Aspen Technology 10-Q 2010 Q3 Quarterly report

EXHIBIT 32.1

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report on Form 10-Q of Aspen Technology, Inc. (the “Company”) for the quarter ended March 31, 2010, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), the undersigned President and Chief Executive Officer and Senior Vice President and Chief Financial Officer, certify, to the best knowledge and belief of the signatory, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

1.The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2.The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Date: May 6, 2010	/s/ MARK E. FUSCO
	Mark E. Fusco
	President and Chief Executive Officer
Date: May 6, 2010	/s/ MARK P. SULLIVAN
	Mark P. Sullivan
	Senior Vice President and Chief Financial Officer

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