administer the offering will be
selected by, and the underwriting arrangements with respect thereto (including
the size of the offering) will be approved by, the holders of a majority of the
Registrable Securities to be included in such offering; provided, however, that
such investment bankers and managers and underwriting arrangements must be
reasonably satisfactory to the Company.  No Holder may participate in any
underwritten offering contemplated hereby unless (a) such Holder agrees to sell
such Holder's Registrable Securities to be included in the underwritten offering
in accordance with any approved underwriting arrangements, (b) such Holder
completes and executes all reasonable questionnaires, powers of attorney,
indemnities, underwriting agreements, lock-up letters and other documents
required under the terms of such approved underwriting arrangements, and (c) if
such Holder is not then an Electing Holder, such Holder returns a completed and
signed Notice and Questionnaire to the Company in accordance with Section
3(a)(2) hereof within a reasonable amount of time before such underwritten
offering.  The Holders participating in any underwritten offering shall be
responsible for any underwriting discounts and commissions and fees and, subject
to Section 4 hereof, expenses of their own counsel.  The Company shall pay all
expenses customarily borne by issuers, including but not limited to filing fees,
the fees and disbursements of its counsel and independent public accountants and
any printing expenses incurred in connection with such underwritten offering.
Notwithstanding the foregoing or the provisions of Section 3(n) hereof, upon
receipt of a request from the Managing Underwriter or a representative of
holders of a majority of the Registrable Securities to be included in an
underwritten offering to prepare and file an amendment or supplement to the
Shelf Registration Statement and Prospectus in connection with an underwritten
offering, the Company may delay the filing of any such amendment or supplement
for up to 90 days if the Board of Directors of

                                       14
<PAGE>

the Company shall have determined in good faith that the Company has a bona fide
business reason for such delay.

     7.   Liquidated Damages.

     (a)  Pursuant to Section 2(a) hereof, the Company may, upon written notice
to all the Holders, postpone having the Shelf Registration Statement declared
effective for a reasonable period not to exceed 90 days if the Company possesses
material non-public information, the disclosure of which would have a material
adverse effect on the Company and its subsidiaries taken as a whole.
Notwithstanding any such postponement, if (i) on or prior to the 90th day
following the Closing Date, a Shelf Registration Statement has not been filed
with the Commission or (ii) on or prior to the 180th day following the Closing
Date, such Shelf Registration Statement is not declared effective by the
Commission (each, a "Registration Default"), the Company shall be required to
pay liquidated damages ("Liquidated Damages"), from and including the day
following such Registration Default until such Shelf Registration Statement is
either so filed or so filed and subsequently declared effective, as applicable,
at a rate per annum equal to an additional one-quarter of one percent (0.25%) of
the principal amount of Registrable Securities, to and including the 90th day
following such Registration Default and one-half of one percent (0.5%) thereof
from and after the 91st day following such Registration Default.

     (b)  In the event that the Shelf Registration Statement ceases to be
effective (or the Holders of Registrable Securities are otherwise prevented or
restricted by the Company from effecting sales pursuant thereto) (an "Effective
Failure") for more than 45 days, whether or not consecutive, in any 90-day
period, or more than 90 days, whether or not consecutive, during any 12-month
period, then the Company shall pay Liquidated Damages at a rate per annum equal
to an additional one-half of one percent (0.5%) from the 46th day of the
applicable 90-day period or the 91st day of the applicable 12-month period, as
the case may be, that such Shelf Registration Statement ceases to be effective
(or the Holders of Registrable Securities are otherwise prevented or restricted
by the Company from effecting sales pursuant thereto) until the earlier of (i)
the time the Shelf Registration Statement again becomes effective or the Holders
of Registrable Securities are again able to make sales under the Shelf
Registration Statement or (2) the time the Effectiveness Period expires. For the
purpose of determining an Effective Failure, days on which the Company has been
obligated to pay Liquidated Damages in accordance with the foregoing in respect
of a prior Effective Failure within the applicable 90-day or 12-month period, as
the case may be, shall not be included.

     (c)  In the event the Company fails to file a post-effective amendment to
the Shelf Registration Statement, or the post-effective amendment is not
declared effective, within the periods required by Section 3, the Company shall
pay Liquidated Damages at a rate per annum equal to an additional one-half of
one percent (0.5%) from and including the date of such Registration Default
until such time as such Registration Default is cured.

