<PAGE> 1
Filed Pursuant to Rule 424(b)(3)
Registration No. 333-68789
PROSPECTUS SUPPLEMENT NO. 1
TO PROSPECTUS DATED JANUARY 6, 1999
1,329,698 SHARES
ASPEN TECHNOLOGY, INC.
COMMON STOCK
This Prospectus Supplement supplements the information we provided in
our January 6, 1999 Prospectus relating to our common stock. This Prospectus
Supplement is not complete without the Prospectus, and we have not authorized
anyone to deliver or use this Prospectus Supplement without the Prospectus.
In this Prospectus Supplement, we use capitalized terms that we defined
in the Prospectus. You should read the Prospectus to understand those terms.
Unless we indicate otherwise, the information in this Prospectus Supplement is
as of January 27, 1999.
We are providing this Prospectus Supplement to delete the information
regarding Donald E. Shobrys in the table under the caption "Selling
Stockholders" in the Prospectus and to replace that information with the
following:
<TABLE>
<CAPTION>
SHARES TO BE
SHARES BENEFICIALLY OWNED
BENEFICIALLY OWNED NUMBER AFTER OFFERING IF
PRIOR TO OFFERING (1) OF SHARES ALL SHARES SOLD (1)
--------------------- BEING -----------------------
NAME NUMBER PERCENT OFFERED NUMBER PERCENT
- -------- ---------- -------- --------- ----------- ---------
<S> <C> <C> <C> <C> <C>
Donald E. Shobrys.............................. 208,068 * 208,068 -- --
Massachusetts Institute of Technology.......... 10,000 * 10,000 -- --
</TABLE>
- ----------
* Percentage of shares beneficially owned is less than 1.0%.
(1) Beneficial ownership is determined in accordance with the rules of the
Securities and Exchange Commission and generally includes voting or
investment power with respect to securities. Except as indicated, each of
the selling stockholders possesses sole voting and investment power with
respect to all of the shares of common stock owned by them, subject to
community property laws where applicable. For purposes of this Prospectus
Supplement only, we have calculated this percentage on the basis of
24,926,493 shares of common stock outstanding on January 21, 1999.
THE DATE OF THIS PROSPECTUS SUPPLEMENT IS FEBRUARY 4, 1999.
