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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                            ------------------------
 
                                  FORM 10-K/A
 
(MARK ONE)
 
[X]  ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE
     ACT OF 1934
 
     FOR THE FISCAL YEAR ENDED DECEMBER 31, 1997
 
                                       OR
 
[ ]  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES
     EXCHANGE ACT OF 1934
 
     FOR THE TRANSITION PERIOD FROM         TO
 
                        COMMISSION FILE NUMBER: 0-26310
 
                      NETSCAPE COMMUNICATIONS CORPORATION
             (Exact name of registrant as specified in its charter)
 
               DELAWARE                               94-3200270
   (State or other jurisdiction of       (I.R.S. Employer Identification No.)
    incorporation or organization)
 
           501 EAST MIDDLEFIELD ROAD, MOUNTAIN VIEW, CALIFORNIA 94043
              (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES) (ZIP CODE)
 
       Registrant's telephone number, including area code: (650) 254-1900
                            ------------------------
 
        Securities registered pursuant to Section 12(b) of the Act: NONE
 
          Securities registered pursuant to Section 12(g) of the Act:
 
                    COMMON STOCK, PAR VALUE $.0001 PER SHARE
                                (Title of Class)
 
    Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
Registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.    Yes X   No _
 
    Indicate by check mark if disclosure of delinquent filers pursuant to Item
405 of Regulation S-K is not contained herein, and will not be contained, to the
best of Registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K. [ ]
 
    As of March 9, 1998, there were 98,501,803 shares of the Registrant's common
stock outstanding. The aggregate market value of such shares held by
non-affiliates of the Registrant (based upon the closing sale price of such
shares on the Nasdaq National Market on March 9, 1998) was approximately
$1,276,143,576. Shares of the Registrant's common stock held by each executive
officer and director and by each entity that owns 5% or more of the Registrant's
outstanding common stock have been excluded in that such persons may be deemed
to be affiliates. This determination of affiliate status is not necessarily a
conclusive determination for other purposes.
 
                      DOCUMENTS INCORPORATED BY REFERENCE
 
    Certain sections of the Registrant's definitive Proxy Statement for the 1998
Annual Meeting of Stockholders to be held on May 29, 1998 are incorporated by
reference in Part III of this Form 10-K/A to the extent stated herein.
 
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    Netscape's annual report on Form 10-K for the fiscal year ended December 31,
1997, unintentionally omitted the signature on the page entitled "REPORT OF
ERNST & YOUNG LLP, INDEPENDENT AUDITORS." A signed copy of such report is set
forth on the following page.
<PAGE>
               REPORT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS
 
The Board of Directors and Stockholders
 
Netscape Communications Corporation
 
    We have audited the accompanying consolidated balance sheets of Netscape
Communications Corporation as of December 31, 1997 and 1996, and the related
consolidated statements of operations, stockholders' equity, and cash flows for
each of the three years in the period ended December 31, 1997. Our audits also
included the financial statement schedule listed in the Index at Item 14(a).
These financial statements and schedule are the responsibility of Netscape's
management. Our responsibility is to express an opinion on these financial
statements and schedule based on our audits.
 
    We conducted our audits in accordance with generally accepted auditing
standards. Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of material
misstatement. An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements. An audit also includes
assessing the accounting principles used and significant estimates made by
management, as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.
 
    In our opinion, the consolidated financial statements referred to above
present fairly, in all material respects, the consolidated financial position of
Netscape Communications Corporation at December 31, 1997 and 1996, and the
consolidated results of its operations and its cash flows for each of the three
years in the period ended December 31, 1997, in conformity with generally
accepted accounting principles. Also, in our opinion, the related financial
statement schedule, when considered in relation to the basic financial
statements taken as a whole, presents fairly in all material respects the
information set forth therein.
 
                                          /s/ ERNST & YOUNG LLP
 
Palo Alto, California
January 23, 1998, except for Note 14,
  as to which the date is March 25, 1998