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                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

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                                   FORM 8-A/A

                                 AMENDMENT NO. 1

                FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES
                    PURSUANT TO SECTION 12(b) OR 12(g) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

                             ASPEN TECHNOLOGY, INC.
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             (Exact name of registrant as specified in its charter)

                DELAWARE                                 04-2739697
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(State of incorporation or organization)    (I.R.S. employer identification no.)

TEN CANAL PARK, CAMBRIDGE, MASSACHUSETTS                             02141
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(Address of principal executive offices)                          (Zip code)

If this form relates to the               If this form relates to the
registration of a class of securities     registration of a class of securities 
pursuant to Section 12(b) of the          pursuant to Section 12(g) of the
Exchange Act and is effective pursuant    Exchange Act and is effective pursuant
to General Instruction A.(c), check       to General Instruction A.(d), check
the following box. [ ]                    the following box. [X]


Securities Act registration statement number 
to which this form relates: ____________________________________ (If applicable)


Securities to be registered pursuant to Section 12(b) of the Act:

Title of each class                              Name of each exchange on
to be so registered                        which each class is to be registered
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       NONE.

Securities to be registered pursuant to Section 12(g) of the Act:

                           RIGHTS TO PURCHASE SERIES A
                    PARTICIPATING CUMULATIVE PREFERRED STOCK
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                                (Title of Class)

         The undersigned registrant hereby amends the following items, exhibits
and portions of its registration statement on Form 8-A (dated as of October 9,
1997) as set forth in the pages attached hereto:


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ITEM 1.   DESCRIPTION OF REGISTRANT'S SECURITIES TO BE REGISTERED.

     On March 12, 1998, Aspen Technology, Inc., a Massachusetts corporation
("Aspen Massachusetts"), changed its state of incorporation by merging with and
into Aspen Technology, Inc., a Delaware corporation and wholly owned subsidiary
of Aspen Massachusetts (the "Company"). In connection with the reincorporation,
the Board of Directors of the Company determined to adopt a stockholder rights
plan equivalent to the stockholder rights plan adopted on October 9, 1997 by the
Board of Directors of Aspen Massachusetts. On March 12, 1998, the Board of
Directors of the Company declared a dividend of one Right for each outstanding
share of Common Stock, $.10 par value per share, of the Company (the "Common
Shares"). The Rights were issued to the holders of record of Common Shares
outstanding on March 12, 1998, and have been and will be issued with respect to
Common Shares issued thereafter until the Distribution Date (as defined below)
and, in certain circumstances, with respect to Common Shares issued after the
Distribution Date. Each Right, when it becomes exercisable as described below,
will entitle the registered holder to purchase from the Company one
one-hundredth (1/100th) of a share of Series A Participating Cumulative
Preferred Stock, $.10 par value per share, of the Company (the "Preferred
Shares") at a price of $175.00 (the "Purchase Price"). The description and terms
of the Rights are set forth in the Rights Agreement dated as of March 12, 1998
(the "Rights Agreement") between the Company and American Stock Transfer and
Trust Company, as Rights Agent (the "Rights Agent").

     Until the earlier of (i) such time as the Company learns that a person or
group (including any affiliate or associate of such person or group) acquired,
or obtained the right to acquire, beneficial ownership of 15% or more of the
outstanding Common Shares (such person or group being called an "Acquiring
Person") or (ii) such date, if any, as may be designated by the Board of
Directors of the Company following the commencement of, or first public
disclosure of an intent to commence, a tender or exchange offer for outstanding
Common Shares which could result in the offeror becoming the beneficial owner of
15% or more of the outstanding Common Shares (the earlier of such dates being
called the "Distribution Date"), the Rights will be evidenced by the
certificates for Common Shares registered in the names of the holders thereof
(which certificates for Common Shares shall also be deemed to be Right
Certificates, as defined below) and not by separate Right Certificates.
Therefore, until the Distribution Date, the Rights will be transferred with and
only with the Common Shares.

     As soon as practicable following the Distribution Date, separate
certificates evidencing the Rights ("Right Certificates") will be mailed to
holders of record of the Common Shares as of the close of business on the
Distribution Date (and to each initial record holder of certain Common Shares
originally issued after the Distribution Date), and such separate Right
Certificates alone will thereafter evidence the Rights.

     The Rights are not exercisable until the Distribution Date and will expire
on March 12, 2008 (the "Expiration Date"), unless earlier redeemed by the
Company as described below.

     To preserve the actual or potential economic value of the Rights, the
number of Preferred Shares or other securities issuable upon exercise of a
Right, the Purchase Price and Redemption Price and the number of Rights
associated with each outstanding Common Share are all subject to adjustment by
the Board of Directors as provided in the Rights Agreement in the event of any
change in the Common Shares or Preferred Shares, whether by reason of stock
dividends, stock splits, recapitalizations, mergers, consolidations,
combinations or exchanges of securities, split-ups, split-offs, spin-offs,
liquidations, other similar changes in capitalization, any distribution or
issuance of cash, assets, evidences of indebtedness or subscription rights,
options or warrants to holders of Common Shares or Preferred Shares, as the case
may be (other than distribution of the Rights or regular quarterly cash
dividends) or otherwise.





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     The Preferred Shares are authorized to be issued in fractions which are an
integral multiple of one one-hundredth (1/100th) of a Preferred Share. The
Company may, but is not required to, issue fractions of shares upon the exercise
of Rights, and, in lieu of fractional shares, the Company may issue certificates
or utilize a depository arrangement as provided by the terms of the Preferred
Shares and, in the case of fractions other than one one-hundredth (1/100th) of a
Preferred Share or integral multiples thereof, may make a cash payment based on
the market price of such shares.