     (d)  Any amounts to be paid as Liquidated Damages pursuant to paragraphs
(a), (b) or (c) of this Section 7 shall be paid semi-annually in arrears, with
the first semi-annual payment due on the first Interest Payment Date (as defined
in the Indenture), as applicable, following the

                                       15
<PAGE>

date of such Registration Default. Such Liquidated Damages will accrue (1) in
respect of the Securities at the rates set forth in paragraphs (a), (b) or (c)
of this Section 7, as applicable, on the principal amount of the Securities and
(2) in respect of the Common Stock issued upon conversion of the Securities, at
the rates set forth in paragraphs (a), (b) or (c) of this Section 7, as
applicable, applied to the Conversion Price (as defined in the Indenture) at
that time.

     (e) Except as provided in Section 8(b) hereof, the Liquidated Damages as
set forth in this Section 7 shall be the exclusive monetary remedy available to
the Holders of Registrable Securities for such Registration Default or Effective
Failure. In no event shall the Company be required to pay Liquidated Damages in
excess of the applicable maximum amount of one-half of one percent (0.5%) set
forth above, regardless of whether one or multiple Registration Defaults exist.

     8.  Miscellaneous.

     (a) Other Registration Rights.  The Company may grant registration rights
that would permit any Person that is a third party the right to piggy-back on
any Shelf Registration  Statement, provided that if the Managing Underwriter of
any underwritten offering conducted pursuant to Section 6 hereof notifies the
Company and the Electing Holders that the total amount of securities which the
Electing Holders and the holders of such piggy-back rights intend to include in
any Shelf Registration Statement is so large as to materially threaten the
success of such offering (including the price at which such securities can be
sold), then the amount, number or kind of securities to be offered for the
account of holders of such piggy-back rights will be reduced to the extent
necessary to reduce the total amount of securities to be included in such
offering to the amount, number and kind recommended by the Managing Underwriter
prior to any reduction in the amount of Registrable Securities to be included in
such Shelf Registration Statement.

     (b) Specific Performance.  The parties hereto acknowledge that there would
be no adequate remedy at law if the Company fails to perform any of its
obligations hereunder and that the Purchasers and the Holders from time to time
may be irreparably harmed by any such failure, and accordingly agree that the
Purchasers and such Holders, in addition to any other remedy to which they may
be entitled at law or in equity and without limiting the remedies available to
the Electing Holders under Section 7 hereof, shall be entitled to compel
specific performance of the obligations of the Company under this Registration
Rights Agreement in accordance with the terms and conditions of this
Registration Rights Agreement, in any court of the United States or any State
thereof having jurisdiction.

     (c) Amendments and Waivers.  This Agreement, including this Section 8(c),
may be amended, and waivers or consents to departures from the provisions hereof
may be given, only by a written instrument duly executed by the Company and the
holders of a majority in aggregate principal amount of Registrable Securities
then outstanding.  Each Holder of Registrable Securities outstanding at the time
of any such amendment, waiver or consent or thereafter shall be bound by any
amendment, waiver or consent effected pursuant to this

                                       16
<PAGE>

Section 8(c), whether or not any notice, writing or marking indicating such
amendment, waiver or consent appears on the Registrable Securities or is
delivered to such Holder.

     (d) Notices.  All notices and other communications provided for or
permitted hereunder shall be given as provided in the Indenture.

     (e) Parties in Interest.  The parties to this Agreement intend that all
Holders of Registrable Securities shall be entitled to receive the benefits of
this Agreement and that any Electing Holder shall be bound by the terms and
provisions of this Agreement by reason of such election with respect to the
Registrable Securities which are included in a Shelf Registration Statement.
All the terms and provisions of this Agreement shall be binding upon, shall
inure to the benefit of and shall be enforceable by the respective successors
and assigns of the parties hereto and any Holder from time to time of the
Registrable Securities to the aforesaid extent.  In the event that any
transferee of any Holder of Registrable Securities shall acquire Registrable
Securities, in any manner, whether by gift, bequest, purchase, operation of law
or otherwise, such transferee shall, without any further writing or action of
any kind, be entitled to receive the benefits of and, if an Electing Holder, be
conclusively deemed to have agreed to be bound by and to perform all of the
terms and provisions of this Agreement to the aforesaid extent.

     (f) Counterparts.  This Agreement may be executed in any number of
counterparts and by the parties hereto in separate counterparts, each of which
when so executed shall be deemed to be an original and all of which taken
together shall constitute one and the same agreement.

