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  Exhibit 10.43    
    


 
    Aspen Technology, Inc.    
    
    Terms and Conditions of Stock Option Agreement
  Granted Under 2010 Equity Incentive Plan    
    


        1.    Grant of Option.    


        These
terms and conditions together with the notice of grant of stock option (the "Notice") set forth on the cover page to which they are attached constitute an Agreement evidencing the
grant by Aspen Technology, Inc., a Delaware corporation (the "Company"), on the grant date set forth in the Notice (the "Grant Date") to the employee named in the Notice (the "Participant"), of
an option to purchase, in whole or in part, on the terms provided herein and in the Company's 2010 Equity Incentive Plan (the "Plan"), the number of shares (the "Shares") of common stock, $0.10 par
value per share, of the Company ("Common Stock") set forth on the Notice, at a strike price set forth per Share set forth in the Notice. Unless earlier terminated, this Agreement shall expire at
5:00 p.m., Eastern Time, on the Expiration Date set forth in the Notice (the "Final Exercise Date"). 


        To
the extent permitted by the Code (as defined below) and designated in the Notice, it is intended that the option evidenced by this Agreement shall be an incentive stock option as
defined in Section 422
of the Internal Revenue Code of 1986, as amended, and any regulations promulgated thereunder (the "Code") or a nonqualified stock option, to the extent designated in this Notice. 



        2.    Vesting Schedule.    


        The
options granted hereunder will vest according to the schedule set forth on the Notice. The right of exercise shall be cumulative so that to the extent the option is not exercised in
any period to the maximum extent permissible it shall continue to be exercisable, in whole or in part, with respect to all Shares for which it is vested until the earlier of the Final Exercise Date or
the termination of this Agreement under Section 3 hereof or the Plan. 


        3.    Exercise of Option.    



        (a)   Form of Exercise.    Each election to exercise this Agreement shall be in the manner permitted by the Company's
third party stock incentive plan administrator. If no such third party administrator is administering the Plan at such time, such election shall be in writing, signed by the Participant and received
by the Company at its principal office, accompanied by this Agreement and payment in full in the manner provided in the Plan, or as otherwise provided in the Plan. The Participant may purchase less
than the number of shares covered hereby, provided that no partial exercise of this Agreement may be for any fractional share. 



        (b)   Continuous Relationship with the Company Required.    Except as otherwise provided in this Section 3,
this Agreement may not be exercised unless the Participant, at the time he or she exercises this Agreement, is, and has been at all times since the Grant Date, an employee or officer of, or consultant
or advisor to, the Company or any parent or subsidiary of the Company as defined in Section 424(e) or (f) of the Code (an "Eligible Participant"). 


        (c)   Termination of Relationship with the Company.    If the Participant ceases to be an Eligible Participant for
any reason, then, except as provided in paragraphs (d) and (e) below, the right to exercise this Agreement shall terminate three months after such cessation (but in no event after the
Final Exercise Date), provided that this Agreement shall be exercisable only to the extent that the Participant was entitled to exercise this Agreement
on the date of such cessation. Notwithstanding the foregoing, if the Participant, prior to the Final Exercise Date, violates the non-competition or confidentiality provisions of any
employment contract, confidentiality and nondisclosure agreement or other agreement between the Participant and the Company, the right to exercise this Agreement shall terminate immediately upon such
violation. 


        (d)   Exercise Period Upon Death or Disability.    Unless otherwise agreed by the Company and the Participant, if the
Participant dies or becomes disabled (within the meaning of Section 22(e)(3) of the 










Code)
prior to the Final Exercise Date while he or she is an Eligible Participant and the Company has not terminated such relationship for "cause" as specified in paragraph (e) below, this
Agreement shall be exercisable, within the period of eighteen months following the date of death, or one year following the date of disability, of the Participant, by the Participant (or in the case
of death by an authorized transferee), provided that this Agreement shall be exercisable only to the extent that this Agreement was exercisable by the
Participant on the date of his or her death or disability, and further provided that this Agreement shall not be exercisable after the Final Exercise
Date. 


        (e)   Termination for Cause.    If, prior to the Final Exercise Date, the Participant's employment is terminated by
the Company for Cause (as defined below), the right to exercise this Agreement shall terminate immediately upon the effective date of such termination of employment, unless otherwise agreed by the
Company and the Participant. If the Participant is party to an employment or severance agreement with the Company that contains a definition of "cause" for termination of employment, "Cause" shall
have the meaning ascribed to such term in such agreement. Otherwise, "Cause" shall mean (i) any willful failure by the Participant, which failure is not cured within 30 days of written
notice to the Participant from the Company, to perform his or her material responsibilities to the Company, or (ii) willful misconduct by the Participant that affects the business reputation of
the Company, in either case as determined by the Company, which determination shall be conclusive. 


        4.    Tax Matters.    



        (a)   Withholding.    No Shares will be issued pursuant to the exercise of this Agreement unless and until the
Participant pays to the Company, or makes provision satisfactory to the Company for payment of, any federal, state or local withholding taxes required to be withheld in respect of this Agreement. 


        (b)   Disqualifying Disposition.    To the extent the option is an incentive stock option, if the Participant
disposes of Shares acquired upon exercise of this Agreement within two years from the Grant Date or one year after such Shares were acquired pursuant to exercise of this Agreement, the Participant
shall notify the Company in writing of such disposition. 


        5.    Nontransferability of Option.    


        This
Agreement may not be sold, assigned, transferred, pledged or otherwise encumbered by the Participant, either voluntarily or by operation of law, except by will or the laws of
descent and
distribution, and, during the lifetime of the Participant, this Agreement shall be exercisable only by the Participant. 


        6.    Provisions of the Plan.    


        This
Agreement is subject to the provisions of the Plan. 











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Exhibit 10.43


Aspen Technology, Inc. Terms and Conditions of Stock Option Agreement Granted Under 2010 Equity Incentive Plan