<PAGE>   1
 
   AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON DECEMBER 14, 1998
 
                                                     REGISTRATION NO.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                            ------------------------
 
                                  FORM S-8/S-3
                             REGISTRATION STATEMENT
(INCLUDING REGISTRATION OF SHARES FOR RESALE BY MEANS OF A FORM S-3 PROSPECTUS)
                                     UNDER
                           THE SECURITIES ACT OF 1933
 
                                 SYNOPSYS, INC.
               (EXACT NAME OF REGISTRANT AS SPECIFIED IN CHARTER)
 
<TABLE>
<S>                                                 <C>
                     DELAWARE                                           56-1546236
             (STATE OF INCORPORATION)                      (I.R.S. EMPLOYER IDENTIFICATION NO.)
</TABLE>
 
                            700 E. MIDDLEFIELD ROAD
                            MOUNTAIN VIEW, CA 94043
                    (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)
 
      EVEREST DESIGN AUTOMATION INC. 1997 STOCK OPTION/STOCK ISSUANCE PLAN
                 FOUNDER'S RESTRICTED STOCK PURCHASE AGREEMENTS
           EVEREST DESIGN AUTOMATION INC. NON-STATUTORY STOCK OPTIONS
                            (FULL TITLE OF THE PLAN)
 
                                AART J. DE GEUS
                     PRESIDENT AND CHIEF EXECUTIVE OFFICER
                                 SYNOPSYS, INC.
                            700 E. MIDDLEFIELD ROAD
                            MOUNTAIN VIEW, CA 94043
                                 (650) 962-5000
(NAME, ADDRESS, AND TELEPHONE NUMBER, INCLUDING AREA CODE, OF AGENT FOR SERVICE)
 
                                    COPY TO:
                           THOMAS C. DEFILIPPS, ESQ.
                        WILSON SONSINI GOODRICH & ROSATI
                            PROFESSIONAL CORPORATION
                               650 PAGE MILL ROAD
                            PALO ALTO, CA 94304-1050
                                 (415) 493-9300
 
                        CALCULATION OF REGISTRATION FEE
 
<TABLE>
<S>                                          <C>                   <C>                <C>                   <C>
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                                                   MAXIMUM         PROPOSED MAXIMUM     PROPOSED MAXIMUM
TITLE OF SECURITIES                              AMOUNT TO BE       OFFERING PRICE     AGGREGATE OFFERING        AMOUNT OF
TO BE REGISTERED                                REGISTERED(1)          PER SHARE             PRICE            REGISTRATION FEE
--------------------------------------------------------------------------------------------------------------------------------
Common Stock, $0.01 par value
  Issued under Restricted Stock Purchase
    Agree-
    ments of Everest Design Automation
    Inc. ..................................   441,180 shares(3)       $52.6875(2)        $23,244,671.25          $6,462.02
  Issued under the Everest Design
    Automation Inc. 1997 Stock Option/Stock
    Issuance Plan..........................   152,654 shares(3)       $52.6875(2)        $ 8,042,957.63          $2,235.94
  Issued under Everest Design Automation
    Inc. Non-Statutory Stock Options.......     22,059 shares         $52.6875(2)        $ 1,162,233.56          $  323.10
  To be issued under the Everest Design
    Automation Inc. 1997 Stock Option/Stock
    Issuance Plan..........................   111,357 shares(3)       $ 4.3200(4)        $  481,062.24           $  133.74
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         Total.............................     727,250 shares                           $32,930,924.68          $9,154.80
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</TABLE>
 
(1) For the sole purpose of calculating the registration fee, the number of
    shares to be registered under this Registration Statement has been broken
    down into four subtotals.
 
(2) Computed in accordance with Rule 457(h) under the Securities Act. Such
    computation is based on the average of the high and low prices reported on
    the Nasdaq National Market on December 10, 1998.
 
(3) Certain of such shares are subject to vesting.
 
