Exhibit
10.1


Stock Option Amendment — Award Identification No. P040380


Amendment
Number 1 (the “Amendment”) to the

Stock Option Agreement with Emmanouil Kotzabasakis

dated on or about August 18, 2003 under the

1995 Stock Option Plan, as amended (the “Plan”)


Dated as
of December 29, 2006


The Stock Option
Agreement (the “Option Agreement”) between Emmanouil Kotzabasakis and Aspen
Technology, Inc. (the “Company”) dated as of August 18, 2003 (the “Grant Date”)
with respect to non-qualified options to purchase 98,488 shares of common
stock of the Company (the “Shares”) is hereby amended as follows.


WHEREAS, the
Option Agreement was intended to have an Exercise Price Per Share equal to fair
market value (as defined in the Plan) at the time it was granted; and


WHEREAS, the
Company has since determined that there are reasonable grounds to conclude that
the Exercise Price Per Share specified in the Option Agreement was below fair
market value (as defined in the Plan) on the Grant Date; and


WHEREAS, the
Company and Emmanouil Kotzabasakis have determined that it is appropriate and
in their mutual best interests to increase the Exercise Price Per Share under
the Option Agreement to ensure that it is equal to the fair market value of the
Shares on the Grant Date.


NOW, THEREFORE, in
consideration of the mutual covenants contained herein, the receipt and
sufficiency of which are hereby acknowledged, the parties agree as follows:


1.               The Exercise Price
Per Share of $2.75 for the 67,711 Options which vest on or after January 1,
2005 is hereby changed to $2.85 (which represents the best currently available
estimate of the fair market value of the Shares on the Grant Date).


2.               The parties agree
that if the Company ultimately determines that the fair market value of the
Shares on the Grant Date was higher or lower than $2.85, then the Exercise
Price Per Share shall be further adjusted to be equal to such fair market
value.


3.               The Company agrees
that in the event that it makes any accommodation to other optionees who may
have the Exercise Price Per Share of their Options increased as a result of
such optionees having received an option which was issued with an exercise
price below fair market value on the applicable grant date, then the 









 



                        Company
will offer to make a similar accommodation for Emmanouil Kotzabasakis.


4.               The defined terms
in this Amendment shall have the same meanings as set forth in the Option
Agreement and the Plan.


5.               Except as set forth
in this Amendment, all other terms and conditions of the Option Agreement shall
remain in full force and effect.


IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be
executed as of the date first written above.


	
  

  	
  Aspen Technology, Inc.

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
  By: 

  	
  /s/ B.T. Miller

  	
   

  	
  By: 

  	
  /s/ E. Kotzabasakis

  
	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  Name: Bradley
  Miller

  	
   

  	
   

  	
  Name: E.M. Kotzabasakis

  
	
   

  	
   

  	
  Title: CFO

  	
   

  	
   

  	
  Title: SVP Sales