SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C. 20549

                                   FORM 8-K

                     RELATING TO ADOPTION OF A RIGHTS PLAN


                    PURSUANT TO SECTION 13 OR 15(d) OF THE
                        SECURITIES EXCHANGE ACT OF 1934

      Date of Report (Date of earliest event reported): October 21, 1999


                           WIND RIVER SYSTEMS, INC.
            (Exact name of registrant as specified in its charter)


                                   DELAWARE
                (State or other jurisdiction of incorporation)



            0-21342                                        94-2873391
     (Commission File No.)                     (IRS Employer Identification No.)



                              500 WIND RIVER WAY
                              ALAMEDA, CA 94501
             (Address of principal executive offices and zip code)



      Registrant's telephone number, including area code: (510) 748-4100


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



ITEM 5.  OTHER EVENTS.

         On October 21, 1999, the Board of Directors of WIND RIVER SYSTEMS, INC.
(the "Company") approved the adoption of a Share Purchase Rights Plan
(the "Plan"). Terms of the Plan provide for a dividend distribution of one
preferred share purchase right (a "Right") for each outstanding share of
common stock, par value $.001 per share (the "Common Shares"), of the
Company. The dividend is payable on November 15, 1999 (the "Record Date") to
the stockholders of record on that date. Each Right entitles the registered
holder to purchase from the Company one one-hundredth of a share of Series A
Junior Participating Preferred Stock, par value $.001 per share (the
"Preferred Shares"), at a price of $160.00 per one one-hundredth of a
Preferred Share (the "Purchase Price"), subject to adjustment. Each one
one-hundredth of a share of Preferred Shares has designations and powers,
preferences and rights, and the qualifications, limitations and restrictions
which make its value approximately equal to the value of a Common Share. The
description and terms of the Rights are set forth in a Rights Agreement (the
"Rights Agreement"), dated as of October, 1999 entered into between the
Company and American Stock Transfer and Trust Company, as rights agent (the
"Rights Agent").

         Initially, the Rights will be evidenced by the stock certificates
representing the Common Shares then outstanding, and no separate Right
Certificates, as defined, will be distributed. Until the earlier to occur of
(i) the date of a public announcement that a person, entity or group of
affiliated or associated persons have acquired beneficial ownership of 15% or
more of the outstanding Common Shares (an "Acquiring Person") or
(ii) 10 business days (or such later date as may be determined by action of
the Board of Directors prior to such time as any person or entity becomes an
Acquiring Person) following the commencement of, or announcement of an
intention to commence, a tender offer or exchange offer the consummation of
which would result in any person or entity becoming an Acquiring Person (the
earlier of such dates being called the "Distribution Date"), the Rights will
be evidenced, with respect to any of the Common Share certificates
outstanding as of the Record Date, by such Common Share certificate with or
without a copy of the Summary of Rights, which is included in the Rights
Agreement as Exhibit C thereof (the "Summary of Rights").

         Until the Distribution Date, the Rights will be transferable with
and only with the Common Shares. Until the Distribution Date (or earlier
redemption or expiration of the Rights), new Common Share certificates issued
after the Record Date, upon transfer or new issuance of Common Shares, will
contain a notation incorporating the Rights Agreement by reference. Until the
Distribution Date (or earlier redemption or expiration of the Rights), the
surrender or transfer of any certificates for Common Shares outstanding as of
the Record Date, even without such notation or a copy of the Summary of
Rights being attached thereto, will also constitute the transfer of the
Rights associated with the Common Shares represented by such certificate. 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 such separate Right Certificates alone will evidence the Rights.

         The Rights are not exercisable until the Distribution Date. The
Rights will expire on October 22, 2001 (the "Final Expiration Date"), unless
the Rights are earlier redeemed or exchanged by the Company, in each case, as
described below.


                                       1.



         The Purchase Price payable, and the number of Preferred Shares or
other securities or other property, upon exercise of the Rights are subject
to adjustment from time to time to prevent dilution (i) in the event of a
stock dividend on, or a subdivision, combination or reclassification of, the
Preferred Shares, (ii) upon the grant to holders of the Preferred Shares of
certain rights or warrants to subscribe for or purchase Preferred Shares at a
price, or securities convertible into Preferred Shares with a conversion
price, less than the then current market price of the Preferred Shares or
(iii) upon the distribution to holders of the Preferred Shares of evidences
of indebtedness or assets (excluding regular periodic cash dividends paid out
of earnings or retained earnings or dividends payable in Preferred Shares) or
of subscription rights or warrants (other than those referred to above). The
exercise of Rights for Preferred Shares is at all times subject to the
availability of a sufficient number of authorized but unissued Preferred
Shares.

         The number of outstanding Rights and the number of one
one-hundredths of a Preferred Share issuable upon exercise of each Right are
also subject to adjustment in the event of a stock split of the Common Shares
or a stock dividend on the Common Shares payable in Common Shares or
subdivisions, consolidation or combinations of the Common Shares occurring,
in any case, prior to the Distribution Date.

         Preferred Shares purchasable upon exercise of the Rights will not be
redeemable. Each Preferred Share will be entitled to a minimum preferential
quarterly dividend payment of $1.00 but will be entitled to an aggregate
dividend of 100 times the dividend declared per Common Share. In the event of
liquidation, the holders of the Preferred Shares would be entitled to a
minimum preferential liquidation payment of $100 per share, but would be
entitled to receive an aggregate payment equal to 100 times the payment made
per Common Share. Each Preferred Share will have 100 votes, voting together
with the Common Shares. Finally, in the event of any merger, consolidation or
other transaction in which Common Shares are exchanged, each Preferred Share
will be entitled to receive 100 times the amount of consideration received
per Common Share. These rights are protected by customary anti-dilution
provisions. Because of the nature of the Preferred Shares' dividend and
liquidation rights, the value of one one-hundredth of a Preferred Share
should approximate the value of one Common Share. The Preferred Shares would
rank junior to any other series of the Company's preferred stock.