(4) Computed in accordance with Rules 457(h) and 457(i) under the Securities
    Act. Such computation is based on the weighted average exercise price of
    $0.29 per share covering authorized but unissued shares under Everest Design
    Automation Inc.'s 1997 Stock Option/Stock Issuance Plan.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
<PAGE>   2
 
PROSPECTUS
 
Synopsys, Inc.
700 East Middlefield Road
Mountain View, CA 94043
Telephone Number: (650) 962-5000
 
                                 727,250 SHARES
 
                                      LOGO
 
                                  COMMON STOCK
 
                            ------------------------
 
     These shares may be offered and sold from time to time by certain
stockholders of the Company identified in this prospectus. See "Selling
Stockholders." The selling stockholders acquired the shares on November 20, 1998
in connection with the acquisition by Synopsys, Inc. ("Synopsys") of Everest
Design Automation Inc. ("Everest") pursuant to an Agreement of Merger and Plan
of Reorganization by and among Synopsys, Tenzing Acquisition Corporation, a
Delaware corporation and a wholly-owned subsidiary of Synopsys, and Everest,
dated as of October 26, 1998 (the "Merger Agreement").
 
     The selling stockholders will receive all of the net proceeds from the sale
of the shares. These stockholders will pay all underwriting discounts and
selling commissions, if any, applicable to the sale of the shares. Synopsys will
not receive any proceeds from the sale of the shares.
 
     YOU SHOULD CONSIDER CAREFULLY THE RISK FACTORS BEGINNING ON PAGE 3 OF THIS
PROSPECTUS BEFORE PURCHASING ANY OF THE COMMON STOCK.
 
     Synopsys' common stock is quoted on the Nasdaq National Market under the
symbol "SNPS." On December 10, 1998, the last reported sale of the common stock
was $51.625 per share.
 
                            ------------------------
 
     The Securities and Exchange Commission and state securities regulators have
not approved or disapproved these securities, or determined if this prospectus
is truthful or complete. Any representation to the contrary is a criminal
offense.
 
                            ------------------------
 
                               December 14, 1998
<PAGE>   3
 
                               TABLE OF CONTENTS
 
                                   PROSPECTUS
 
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                                                              PAGE
                                                              ----
<S>                                                           <C>
Synopsys, Inc...............................................    3
Risk Factors................................................    3
Where to Find More Information About Synopsys...............    7
Information Incorporated by Reference.......................    7
Selling Stockholders........................................    9
Plan of Distribution........................................   10
Indemnification of Directors and Officers...................   12
</TABLE>
 
     You should rely only on the information contained in this prospectus. We
have not authorized anyone to provide you with information different from that
contained in this prospectus. The selling stockholders are offering to sell, and
seeking offers to buy, shares of Synopsys common stock only in jurisdictions
where offers and sales are permitted. The information contained in this
prospectus is accurate as of the date of this prospectus, regardless of the time
of delivery of this prospectus or any sale of the shares.
 
     In this prospectus, unless indicated otherwise, "Synopsys," the "Company,"
"we," "us" and "our" refer to Synopsys, Inc. and its subsidiaries.
 
                          FORWARD LOOKING INFORMATION
 
     This prospectus, including the information incorporated by reference
herein, contains forward-looking statements within the meaning of Section 27A of
the Securities Act of 1933, as amended (the "Securities Act") and Section 21E of
the Exchange Act of 1934 (the "Exchange Act"). Our actual results could differ
materially from those projected in the forward-looking statements as a result of
the risk factors set forth below. In addition, please review the sections
captioned "Management's Discussion and Analysis of Financial Condition and
Results of Operations" in our annual report on Form 10-K for the fiscal year
ended September 30, 1997, and our quarterly reports on form 10-Q for the
quarters ended July 4, 1998, April 4, 1998 and January 3, 1998, which reports
are incorporated herein by reference and such section of any subsequently filed
Exchange Act reports. In connection with forward-looking statements which appear
in these disclosures, prospective purchasers of the shares offered hereby should
carefully consider the factors set forth in this prospectus under "Risk
Factors."
 
                                        2
<PAGE>   4
 
                                 SYNOPSYS, INC.
 
     Synopsys develops, markets, and supports electronic design automation
("EDA") products for designers of integrated circuits ("ICs") and electronic
systems. Synopsys offers a range of design tools, verification tools and
systems, design reuse products and physical design tools intended to improve
designers' productivity by offering improved time to market, reduced development
and manufacturing costs, and enhanced design quality of results when compared to
earlier generations of EDA products. Synopsys also provides training, support
and consulting services for its customers.
 
