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Exhibit 10.1

SECOND AMENDMENT TO NON-RECOURSE RECEIVABLES PURCHASE AGREEMENT

        This Second Amendment to Non-Recourse Receivables Purchase Agreement
(this "Amendment") is entered into as of September 30, 2004, by and between
SILICON VALLEY BANK, a California-chartered bank, with its principal place of
business at 3003 Tasman Drive, Santa Clara, California 95054 and with a loan
production office located at One Newton Executive Park, Suite 200, 2221
Washington Street, Newton, Massachusetts 02462, doing business under the name
"Silicon Valley East" ("Buyer") and ASPEN TECHNOLOGY,  INC., a Delaware
corporation with offices at Ten Canal Park, Cambridge, Massachusetts 02141
("Seller").

        1.    DESCRIPTION OF EXISTING AGREEMENT.    Reference is made to a
certain Non-Recourse Receivables Purchase Agreement by and between Buyer and
Seller dated as of December 31, 2003, as amended by a certain First Amendment to
Non-Recourse Receivables Purchase Agreement dated June 30, 3004 (as further
amended from time to time, the "Purchase Agreement"). Capitalized terms used but
not otherwise defined herein shall have the same meaning as in the Purchase
Agreement.

        2.    DESCRIPTION OF CHANGE IN TERMS.    

        Modification to Purchase Agreement.    The Purchase Agreement shall be
amended by deleting Section 2.1 thereof and inserting in lieu thereof the
following Section 2.1:

        "2.1    Sale and Purchase.    Subject to the terms and conditions of
this Agreement, with respect to each Purchase, effective on each applicable
Purchase Date, Seller agrees to sell to Buyer and Buyer agrees to buy from
Seller all right, title, and interest (but none of the obligations with respect
to) of the Seller to the payment of all sums owing or to be owing from the
Account Debtors under each Purchased Receivable to the extent of the Purchased
Receivable Amount for such Purchased Receivable.

        Each purchase and sale hereunder shall be in the sole discretion of
Buyer and Seller. In any event, Buyer will not (i) purchase any Receivables in
excess of an aggregate outstanding amount exceeding Thirty-Seven Million Dollars
($37,000,000.00), or (ii) purchase any Receivables under this Agreement after
January 1, 2005. The purchase of each Purchased Receivable may be evidenced by
an assignment or bill of sale in a form acceptable to Buyer."

        3.    FEES.    Seller shall pay to Buyer a modification fee of Five
Thousand Dollars ($5,000.00), which fee shall be due on the date hereof and
shall be deemed fully earned as of the date hereof. Seller shall also reimburse
Buyer for all legal fees and expenses incurred in connection with this
Amendment.

        4.    CONSISTENT CHANGES.    The Purchase Agreement is hereby amended
wherever necessary to reflect the changes described above.

        5.    RATIFICATION OF LOAN DOCUMENTS.    Seller hereby ratifies,
confirms, and reaffirms all terms and conditions of the Purchase Agreement.

        6.    CONTINUING VALIDITY.    Seller understands and agrees that in
modifying the Purchase Agreement, Buyer is relying upon Seller's
representations, warranties, and agreements, as set forth in the Purchase
Agreement. Except as expressly modified pursuant to this Amendment, the terms of
the Purchase Agreement remain unchanged and in full force and effect. Buyer's
agreement to modifications to the Purchase Agreement pursuant to this Amendment
in no way shall obligate Buyer to make any future modifications to the Purchase
Agreement.

        7.    NO DEFENSES OF SELLER.    Seller hereby acknowledges and agrees
that Seller has no offsets, defenses, claims, or counterclaims against Buyer
with respect to the Purchase Agreement or otherwise, and that if Seller now has,
or ever did have, any offsets, defenses, claims, or counterclaims against Buyer,
whether known or unknown, at law or in equity, all of them are hereby expressly
WAIVED and Seller hereby RELEASES Buyer from any liability thereunder.

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        8.    COUNTERSIGNATURE.    This Amendment shall become effective only
when it shall have been executed by Seller and Buyer.

        This Amendment is executed as a sealed instrument under the laws of the
Commonwealth of Massachusetts as of the date first written above.

SELLER:   BUYER:
ASPEN TECHNOLOGY, INC.
 
SILICON VALLEY BANK, doing business as SILICON VALLEY EAST
By:
 
/s/  CHARLES F. KANE      

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By:
 
/s/  JOHN PECK      

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Name:   Charles F. Kane   Name:   John Peck Title:   Senior VP and CFO   Title:
  Vice President

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SECOND AMENDMENT TO NON-RECOURSE RECEIVABLES PURCHASE AGREEMENT