         In the event that any person or group of affiliated or associated
persons becomes an Acquiring Person, proper provision shall be made so that
each holder of a Right, other than Rights beneficially owned by the Acquiring
Person and its associates and affiliates (which will thereafter be void),
will for a 60-day period have the right to receive upon exercise that number
of Common Shares having a market value of two times the exercise price of the
Right (or, if such number of shares is not and cannot be authorized, the
Company may issue Preferred Shares, cash, debt, stock or a combination
thereof in exchange for the Rights). This right will terminate 60 days after
the date on which the Rights become nonredeemable (as described below),
unless there is an injunction or similar obstacle to exercise of the Rights,
in which event this right will terminate 60 days after the date on which the
Rights again become exercisable.

         Generally, under the Plan, an "Acquiring Person" shall not be deemed
to include (i) the Company, (ii) a subsidiary of the Company, (iii) any
employee benefit or compensation plan of the Company, or (iv) any entity
holding Common Shares for or pursuant to the terms of any such employee
benefit or compensation plan. In addition, except under limited
circumstances, no


                                       2.



person or entity shall become an Acquiring Person as the result of the
acquisition of Common Shares by the Company which, by reducing the number of
shares outstanding, increases the proportionate number of shares beneficially
owned by such person or entity to 15% or more of the Common Shares then
outstanding. Further, except under certain circumstances, no person shall
become an Acquiring Person due to the acquisition of Common Shares directly
from the Company.

         In the event that the Company is acquired in a merger or other
business combination transaction or 50% or more of its consolidated assets or
earning power are sold to an Acquiring Person, its associates or affiliates
or certain other persons in which such persons have an interest, proper
provision will be made so that each holder of a Right will thereafter have
the right to receive, upon the exercise thereof at the then current exercise
price of the Right, that number of shares of common stock of the acquiring
company which at the time of such transaction will have a market value of two
times the exercise price of the Right.

         At any time after an Acquiring Person becomes an Acquiring Person
and prior to the acquisition by such Acquiring Person of 50% or more of the
outstanding Common Shares, the Board of Directors of the Company may exchange
the Rights (other than Rights owned by such person or group which have become
void), in whole or in part, at an exchange ratio of one Common Share, or one
one-hundredth of a Preferred Share, per Right (or, at the election of the
Company, the Company may issue cash, debt, stock or a combination thereof in
exchange for the Rights), subject to adjustment.

         With certain exceptions, no adjustment in the Purchase Price will be
required until cumulative adjustments require an adjustment of at least 1% in
such Purchase Price. No fractional Preferred Shares will be issued (other
than fractions which are integral multiples of the number of one
one-hundredths of a Preferred Share issuable upon the exercise of one Right,
which may, at the election of the Company, be evidenced by depositary
receipts), and in lieu thereof, an adjustment in cash will be made based on
the market price of the Preferred Shares on the last trading day prior to the
date of exercise.

         At any time prior to the earliest of (i) the day of the first public
announcement that a person has become an Acquiring Person or (ii) the Final
Expiration Date, the Board of Directors of the Company may redeem the Rights
in whole, but not in part, at a price of $0.01 per Right (the "Redemption
Price"). Following the expiration of the above periods, the Rights become
nonredeemable. Immediately upon any redemption of the Rights, the right to
exercise the Rights will terminate and the only right of the holders of
Rights will be to receive the Redemption Price.

         The terms of the Rights may be amended by the Board of Directors of
the Company without the consent of the holders of the Rights, except that
from and after such time as the rights are distributed no such amendment may
adversely affect the interest of the holders of the Rights excluding the
interests of an Acquiring Person.

         Until a Right is exercised, the holder thereof, as such, will have
no rights as a stockholder of the Company, including, without limitation, the
right to vote or to receive dividends.


                                       3.



         The Rights have certain anti-takeover effects. The Rights will cause
substantial dilution to a person or group that attempts to acquire the
Company on terms not approved by the Company's Board of Directors. The Rights
should not interfere with any merger or other business combination approved
by the Board of Directors since the Rights may be amended to permit such
acquisition or redeemed by the Company at $0.01 per Right prior to the
earliest of (i) the time that a person or group has acquired beneficial
ownership of 15% or more of the Common Shares or (ii) the final expiration
date of the rights.

ITEM 7.  EXHIBITS.



       
     4.1  Registrant's Certificate of Incorporation (including Certificate of
          Designation of Series A Junior Participating Preferred Stock.)

     99.1 Press Release, dated as of October 28, 1999 entitled "Wind River
          Systems, Inc. Adopts Stockholder Rights Plan."

     99.2 Rights Agreement dated as of October 22, 1999 among Wind River
          Systems, Inc. and American Stock Transfer and Trust Company.

     99.3 Form of Rights Certificate.




                                       4.



                                   SIGNATURE

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


                                       WIND RIVER SYSTEMS, INC.


Dated: November 4, 1999                By: /s/ Richard W. Kraber
                                           -------------------------------------
                                               Richard W. Kraber
                                               Chief Financial Officer


                                       5.



                               INDEX TO EXHIBITS



       
     4.1  Registrant's Certificate of Incorporation (including Certificate of
          Designation of Series A Junior Participating Preferred Stock.)

     99.1 Press Release, dated as of October 28, 1999 entitled "Wind River
          Systems, Inc. Adopts Stockholder Rights Plan."

     99.2 Rights Agreement dated as of October 22, 1999 among Wind River
          Systems, Inc. and American Stock Transfer and Trust Company.

     99.3 Form of Rights Certificate.




                                       6.