                                  RISK FACTORS
 
     You should carefully consider the risks described below before making an
investment decision. The risks and uncertainties described below are not the
only ones facing our company. The risk factors set forth herein reflect those
risks known to management as of the date of this prospectus and which management
believes could be material to our business, operating results and financial
condition. Additional risks and uncertainties not presently known to us or that
we currently deem immaterial may also impair our business operations. Such risk
factors may change over time and may differ materially from those set forth
herein. Prospective investors are cautioned to review, in addition to these risk
factors, the risk factors contained in "Management's Discussion and Analysis of
Financial Condition and Results of Operations" contained in our most recent
Annual Report on Form 10-K or Quarterly Report on Form 10-Q as well as the
additional information contained in such reports and our other reports and
filings with the Securities and Exchange Commission.
 
     If any of the following risks actually occur, our business, financial
condition or results of operations could be materially adversely affected. In
such case, the trading price of our common stock could decline and you may lose
all or part of your investment.
 
     This prospectus contains forward-looking statements that involve risks and
uncertainties. Our actual results could differ materially from those anticipated
in such forward-looking statement as a result of a variety of factors, including
those set forth in the following risk factors or elsewhere in, or incorporated
by reference into, this prospectus.
 
POTENTIAL EARNINGS FLUCTUATIONS
 
     We attempt to plan our business to achieve quarter-to-quarter revenue and
earnings growth. Achieving predictable revenue and earnings growth is difficult.
Quarterly revenue and earnings are affected by many factors, including customer
product demand, product license terms, the size of our backlog, and the timing
of revenue recognition on products and services sold. The following factors
could affect our revenues and earnings per share in a particular quarter or over
several quarterly or annual periods:
 
     - Our orders are seasonal. Historically, our first fiscal quarter ending
       December 31 is our weakest, and may have a book-to-bill ratio below one.
 
     - Our products are complex, and before buying them potential customers
       spend a great deal of time reviewing and testing them. This is
       particularly true if they are new customers or current customers
       purchasing a new product or switching from a competitor's product. The
       sales cycle does not necessarily match quarterly periods, and if by the
       end of any quarter our sales force has not sold enough new licenses, our
       orders and revenues could be substantially reduced.
 
     - Like many companies in the software industry, we receive a
       disproportionate volume of orders in the last week of a quarter, and
       recognize a disproportionate amount of revenue in the last week of a
       quarter. In addition, the proportion of our business attributable to our
       largest customers is increasing. As a result, if any order, and
       especially a large order, is delayed beyond the end of a fiscal period,
       our orders and revenue for that period could be substantially reduced.
 
                                        3
<PAGE>   5
 
     - The accounting rules we are required to follow only permit us to
       recognize revenue when certain criteria are met. Orders for certain of
       the Company's products and services, including certain time-based product
       licenses, consulting services, and software support, yield revenue (or a
       significant portion thereof) over multiple quarters (often extending
       beyond the current fiscal year) or upon completion of performance rather
       than at the time of sale. In addition, in negotiating a purchase order
       with a customer, we may agree to terms that have the effect of requiring
       deferral of revenue in whole or in part. As a result, it may be difficult
       for us to convert orders, particularly those received late in a quarter,
       or backlog, to revenue in any given quarter. It is therefore possible for
       the Company to fall short in its revenue and/or earnings plan for a given
       quarter even while orders and backlog remain on plan.
 
COMPETITION
 
     The EDA industry is highly competitive. We compete against other EDA
vendors, and with customers' internally developed design tools and internal
design capabilities, for a share of the overall EDA budgets of our customers.
Our competitors include companies that offer a broad range of products and
services, such as Cadence Design Systems, Inc. ("Cadence"), Mentor Graphics,
Inc. ("Mentor") and Avant! Corporation ("Avant!"), as well as companies,
including numerous start-up companies, that offer products focused on a discrete
phase of the IC design process. In order to remain successful against such
competition, we must continue to enhance our current products and bring to
market new products that address the increasingly sophisticated needs of our
customers on a timely and cost-effective basis. We also will have to expand our
ability to offer consulting services. The failure to enhance existing products,
develop and/or acquire new products or to expand our ability to offer such
services would have a material adverse effect on our business, financial
condition and results of operations.
 
