Loan and Security Agreement

Exhibit 10.22(a)

February 14, 2003

Silicon Valley Bank
3003 Tasman Drive
Santa Clara, CA 95054
Attn: Commercial Finance Division, Division Credit Manager

Silicon Valley Bank
One Newton Executive Park, Suite 200
2221 Washington Street
Newton, MA 02462
Attn:  John V. Atanasoff

Re:          Aspen Technology — Schedule to Loan and Security Agreement

Reference is made in this letter agreement to the Loan and Security Agreement, dated as of January 30, 2003 (the “Loan Agreement”), by and among Aspen Technology, Inc., AspenTech, Inc. and Hyprotech Company (each, a “Borrower,” and collectively, the “Borrowers”) and Silicon Valley Bank (“SVB”).  Terms used and not otherwise defined in this letter agreement have the meanings given them in the Loan Agreement.

Pursuant to Section 9.10 (Amendment) of the Loan Agreement, the Borrowers and SVB hereby amend the Loan Agreement, effective as of January&