Aspen Technology Announces Delisting From NASDAQ Effective February 19, 2008

Burlington, Mass. – February 14, 2008 – Aspen Technology, Inc. (AZPN) announced today
that the Nasdaq Listing Qualifications Panel (the “Panel”) has determined to delist the
Company’s securities and will suspend trading of the Company’s securities on the Nasdaq stock
market effective at the opening of trading on February 19, 2008.

The Company may request that the Nasdaq Listing and Hearing Review Council review the
decision of the Panel. If the Listing Council determines to review this decision, it may affirm,
modify, reverse, dismiss, or remand the decision to the Panel. The Company is considering
whether to make such a request. However, such a request would not delay the Panel’s
determination to delist the Company’s securities.

The Company anticipates that its common stock will be quoted on the Pink Sheet Electronic
Quotation Service automatically and immediately after Nasdaq suspends trading. The Company
expects that the trading symbol of its common stock will remain the same (AZPN or AZPN.PK).
Information about the Pink Sheets can be found at its Internet website www.pinksheets.com.

Mark Fusco, Chief Executive Officer of the Company, said: “We are disappointed that the time it
has taken for the review we initiated in connection with the restatement of our financial
statements has resulted in the delisting of our common stock. We believe AspenTech remains a
financially strong company as evidenced by our cash and cash equivalents of $131 million as of
December 31, 2007, and we are committed to regaining Compliance with our filing requirements
and applying to list our common stock on a national exchange as soon as possible thereafter.”
The Company has previously issued several press releases and filed several reports with the SEC
including reports on Form 8-K, and investors are encouraged to read these in their entirety for
discussion of the delay in the Company’s filings.