     Upon a person or a group becoming an Acquiring Person, the Rights will
entitle each holder of a Right to purchase, for the Purchase Price, that number
of one one-hundredths (1/100ths) of a Preferred Share equivalent to the number
of Common Shares which at the time of the transaction would have a market value
of twice the Purchase Price.

     In the event the Company is acquired in a merger or other business
combination or 50% or more of its assets or assets representing 50% or more of
its earning power are sold, leased, exchanged or otherwise transferred (in one
or more transactions) to a publicly traded corporation, each Right will entitle
its holder to purchase, for the Purchase Price, that number of Common Shares of
such corporation which at the time of the transaction would have a market value
of twice the Purchase Price. In the event the Company is acquired in a merger or
other business combination or 50% or more of its assets or assets representing
50% or more of the earning power of the Company are sold, leased, exchanged or
otherwise transferred (in one or more transactions) to an entity that is not a
publicly traded corporation, each Right will entitle its holder to purchase, for
the Purchase Price, at such holder's option, (i) that number of shares of such
entity (or, at such holder's option, of the surviving corporation in such
acquisition, which could be the Company) which at the time of the transaction
would have a book value of twice the Purchase Price or (ii) if such entity has
an affiliate which has publicly traded Common Shares, that number of Common
Shares of such affiliate which at the time of the transaction would have a
market value of twice the Purchase Price.

     Any Rights that are at any time beneficially owned by an Acquiring Person
(or any affiliate or associate of an Acquiring Person) shall be null and void
and nontransferable, and any holder of any such Right (including any purported
transferee or subsequent holder) shall not have any right to exercise or
transfer any such right.

     At any time after a person or a group becomes an Acquiring Person, the
Board of Directors of the Company may exchange all or part of the then
outstanding Rights (other than Rights that have become null and void and
nontransferable as described above) for consideration per Right consisting of
one-half of the securities that otherwise would have been issuable to the holder
of each Right upon exercise thereof. The Board of Directors of the Company may
also issue, in substitution for Preferred Shares, Common Shares having an
equivalent market value to the Preferred Shares if, at such time, the Company
has a sufficient number of Common Shares issued but not outstanding or
authorized but unissued.

     At any time prior to the earlier of (i) such time as a person becomes an
Acquiring Person and (ii) the Expiration Date, the Board of Directors of the
Company may redeem the Rights in whole, but not in part, at a price (in cash or
Common Shares or other securities of the Company deemed by the Board of
Directors to be at least equivalent in value) of $.01 per Right (the "Redemption
Price").

     Immediately upon the action of the Board of Directors of the Company
electing to redeem the Rights, the Company shall make an announcement thereof,
and, upon such election, the right to exercise the Rights will terminate and the
only right of the holders of Rights will be to receive the Redemption Price.




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     Until a Right is exercised, the holder thereof, as such, will have no
rights therefrom as a stockholder of the Company, including, without limitation,
the right to vote or to receive dividends. At any time prior to the Distribution
Date, the Company may, without the approval of any holder of the Rights,
supplement or amend any provision of the Rights Agreement (including the date on
which the Distribution Date shall occur, the time during which the Rights may be
redeemed or the terms of the Preferred Shares), except that no supplement or
amendment shall be made which reduces the Redemption Price or provides for an
earlier Expiration Date.

         The Rights have certain antitakeover effects. The Rights will cause
substantial dilution to a person or group that attempts to acquire the Company
without conditioning the offer on substantially all the Rights being acquired.
The Rights will not interfere with any merger or other business combination or
with a third party approved by the Board of Directors of the Company since the
Board of Directors of the Company may, at its option, at any time prior to any
person becoming an Acquiring Person, redeem all but not less than all of the
then outstanding Rights at the Redemption Price.

     THE FOREGOING DESCRIPTION OF THE RIGHTS DOES NOT PURPORT TO BE COMPLETE AND
IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO THE RIGHTS AGREEMENT, THE
CERTIFICATE OF DESIGNATION OF SERIES A PARTICIPATING CUMULATIVE PREFERRED STOCK
AND THE FORM OF RIGHT CERTIFICATE, EACH OF WHICH IS INCORPORATED HEREIN BY
REFERENCE.

ITEM 2.         EXHIBITS.

 *3.1      Certificate of Incorporation of Aspen Technology, Inc.

**3.1A     Certificate of Designation of Series A Participating Cumulative
           Preferred Stock of Aspen Technology, Inc.

 *3.2      By-Laws of Aspen Technology, Inc.

 *4.1      Rights Agreement dated as of March 12, 1998 between Aspen Technology,
           Inc. and American Stock Transfer and Trust Company, as Rights Agent

**4.3      Form of Right Certificate

 *         Incorporated by reference to the corresponding Exhibit to the
           Registrant's Current Report on Form 8-K dated March 26, 1998.

**         Incorporated by reference to the corresponding Exhibit to the
           Registrant's Form 10-Q dated May 15, 1998.





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                                    SIGNATURE

         Pursuant to the requirements of Section 12 of the Securities Exchange
Act of 1934, the registrant has duly caused this registration statement to be
signed on its behalf by the undersigned, thereunto duly authorized.

                                      ASPEN TECHNOLOGY, INC.

Dated: June 10, 1998                  By:  /s/ Mary A. Palermo
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                                          Mary A. Palermo 
                                          Executive Vice President, Finance and
                                          Chief Financial Officer




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