     Technology advances and customer requirements are fueling a change in the
nature of competition among EDA vendors. Increasingly, EDA companies compete on
the basis of "design flows" involving a broad range of products (including both
logic and physical design tools) and services rather than on the basis of
individual "point" tools performing a discrete phase of the design process. No
single EDA company currently offers its customers industry-leading products in a
complete design flow. We offer a wide range of logic design tools but currently
offer a relatively limited range of physical design tools. In November 1998 we
acquired Everest, a private company developing physical design software. We will
need to develop or acquire additional physical design tools in order to offer a
complete design flow. We are also attempting to expand our capacity to offer
professional services, but for the foreseeable future will continue to have less
capacity than Cadence to provide such services. The market for physical design
tools is dominated by Cadence and Avant!, both of which are attempting to
complete their design flows. Cadence recently acquired Ambit Design Systems, a
private company offering synthesis and other logic design products, as well as
certain physical design verification products from Lucent Technologies, both of
which will increase the direct competition between Synopsys and Cadence. In
addition, Cadence's acquisition of logic design products may lead to reductions
in purchases of our logic design software by Cadence, which was one of Synopsys'
ten largest customers in fiscal 1998. Avant! also recently acquired a private
company offering logic synthesis software, which will increase the direct
competition between Synopsys and Avant!.
 
SUCCESS OF NON-SYNTHESIS PRODUCTS
 
     Historically, much of the Company's growth has been attributable to the
strength of its logic synthesis products. Opportunities for growth in market
share in this area are limited, and synthesis revenues are expected to grow more
slowly than our target for overall revenue growth. Synthesis and related "design
creation" products account for approximately 45-50% of our revenue. As a result,
in order to meet our revenue plan, non-synthesis design creation products, high
level verification products and deep submicron products and our services
business will have to grow faster than our overall revenue growth target.
 
     Our PrimeTime timing analysis, Formality formal verification, Module
Compiler datapath synthesis and VCS Verilog simulation products are expected to
be among the most important contributors to product revenue growth. These
products have achieved initial customer acceptance, but we will only derive
significant revenue from these products if they are accepted by a broad range of
customers. Product success is difficult to
                                        4
<PAGE>   6
 
predict. The introduction of new products and growth of a market for such
products cannot be assured in a highly competitive environment like EDA. In the
past we, like all companies, have had products that despite initial successes,
have failed to meet our revenue expectations. Expanding our capacity to offer
consulting services and our revenues derived therefrom will require us to
recruit, hire and train a large number of talented people, and to implement
management controls on bidding and executing on services engagements. The
consulting business is significantly different than the software business,
however, and as indicated by recent layoffs announced by Cadence in its service
business, increasing consulting orders and revenue while maintaining an adequate
level of profit can be difficult. There can be no assurance that the Company
will be successful in expanding revenues from existing or new products at the
desired rate or expanding its services business, and the failure to do so would
have a material adverse effect on the Company's business, financial condition
and results of operations.
 
INTEGRATION OF ACQUIRED BUSINESSES
 
     We have acquired or merged with a number of companies in recent years,
including EPIC Design Technology, Inc., Viewlogic Systems, Inc., Systems Science
Inc. and Everest, and as part of our efforts to expand our product and services
offerings we may acquire additional companies in the future. In addition to
direct costs, acquisitions pose a number of risks, including potential dilution
of earnings per share, problems of integrating the acquired products and
employees into our business, the failure to realize expected synergies or cost
savings, the drain on management time for acquisition-related activities,
possible adverse effects on customer buying patterns due to uncertainties
resulting from an acquisition, and assumption of unknown liabilities. While we
attempt to review proposed acquisitions carefully and negotiate terms that are
favorable to the Company, there is no assurance that any individual acquisition
will have the projected effect on the Company's performance.
 
