Exhibit 5.1
                               ________, 1998



XOOM.com, Inc.
300 Montgomery Street
3rd Floor
San Francisco, CA  94104


Ladies and Gentlemen:  


        At your request, we have examined the Registration Statement on Form 
S-1 of XOOM.com, Inc., a Delaware corporation (the "Company"), filed with the
Securities and Exchange Commission (the "Registration Statement") on August
28, 1998, relating to the registration under the Securities Act of 1933, as
amended, of up to 3,450,000 shares of the Company's common stock, $.0001 par
value (the "Stock"), all of which are authorized but unissued stock to be
offered and sold by the Company (including up to 450,000 shares subject to the
underwriters' over-allotment option). The Stock is to be sold to the
underwriters named in the Registration Statement for resale to the public. 

        As counsel to the Company, we have examined the proceedings taken by
the Company in connection with the issuance and sale by the Company of up to
3,450,000 shares of Stock.

        We are of the opinion that the shares of Stock to be offered and sold
by the Company have been duly authorized and, when issued and sold by the
Company in the manner described in the Registration Statement and in
accordance with the resolutions adopted by the Board of Directors of the
Company, will be legally issued, fully paid and nonassessable.

        We consent to the use of this opinion as an exhibit to the
Registration Statement and further consent to all references to us in the
Registration Statement, the prospectus constituting a part thereof and any
amendments thereto. 

                        Very truly yours,


                        Morrison & Foerster LLP