Exhibit 5.1

                           [COOLEY GODWARD LETTERHEAD]

September 28, 2000

Wind River Systems, Inc.
500 Wind River Way
Alameda, CA  94501

Ladies and Gentlemen:

You have requested our opinion with respect to certain matters in connection
with the filing by Wind River Systems, Inc. (the "Company") of a Registration
Statement on Form S-8 (the "Registration Statement") with the Securities and
Exchange Commission covering the offering of up to 1,500,000 shares of the
Company's common stock, $.001 par value ("Common Stock"), pursuant to the 1993
Employee Stock Purchase Plan, as amended (the "Purchase Plan"), and 2,500,000
shares pursuant to the 1998 Non-Officer Stock Option Plan (together with the
Purchase Plan, the "Plans").

In connection with this opinion, we have examined the Registration Statement,
your Certificate of Incorporation and Bylaws, as amended, and such other
documents, records, certificates, memoranda and other instruments as we deem
necessary as a basis for this opinion. We have assumed the genuineness and
authenticity of all documents submitted to us as originals, the conformity to
originals of all documents submitted to us as copies thereof, and the due
execution and delivery of all documents where due execution and delivery are a
prerequisite to the effectiveness thereof.

On the basis of the foregoing, and in reliance thereon, we are of the opinion
that the shares of Common Stock, when sold and issued in accordance with the
Plans, the Registration Statement and the related prospectus will be validly
issued, fully paid, and nonassessable.

We consent to the filing of this opinion as an exhibit to the Registration
Statement.

Very truly yours,

COOLEY GODWARD LLP


By:      /s/ Andrea Vachss
     ----------------------------
         Andrea Vachss, Esq.