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    AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON SEPTEMBER 9, 1996

                                                           FILE NO. 33-________

- --------------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

                         ------------------------------
                                    FORM S-8

                          REGISTRATION STATEMENT UNDER
                           THE SECURITIES ACT OF 1933

                         ------------------------------

                             ASPEN TECHNOLOGY, INC.
             (Exact Name of Registrant as Specified in its Charter)


                MASSACHUSETTS                                04-2739697
       (State Or Other Jurisdiction Of                    (I.R.S. Employer
       Incorporation Or Organization)                    Identification No.)

                       TEN CANAL PARK, CAMBRIDGE, MA 02141
               (Address of Principal Executive Offices) (Zip Code)

                         ------------------------------

           ASPEN TECHNOLOGY, INC. 1995 EMPLOYEES' STOCK PURCHASE PLAN
             ASPEN TECHNOLOGY, INC. 1995 DIRECTORS STOCK OPTION PLAN
                  ASPEN TECHNOLOGY, INC. 1995 STOCK OPTION PLAN
                           (Full Titles of the Plans)

                         ------------------------------

                                LAWRENCE B. EVANS
                     CHAIRMAN OF THE BOARD OF DIRECTORS AND
                             CHIEF EXECUTIVE OFFICER
                             ASPEN TECHNOLOGY, INC.
                                 Ten Canal Park
                               Cambridge, MA 02141
                     (Name and address of Agent for Service)



                                 (617) 577-0100
           Telephone Number, Including Area Code, of Agent for Service

                         ------------------------------


                                    Copy to:

                             RICHARD M. HARTER, ESQ.
                            BINGHAM, DANA & GOULD LLP
                               150 Federal Street
                              Boston, MA 02110-1726
                                 (617) 951-8000



                                                  CALCULATION OF REGISTRATION FEE
===================================================================================================================

                                                              PROPOSED           PROPOSED
                                           AMOUNT             MAXIMUM             MAXIMUM           AMOUNT OF
       TITLE OF EACH CLASS OF               TO BE          OFFERING PRICE        AGGREGATE         REGISTRATION
    SECURITIES TO BE REGISTERED          REGISTERED          PER SHARE*       OFFERING PRICE*          FEE
- -------------------------------------------------------------------------------------------------------------------
                                                                                                   
Common Stock, $.10 par value .....        1,654,685           $65.87           $108,994,101         $37,584.17
===================================================================================================================

<FN>

*    The proposed maximum offering price has been calculated in accordance with
     the provisions of Rule 457(h) based on the average of the high and low
     prices reported in the consolidated reporting system on September 5, 1996.
     It is not known how many shares, if any, will be purchased upon exercise of
     options granted under the Plans or at what price such shares will be
     purchased.



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                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.

         The following documents filed by Aspen Technology, Inc. (the
"Registrant") with the Securities and Exchange Commission (the "SEC") are hereby
incorporated by reference in this Registration Statement: (a) the Registrant's
Annual Report on Form 10-K for the fiscal year ended June 30, 1995; (b) all
reports previously filed by the Registrant pursuant to Section 13(a) or 15(d) of
the Securities Exchange Act of 1934, as amended (the "Exchange Act"), since the
end of the Registrant's 1995 fiscal year; and (c) the description of the Common
Stock contained in the Registrant's registration statement filed with the SEC
under Section 12(g) of the Exchange Act, including any amendment or report
filed for the purpose of updating such description.

         In addition, all documents subsequently filed by the Registrant
pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act prior to the
filing of a post-effective amendment which indicate that all securities offered
hereby have been sold or which deregister all of such securities then remaining
unsold, shall be deemed to be incorporated by reference into this Registration
Statement and to be a part hereof from the date of filing of such documents.

ITEM 4.  DESCRIPTION OF SECURITIES

         Not applicable.

