SCHEDULE 14A
                                (Rule 14a-101)

                    INFORMATION REQUIRED IN PROXY STATEMENT

                            SCHEDULE 14A INFORMATION

          Proxy Statement Pursuant to Section 14(a) of the Securities
                              Exchange Act of 1934

Filed by the Registrant [X]

Filed by a Party other than the Registrant [_]


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                                             Commission Only (as Permitted by
                                             Rule 14a-6(e)(2))

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[X] Soliciting Material Under Rule 14a-12


                        PERITUS SOFTWARE SERVICES, INC.
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                (Name of Registrant as Specified in Its Charter)

                                Not Applicable.
- --------------------------------------------------------------------------------
    (Name of Person(s) Filing Proxy Statement, if Other Than the Registrant)

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    1.  Title of each class of securities to which transaction applies:

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    3.  Per unit price or other underlying value of transaction computed
        pursuant to Exchange Act Rule 0-11 (set forth the amount on which the
        filing fee is calculated and state how it was determined):

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[_] Fee paid previously with preliminary materials.

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    4.  Date Filed:

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                                        Filed by Peritus Software Services, Inc.
               Pursuant to Rule 14a-12 under the Securities Exchange Act of 1934

                               Subject Company:  Peritus Software Services, Inc.
                                                 Commission File No.:  000-22647


                                                           For Immediate Release

  Peritus Software Services Announces It Has Executed an Agreement and Plan of
                       Merger with Rocket Software, Inc.


WESTBOROUGH, MA. - APRIL 18, 2001 - Peritus Software Services, Inc. (OTC:
PTUS.OB), a provider of solutions for software maintenance technology and
services, today announced it has executed an Agreement and Plan of Merger with
Rocket Software, Inc. ("Rocket") and Rocket Acquisition Company, Inc.  The
Company had previously announced on March 28, 2001 that it had received a non-
binding offer from Rocket.  Rocket currently owns 10,000,000 shares of the
Company's common stock representing 36.6% of the total outstanding shares of
27,319,903.

Under the terms of the Agreement, Rocket Acquisition Company, a subsidiary of
Rocket, would be merged into Peritus.  All Peritus shareholders other than
Rocket would be paid $0.19 per share in cash in exchange for their Peritus
shares.

The Agreement provides that the transaction must be completed before June 30,
2001 and that the Company must have at least $4,810,000 in cash at closing after
subtraction of the lesser of $840,000 or the actual transaction costs.
Completion of the transaction is subject to approval by the holders of a
majority of Peritus' outstanding Common Stock, obtaining the requisite third
party and governmental consents and other customary closing conditions.

This press release may contain certain forward-looking statements, which involve
risks and uncertainties.  The Company's actual results could differ materially
from those anticipated in those forward looking statements as a result of
various factors, including the risks described in the Company's Annual Report on
Form 10-K for the year ended December 31, 2000 and other public filings made by
Peritus with the Securities and Exchange Commission, which factors are
incorporated herein by reference.  From time to time, the Company may also
provide oral and or written forward-looking statements in other materials it
releases to the public.  The Company does not assume any obligation to update
any of the forward-looking statements it makes.

IMPORTANT INFORMATION AND WHERE TO FIND IT

Peritus Software Services, Inc. plans to file a proxy statement with the
Securities and Exchange Commission relating to its proposed business combination
with Rocket Software, Inc.  Investors and stockholders are urged to read the
proxy statement when it becomes available, because it will contain important
information about Peritus, the proposed business combination with Rocket
Software and related matters.  When the proxy statement is completed, Peritus
plans to send it to its stockholders to seek their approval of the proposed
business combination.  A free copy of the proxy statement (when it is filed) and
other documents filed by Peritus with the SEC are available for free at the
SEC's web site at http://www.sec.gov.  Peritus' stockholders may also

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obtain the proxy statement and other documents without charge by directing a
request to Peritus Software Services, Inc., Attention: Ronald C. Garabedian, 112
Turnpike Road, Suite 111, Westborough, Massachusetts 01581, Telephone: (508)
870-0963. Peritus, Rocket Software, their respective directors, executive
officers and employees and certain other persons may be deemed to be
participants in the solicitation of proxies from Peritus' stockholders to
approve the proposed business combination between Peritus and Rocket Software.
These individuals may have interests in the proposed business combination, some
of which may differ from or may be in addition to those of Peritus' stockholders
generally. A description of the participants in the solicitation, and their
relevant affiliations and interests, will be contained in Peritus' proxy
statement with respect to the proposed business combination with Rocket
Software, when it is filed with the SEC.

ABOUT PERITUS

Founded in 1991, Peritus Software Services, Inc. offers products and services
that enable organizations to improve the productivity, effectiveness and quality
of the software evolution process.  The Peritus Software Asset Maintenance (SAM)
offerings enable organizations to transform the maintenance process into an
efficient, cost-effective discipline that boosts productivity and performance.
Peritus is headquartered in Westborough, MA.

Contact:  Ronald C. Garabedian
          Vice President and Treasurer
          Peritus Software Services, Inc.
          Phone:  508-870-0963
          Fax:  508-870-0764

E-mail:   rgarabedian@peritus.com
          -----------------------

Peritus is a registered trademark of Peritus Software Services, Inc.

ABOUT ROCKET

Founded in 1990, Rocket Software, Inc. is a software engineering organization
providing enterprise class software products and services.  Rocket is
headquartered in Natick, MA.

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