     (g) Headings.  The headings in this agreement are for convenience of
reference only and shall not limit or otherwise affect the meaning hereof.

     (h) Governing Law.  This Agreement shall be governed by and construed in
accordance with the laws of the State of New York.

     (i) Severability.  In the event that any one or more of the provisions
contained herein, or the application thereof in any circumstances, is held
invalid, illegal or unenforceable in any respect for any reason, the validity,
legality and enforceability of any such provision in every other respect and of
the remaining provisions hereof shall not be in any way impaired or affected
thereby, it being intended that all of the rights and privileges of the parties
hereto shall be enforceable to the fullest extent permitted by law.

     (j) Survival.  The respective indemnities, agreements, representations,
warranties and other provisions set forth in this Agreement or made pursuant
hereto shall remain in full force and effect, regardless of any investigation
(or any statement as to the results thereof) made by or on behalf of any
Electing Holder, any director, officer or partner of such Holder, any agent or
underwriter, any director, officer or partner of such agent or underwriter, or
any controlling person of any of the foregoing, and shall survive the transfer
and registration of the Registrable Securities of such Holder.

                                       17
<PAGE>

     Please confirm that the foregoing correctly sets forth the agreement
between the Company and you.

                                    Very truly yours,


                                    Rational Software Corporation


                                    By: ____________________________
                                        Name:
                                        Title:


Accepted as of the date hereof:
Goldman, Sachs & Co.
Credit Suisse First Boston Corporation
Chase Securities Inc.


By:  _________________________________
         (Goldman, Sachs & Co.)

   On behalf of each of the Purchasers

                                       18
<PAGE>

                                                                       Exhibit A


                         Rational Software Corporation

                       Notice of Registration Statement
                                      and
                     Selling Securityholder Questionnaire
                                     (Date)


     Rational Software Corporation (the "Company") has filed or intends
shortly to file with the United States Securities and Exchange Commission (the
"Commission") a preliminary registration statement on Form S-3 (the "Shelf
Registration Statement") for the registration and resale under the United
States Securities Act of 1933, as amended (the "Securities Act"), of the
Company's 5% Convertible Subordinated Notes due February 1, 2007 (CUSIP No.
75409PAA1) (the "Notes"), and Common Stock issuable upon conversion thereof,
in accordance with the terms of the Registration Rights Agreement, dated as of
February 2, 2000 (the "Registration Rights Agreement") between the Company and
the purchasers named therein (the "Purchasers"). A copy of the Registration
Rights Agreement is attached hereto. All capitalized terms not otherwise defined
herein shall have the meanings ascribed thereto in the Registration Rights
Agreement.

     In order to have Registrable Securities included in the Shelf Registration
Statement (or a supplement or amendment thereto), this Notice of Registration
Statement and Selling Securityholder Questionnaire ("Notice and
Questionnaire") must be completed, executed and delivered to the Company at the
address set forth herein for receipt ON OR BEFORE [insert date that is 30 days
from the Notice date] (the "Questionnaire Deadline"). Unless the Company
otherwise consents, beneficial owners of the Registrable Securities who do not
complete, execute and return this Notice and Questionnaire by such date (i) will
not be named as selling securityholders in the Shelf Registration Statement (or
a supplement or amendment thereto) and related Prospectus and (ii) may not sell
their Registrable Securities pursuant thereto. Beneficial owners of Registrable
Securities not having returned a Notice and Questionnaire by the Questionnaire
Deadline may, however, receive another Notice and Questionnaire from the Company
upon request. Following its receipt of a completed and signed Notice and
Questionnaire in return, the Company will promptly include the Registrable
Securities covered thereby in the Shelf Registration Statement.

     Certain legal consequences arise from being named as a selling
securityholder in the Shelf Registration Statement and related Prospectus.
Accordingly, holders and beneficial owners of Registrable Securities are advised
to consult their own securities law counsel regarding the consequences of being
named or not being named as a selling securityholder in the Shelf Registration
Statement and related Prospectus.

     The term "Registrable Securities" is defined in the Registration Rights
Agreement to mean all or any portion of the Notes issued under the Trust
Indenture and the Common Stock issuable upon conversion of such Notes, provided,
however, that a security ceases to be a Registrable Security when it is no
longer a Restricted Security.

