EXHIBIT 5.1

November 22, 2004

Accelrys, Inc.
10188 Telesis Court, Suite 100
San Diego, California 92121

Ladies and Gentlemen:

        You have requested our opinion with respect to certain matters in connection with the filing by Accelrys, Inc., a Delaware corporation (the "Company") of a Registration Statement on Form S-8 (the "Registration Statement") with the Securities and Exchange Commission, covering the registration of an aggregate of 750,000 shares of the Company's Common Stock, $0.0001 par value (the "Shares"), for issuance pursuant to the Company's 2004 New Hire Equity Incentive Plan (the "Plan").

        In connection with this opinion, we have examined and relied upon the Registration Statement and related prospectus, the Plan, the forms of option agreements and offering documents, as applicable, under the Plan, the Company's Amended and Restated Certificate of Incorporation, as amended, and Bylaws, and the originals or copies certified to our satisfaction of such records, documents, certificates, memoranda and other instruments as we deem necessary or appropriate to enable us to render the opinion expressed below. 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, when sold and issued in accordance with the Plan, the Registration Statement and the related prospectus, will be validly issued, fully paid, and nonassessable (except as to shares that may be issued pursuant to certain deferred payment arrangements, which will be fully paid and nonassessable when such deferred payments are made in full).

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

Very truly yours,

COOLEY GODWARD LLP

By:
/s/ STEVEN M. PREZESMICKI
Steven M. Prezesmicki