ITEM 5.  INTERESTS OF NAMED EXPERTS OR COUNSEL

         Richard M. Harter, Esq., a partner at the Registrant's legal counsel,
Bingham, Dana & Gould LLP, is the Clerk of the Registrant and owns a total of
10,000 shares of Common Stock of the Registrant.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS

         Section 67 of Chapter 156B of the Massachusetts General Laws provides a
statutory framework covering indemnification of directors and officers against
liabilities and expenses arising out of legal proceedings brought against them
by reason of their status or service as directors or officers. In addition,
Article VII of the Registrant's By-Laws provides for indemnification of
Directors, officers and employees of the Registrant. Section 67 and the
Registrant's By-Laws generally provide that a Director, officer or employee of
the Registrant shall be indemnified by the Registrant for all expenses and
liabilities of legal proceedings brought against him/her by reason of his/her
status or service as a Director, officer or employee unless the Director,
officer or employee is adjudged not to have acted in good faith in the
reasonable belief that his/her action was in the best interest of the Registrant
or, to the extent that such matter relates to service with respect to an
employee benefit plan, in the best interests of the participants or
beneficiaries of such plan. The Registrant's Restated Articles of Organization
also incorporate certain provisions permitted under the Massachusetts General
Laws relating to the liability of Directors. The provisions eliminate a
Director's liability for monetary damages for a breach of fiduciary duty,
including gross negligence, except in circumstances involving certain wrongful
acts, such as the breach of a Director's duty of loyalty or acts or omissions
not in good faith or which involve intentional misconduct or a knowing violation
of law or authorization of distributions in violation of the Restated Articles
of Organization or of loans to officers or Directors of the Registrant or any
transaction from which the Director derived an improper personal benefit. These
provisions do not eliminate a Director's duty of care. Moreover, the provisions
do not apply to claims against a Director for violations of certain laws,
including federal securities laws.


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ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED

         Not applicable.

ITEM 8.  EXHIBITS

         The following exhibits are filed as part of this Registration
Statement:

           4.1      Restated Articles of Organization of the Registrant,
                    incorporated by reference to Exhibit 3.1 to the Registration
                    Statement on Form S-1 of the Registrant (Registration No.
                    32-88734) filed with the SEC on January 29, 1995.

           4.2      By-Laws of Registrant, incorporated by reference to Exhibit
                    3.3 to the Registration Statement on Form S-1 of the
                    Registrant (Registration No. 33-83916) filed with the SEC on
                    September 13, 1994.

           4.3      The Registrant's 1995 Employees' Stock Purchase Plan

           4.4      The Registrant's 1995 Directors Stock Option Plan.

           4.5      The Registrant's 1995 Stock Option Plan

             5      Opinion and Consent of Bingham, Dana & Gould LLP, counsel to
                    the Registrant, with respect to the legality of the shares
                    being registered.

          23.1      Consent of Arthur Andersen LLP.

          23.2      Consent of Bingham, Dana & Gould LLP (included in Exhibit
                    5).

            24      Power of Attorney (included in signature page to
                    Registration Statement).

ITEM 9.  UNDERTAKINGS

         The undersigned Registrant hereby undertakes:

               (1)    To file, during any period in which offers or sales are
         being made, a post-effective amendment to this Registration Statement,
         to include any material information with respect to the plan of
         distribution not previously disclosed in this Registration Statement or
         any material change to such information in this Registration Statement;

               (2)    That, for the purpose of determining any liability under
         the Securities Act, each such post-effective amendment shall be deemed
         to be a new registration statement relating to the securities offered
         therein, and the offering of such securities at that time shall be
         deemed to be the initial bona fide offering thereof;

               (3)    To remove from registration by means of a post-effective
          amendment any of the securities being registered which remain unsold
          at the termination of the offering;

               (4)    That, for purposes of determining any liability under the
         Securities Act of 1933 (the "Securities Act"), each filing of the
         Registrant's annual report pursuant to Section 13(a) or 15(d) of the
         Exchange Act (and, where applicable, each filing of an employee benefit
         plan's annual report pursuant to Section 15(d) of the Exchange Act)
         that is incorporated by reference in the Registration Statement shall
         be deemed to be a new registration statement relating to the securities
         offered 

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          therein, and the offering of such securities at that time shall be
          deemed to be the initial bona fide offering thereof; and