     The term "Restricted Security" is defined in the Registration Rights
Agreement to mean any

                                       19
<PAGE>

Note or Common Stock issuable upon conversion thereof except any such Note or
Common Stock which (i) has been registered pursuant to an effective registration
statement under the Securities Act and sold in a manner contemplated by the
Shelf Registration Statement, (ii) has been transferred in compliance with Rule
144 under the Securities Act (or any successor provision thereto) or is
transferable pursuant to paragraph (k) of such Rule 144 (or any successor
provision thereto) or (iii) has otherwise been transferred and a new Note or
share of Common Stock not subject to transfer restrictions under the Securities
Act has been delivered by or on behalf of the Company in accordance with the
Indenture.

                                   ELECTION

     The undersigned holder (the "Selling Securityholder") of Registrable
Securities hereby elects to include in the Shelf Registration Statement the
Registrable Securities beneficially owned by it and listed below in item (3)
(unless otherwise specified under Item 3). The undersigned, by signing and
returning this Notice and Questionnaire, agrees to be bound with respect to such
Registrable Securities by the terms and conditions of this Notice and
Questionnaire and the Registration Rights Agreement, including, without
limitation, Section 5 of the Registration Rights Agreement, as if the
undersigned Selling Securityholder were an original party thereto.

     Upon any sale of Registrable Securities pursuant to the Shelf Registration
Statement, the Selling Securityholder will be required to deliver to the Company
and the Trustee the Notice of Transfer (completed and signed) set forth in
Exhibit 1 attached to this Notice and Questionnaire and hereby undertakes to do
so.

     The Selling Securityholder hereby provides the following information to the
Company and represents and warrants that such information is accurate and
complete:

                                 QUESTIONNAIRE

(1)  (a) Full Legal Name of Selling Securityholder:

     (b) Full Legal Name of Registered Holder (if not the same as in (a) above)
         of Registrable Securities Listed in (3) Below:

     (c) Full Legal Name of DTC Participant (if applicable and if not the same
         as (b) above) Through Which Registrable Securities Listed in (3) Below
         are Held:

(2)  Address for Notices to Selling Securityholder:


     Telephone:

                                       20
<PAGE>

     Fax:

     Contact:

(3)  Beneficial Ownership of Registrable Securities:

     Except as set forth below, the undersigned Selling Securityholder does not
     beneficially own any Notes or Common Stock previously issued upon
     conversion, repurchase or redemption of any Note.

     Principal amount of Notes beneficially owned:

     Number of shares of Common Stock beneficially owned and issued to date upon
     conversion, repurchase or redemption of Notes (if any):

     Principal amount of Notes which the undersigned wishes to be included in
     the Shelf Registration statement:

     Number of shares of Common Stock (if any) issued upon conversion,
     repurchase or redemption of Registrable Securities which are to be included
     in the Shelf Registration Statement:

(4)  Other shares of Common Stock or other Notes of the Company owned by the
     Selling Securityholder:

     Except as set forth below, and under item (3) above, the undersigned
     Selling Securityholder is not the beneficial or registered owner of any
     shares of Common Stock or any other securities of the Company.

State any exceptions here:


(5)  Relationships with the Company:

     Except as set forth below, neither the Selling Securityholder nor any of
     its affiliates, officers, directors or principal equity holders (5% or
     more) has held any position or office or has had any other material
     relationship with the Company (or its predecessors or affiliates) during
     the past three years.

State any exceptions here:


(6)  Plan of Distribution:

     Except as set forth below, the undersigned Selling Securityholder intends
     to distribute the Registrable Securities listed above in Item (3) only as
     follows (if at all): Such Registrable Securities may be sold from time to
     time directly by the undersigned Selling Securityholder

                                       21
<PAGE>

     or, alternatively, through underwriters, broker-dealers or agents. Such
     Registrable Securities may be sold in one or more transactions at fixed
     prices, at prevailing market prices at the time of sale, at varying prices
     determined at the time of sale, or at negotiated prices. Such sales may be
     effected in transactions (which may involve crosses or block transactions)
     (i) on any national securities exchanges or U.S. inter-dealer quotation
     system of a registered national securities association on which the
     Registrable Securities may be listed or quoted at the time of sale, (ii) in
     the over-the-counter market, (iii) in transactions otherwise than on such
     exchanges or services or in the over-the-counter market, or (iv) through
     the writing of options. In connection with sales of the Registrable
     Securities or otherwise, the Selling Securityholder may enter into hedging
     transactions with broker-dealers, which may in turn engage in short sales
     of the Registrable Securities in the course of hedging the positions they
     assume. The Selling Securityholder may also sell Registrable Securities
     short and deliver Registrable Securities to close out such short positions,
     or loan or pledge Registrable Securities to broker-dealers that in turn may
     sell such securities.

