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                                                                     EXHIBIT 5.1

                        WILSON SONSINI GOODRICH & ROSATI
                               650 PAGE MILL ROAD
                               PALO ALTO, CA 94304
                                 (650) 493-9300

                                November 9, 2000


Sun Microsystems, Inc.
901 San Antonio Road
Palo Alto, CA  94303

     RE:  REGISTRATION STATEMENT ON FORM S-8

Ladies and Gentlemen:

     We have acted as counsel to Sun Microsystems, Inc., a Delaware corporation
(the "Company" or "You") and have examined the Registration Statement on Form
S-8 (the "Registration Statement") to be filed by the Company with the
Securities and Exchange Commission on or about November 10, 2000 in connection
with the registration under the Securities Act of 1933, as amended, of 7,000,000
additional shares of the Company's Common Stock, par value $0.00067 per share
(the "Shares"), reserved for issuance under the 1990 Long-Term Equity Incentive
Plan.

     As your legal counsel, we have examined the proceedings taken and are
familiar with the proceedings to be taken in connection with the sale and
issuance of said Shares under the Plan. It is our opinion that the additional
Shares, when issued and sold in the manner referred to in the Plan and pursuant
to the agreements which accompany the Plan, the Shares will be legally and
validly issued, fully paid and nonassessable.

     We consent to the use of this opinion as an exhibit to the Registration
Statement and further consent to the use of our name wherever appearing in the
Registration Statement and any amendments thereto.

                                   Sincerely,

                                   WILSON SONSINI GOODRICH & ROSATI
                                   Professional Corporation

                                   /s/ WILSON SONSINI GOODRICH & ROSATI