               (5)    Insofar as indemnification for liabilities arising under
         the Securities Act may be permitted to directors, officers and
         controlling persons of the Registrant pursuant to the foregoing
         provisions, or otherwise, the Registrant has been advised that in the
         opinion of the SEC such indemnification is against public policy as
         expressed in the Securities Act and is, therefore, unenforceable. In
         the event that a claim for indemnification against such liabilities
         (other than the payment by the Registrant of expenses incurred or paid
         by a director, officer or controlling person of the Registrant in the
         successful defense of any action, suit or proceeding) is asserted by
         such director, officer or controlling person in connection with the
         securities being registered, the Registrant will, unless in the opinion
         of its counsel the matter has been settled by controlling precedent,
         submit to a court of appropriate jurisdiction the question whether such
         indemnification by it is against public policy as expressed in the
         Securities Act and will be governed by the final adjudication of such
         issue.



                  [Remainder of page intentionally left blank]



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                                   SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, as amended,
the Registrant certifies that it has reasonable grounds to believe that it meets
all of the requirements for filing Form S-8 and has duly caused this
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Cambridge, Commonwealth of Massachusetts, on
this 5th day of September, 1995.

                                        ASPEN TECHNOLOGY, INC.


                                        By: /s/ Lawrence B. Evans
                                           ------------------------------------
                                                Lawrence B. Evans, Chairman


                                POWER OF ATTORNEY

         Each person whose signature appears below hereby appoints Lawrence B.
Evans, Mary A. Palermo, Joel B. Rosen and Sharon A. Turley and each of them
severally, acting alone and without the other, his/her true and lawful
attorney-in-fact with the authority to execute in the name of each such person,
and to file with the Securities and Exchange Commission, together with any
exhibits thereto and other documents therewith, any and all amendments
(including without limitation post-effective amendments) to this Registration
Statement on Form S-8 necessary or advisable to enable the Registrant to comply
with the Securities Act of 1933, as amended, and any rules, regulations and
requirements of the Securities and Exchange Commission in respect thereof, which
amendments may make such other changes in this Registration Statement as the
aforesaid attorney-in-fact executing the same deems appropriate.

         Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below by the following persons in the
capacity indicated on the 5th day of September, 1996.

         SIGNATURE                                TITLE
         ---------                                -----

/s/ Lawrence B. Evans            Chairman of the Board of Directors and Chief
- -----------------------------    Executive Officer (Principal Executive Officer)
    LAWRENCE B. EVANS                                

/s/ Mary A. Palermo              Executive Vice President (Principal Accounting
- -----------------------------    Officer and Principal Financial Officer)
    MARY A. PALERMO                                  

/s/ Joseph F. Boston             Director
- -----------------------------
    JOSEPH F. BOSTON

                                 Director
- -----------------------------
    GRESHAM T. BREBACH, JR.

/s/ Douglas R. Brown             Director
- -----------------------------
    DOUGLAS R. BROWN

/s/ Joan C. McArdle              Director
- -----------------------------
    JOAN C. MCARDLE

                                 Director
- -----------------------------
    ALISON ROSS

                                 Director
- -----------------------------
    WILLIAM C. ROUSSEAU



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                                     INDEX TO EXHIBITS



EXHIBIT NUMBER                      DESCRIPTION                                     SEQUENTIAL PAGE NO.
- --------------                      -----------                                     -------------------

                                                                                      
    4.1        Restated Articles of Organization of the Registrant, incorporated
               by reference to Exhibit 3.1 to the Registration Statement on Form
               S-1 of the Registrant (Registration No. 32-88734) filed with the
               SEC on January 29, 1995.

    4.2        By-Laws of Registrant, incorporated by reference to Exhibit 3.3
               to the Registration Statement on Form S-1 of the Registrant
               (Registration No. 33-83916) filed with the SEC on September 13,
               1994.

    4.3        The Registrant's 1995 Employees' Stock Purchase Plan                          

    4.4        The Registrant's 1995 Directors Stock Option Plan.                           

    4.5        The Registrant's 1995 Stock Option Plan                                      

     5         Opinion and Consent of Bingham, Dana & Gould LLP with respect to
               the legality of the shares being registered.                                 

   23.1        Consent of Arthur Andersen LLP.                                              

   23.2        Consent of Bingham, Dana & Gould LLP (included in Exhibit 5).

    24         Power of Attorney (included in signature page to Registration
               Statement).