Filed by Rational Software Corporation
Pursuant to Rule 425 under the Securities Act of 1933
and deemed filed pursuant to Rule 14a-12
of the Securities Exchange Act of 1934
Subject Company: Rational Software Corporation
(Commission File No. 000-12167)

The following was first
distributed on November 28, 2000

Additional Information and Where to Find It

In connection with the proposed transaction with Catapulse, Rational will file a registration statement on Form S-4, including a proxy statement-prospectus, with the Securities and Exchange Commission. Investors and security holders are advised to read the registration statement, including the proxy statement-prospectus when they become available because they will contain important information about the proposed merger. Investors and security holders may obtain a free copy of the registration statement and the proxy statement-prospectus (when available) and other documents filed by Rational with the Securities and Exchange Commission at the Securities and Exchange Commission's web site at http://www/sec.gov. Free copies of the registration statement (when available) and other documents filed by Rational with the Securities and Exchange Commission may also be obtained from Rational by directing a request to Rational, Attention: Tim Brennan, 408-863-9900.

Rational and its directors and executive officers may be deemed to be participants in the solicitation of proxies from Rational stockholders in favor of the proposed transaction. These directors and executive officers include Paul Levy, Michael Devlin, Les Denend, Al Schleicher, John Montague, Tom Bogan and Tim Brennan. Collectively, as of March 31, 2000, the directors and executive officers of Rational may be deemed to beneficially own approximately 6.4% of the outstanding shares of Rational common stock. Investors and security holders may obtain additional information regarding the interests of the participants by reading the registration statement and proxy statement-prospectus when they become available.