State any exceptions here:

     Note: In no event may such method(s) of distribution take the form of an
underwritten offering of the Registrable Securities without the prior agreement
of the Company.

     By signing below, the Selling Securityholder acknowledges that it
understands its obligation to comply, and agrees that it will comply, with the
prospectus delivery and other provisions of the Securities Act and Exchange Act
and the respective rules and regulations thereunder, particularly Regulation M.

     In the event that the Selling Securityholder transfers all or any portion
of the Registrable Securities listed in Item (3) above after the date on which
such information is provided to the Company, the Selling Securityholder agrees
to notify the transferee(s) at the time of the transfer of its rights and
obligations under this Notice and Questionnaire and the Registration Rights
Agreement.

     By signing below, the Selling Securityholder consents to the disclosure of
the information contained herein in its answers to Items (1) through (6) above
and the inclusion of such information in the Shelf Registration Statement and
related Prospectus. The Selling Securityholder understands that such information
will be relied upon by the Company in connection with the preparation of the
Shelf Registration Statement and related Prospectus.

     In accordance with the Selling Securityholder's obligation under the
Registration Rights Agreement to provide such information as may be required by
law for inclusion in the Shelf Registration Statement, the Selling
Securityholder agrees to promptly notify the Company of any inaccuracies or
changes in the information provided herein which may occur subsequent to the
date hereof at any time while the Shelf Registration Statement remains in
effect. All notices hereunder and pursuant to the Registration Rights Agreement
shall be made in writing by hand delivery, first-class mail, or air courier
guaranteeing overnight delivery as follows:

                                       22
<PAGE>

     To the Company:

         Rational Software Corporation
         18880 Homestead Road,
         Cupertino, CA 95014-0721
         Attention: Senior Director--Investor Relations

     Once this Notice and Questionnaire is executed by the Selling
Securityholder and received by the Company, the terms of this Notice and
Questionnaire, and the representations and warranties contained herein, shall be
binding on, shall inure to the benefit of and shall be enforceable by the
respective successors, heirs, personal representatives, and assigns of the
Company and the Selling Securityholder with respect to the Registrable
Securities beneficially owned by such Selling Securityholder and listed in Item
(3) above. This Agreement shall be governed in all respects by the laws of the
State of New York.

     IN WITNESS WHEREOF, the undersigned, by authority duly given, has caused
this Notice and Questionnaire to be executed and delivered either in person or
by its duly authorized agent.


Dated:


     Selling Securityholder
     (Print/type full legal name of beneficial owner
     of Registrable Securities)


     By:
     Name:
     Title:

     PLEASE RETURN THE COMPLETED AND EXECUTED NOTICE AND QUESTIONNAIRE FOR
RECEIPT ON OR BEFORE (DEADLINE FOR RESPONSE) TO THE COMPANY AT:

     Rational Software Corporation
     18880 Homestead Road,
     Cupertino, CA 95014-0721
     Attention: Senior Director--Investor Relations

                                       23
<PAGE>

                                                                       Exhibit B


             NOTICE TO TRANSFER PURSUANT TO REGISTRATION STATEMENT


Rational Software Corporation

18880 Homestead Road,

Cupertino, CA 95014-0721

Attention: Senior Director--Investor Relations


Re: Rational Software Corporation
     5% Convertible Subordinated Notes
    due February 1, 2007 (the "Notes")

Dear Sirs:

     Please be advised that          has transferred $       aggregate principal
amount of the above-referenced Notes or shares of the Company's Common Stock,
issued on conversion, repurchase or redemption of Notes, pursuant to the
Registration Statement on Form S-3 (File No. -   ) filed by the Company.

     We hereby certify that the prospectus delivery requirements, if any, of the
Securities Act of 1933, as amended, have been satisfied with respect to the
transfer described above and that the above-named beneficial owner of the Notes
or Common Stock is named as a selling securityholder in the Prospectus dated
______, 2000 or in amendments or supplements thereto, and that the aggregate
principal amount of the Notes or number of shares of Common Stock transferred
are [a portion of] the Notes or Common Stock listed in such Prospectus as
amended or supplemented opposite such owner's name.

                                        Very truly yours,


                                                          (Name)



                                        By:

                                                  (Authorized Signature)


 _ Dated:

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