LIMITED POWER OF ATTORNEY FOR SECTION 16 REPORTING OBLIGATIONS

Know all by these present, that the undersigned hereby makes,
constitutes and appoints each of Mark E. Fusco
and Charles F. Kane, signing singly and each acting
individually, as the undersigned's true and lawful
attorney-in-fact with full power and authority as hereinafter
described to:

(1)	execute for and on behalf of the undersigned, in the
undersigned's capacity as an officer and/or director of Aspen
Technology, Inc. (the "Company"), Forms 3, 4, and 5 (including
any amendments thereto) in accordance with Section 16(a) of the
Securities Exchange Act of 1934 and the rules thereunder (the
"Exchange Act");

(2)	do and perform any and all acts for and on behalf of the
undersigned which may be necessary or desirable to prepare,
complete and execute any such Form 3, 4, or 5, prepare, complete
and execute any amendment or amendments thereto, and timely
deliver and file such form with the United States Securities and
Exchange Commission and any stock exchange or similar authority;

(3)	seek or obtain, as the undersigned's representative and on
the undersigned's behalf, information regarding transactions in
the Company's securities from any third party, including brokers,
employee benefit plan administrators and trustees, and the
undersigned hereby authorizes any such person to release any such
information to such attorney-in-fact and approves and ratifies
any such release of information; and

(4)	take any other action of any type whatsoever in connection
with the foregoing which, in the opinion of such
attorney-in-fact, may be of benefit to, in the best interest of,
or legally required by, the undersigned, it being understood that
the documents executed by such attorney-in-fact on behalf of the
undersigned pursuant to this Power of Attorney shall be in such
form and shall contain such terms and conditions as such
attorney-in-fact may approve in such attorney-in-fact's
discretion.

The undersigned hereby grants to each such attorney-in-fact full
power and authority to do and perform any and every act and thing
whatsoever requisite, necessary, or proper to be done in the
exercise of any of the rights and powers herein granted, as fully
to all intents and purposes as the undersigned might or could do
if personally present, with full power of substitution or
revocation, hereby ratifying and confirming all that such
attorney-in-fact, or such attorney-in-fact's substitute or
substitutes, shall lawfully do or cause to be done by virtue of
this power of attorney and the rights and powers herein granted.
The undersigned acknowledges that the foregoing
attorneys-in-fact, in serving in such capacity at the request of
the undersigned, are not assuming nor relieving, nor is the
Company assuming nor relieving, any of the undersigned's
responsibilities to comply with Section 16 of the Exchange Act.
The undersigned acknowledges that neither the Company nor the
foregoing attorneys-in-fact assume (i) any liability for the
undersigned's responsibility to comply with the requirement of
the Exchange Act, (ii) any liability of the undersigned for any
failure to comply with such requirements, or (iii) any obligation
or liability of the undersigned for profit disgorgement under
Section 16(b) of the Exchange Act.

This Power of Attorney shall remain in full force and effect
until the undersigned is no longer required to file Forms 3, 4,
and 5 with respect to the undersigned's holdings of and
transactions in securities issued by the Company, unless earlier
revoked by the undersigned in a signed writing delivered to the
foregoing attorneys-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of
Attorney to be executed as of this 15th day of September, 2005.

/s/ Frederic G. Hammond
Frederic G. Hammond