DEPENDENCE ON SEMICONDUCTOR AND ELECTRONICS BUSINESSES
 
     Our business has benefited from the rapid worldwide growth of the
semiconductor industry. Purchases of our products are largely dependent upon the
commencement of new design projects by semiconductor manufacturers and their
customers. The outlook for the semiconductor industry for the remainder of
calendar year 1998 and 1999 is uncertain, owing in part to adverse economic
conditions in Asia and to potential slowing of growth in the United States. A
number of the Company's customers have announced layoffs of their employees or
the suspension of investment plans, and although the Company has not seen a
significant drop-off in demand from these customers, their EDA budgets could be
reduced, alone or as part of overall expense control efforts. In addition, there
have been a number of mergers in the semiconductor and systems industries, which
may reduce the aggregate level of purchases of our products and services by the
merged companies. Slower growth in the semiconductor and systems industries, a
reduced number of design starts, tightening of customers' operating budgets or
continued consolidation among the Company's customers may have a material
adverse effect on our business, financial condition and results of operations.
 
INTERNATIONAL EXPOSURE
 
     In fiscal 1998, international revenue accounted for 39% of our revenue,
after accounting for 41% and 42% of our revenue in fiscal 1997 and 1996,
respectively. We expect that international revenue will continue to account for
a significant portion of our revenue in the future. As a result, the Company's
performance may be negatively affected by changes in foreign currency exchange
rates and changes in regional or worldwide economic or political conditions. In
particular:
 
     - Revenue from sales in Japan during fiscal 1998 was adversely affected by
       the weakness of the yen against the dollar, overall weakness in the
       Japanese economy and the deferral of investments in semiconductor
       facilities and technology by Japanese companies. Continued weakness of
       the Japanese economy during fiscal 1999 is likely to adversely affect
       revenue from Japan during the year. The yen has recently strengthened,
       but the exchange rate for fiscal 1999 remains subject to unpredictable
       fluctuations. Renewed weakness of the yen could adversely affect revenue
       from Japan during fiscal 1999.
                                        5
<PAGE>   7
 
     - Significant declines in the value of the Korean won during fiscal 1998,
       and the subsequent economic crisis had a significant adverse affect on
       our business in Korea during the year, and is likely to continue to
       affect our orders and revenue from Korea in fiscal 1999. Declines in the
       currencies of other countries in the Asia Pacific region, particularly
       Taiwan, have also negatively affected the Company's sales in the region.
       Continued instability in Asian currency markets and weaknesses in Asian
       economies would continue to have an adverse effect on our orders and
       revenues from the Asia Pacific region.
 
RISKS OF JOINT DEVELOPMENT
 
     In February 1996, we entered into a six-year joint development and license
agreement with IBM, pursuant to which the two companies agreed to develop
certain new products. Joint development of products is subject to risks and
uncertainties over and above those affecting internal development. During fiscal
year 1997, the first joint product resulting from the alliance, PrimeTime, was
introduced, and the parties agreed to terminate efforts to develop a product in
one of the product areas covered by the Agreement. A second joint product is
expected to be introduced in January 1999, and development of the fourth product
to be developed under the agreement has been suspended. Synopsys and IBM are
currently discussing the future of the alliance. There can be no assurance that
joint development will continue, or that the products developed by the alliance
will be successful.
 
NEED TO RECRUIT AND RETAIN KEY PERSONNEL
 
     Our success is dependent on technical and other contributions of key
employees. We participate in a dynamic industry, with significant start-up
activity, and our headquarters is in Silicon Valley, where skilled technical,
sales and management employees are in high demand. There is a limited number of
qualified EDA engineers, and the competition for such individuals is intense.
Experience at Synopsys is highly valued in the EDA industry, and our employees
are recruited aggressively by our competitors and by start-up companies. Our
salaries are competitive in the market, but under certain circumstances,
start-up companies can offer more attractive stock option packages. As a result,
we have experienced, and may continue to experience, significant employee
turnover. In addition, there can be no assurance that we can continue to recruit
and retain key personnel. Failure to successfully recruit and retain such
personnel could have a material adverse effect on our business, financial
condition and results of operations.
 
POISON PILL PROVISIONS
 
     The Company has adopted a number of provisions that could have
anti-takeover effects. The Board of Directors has adopted a Preferred Shares
Rights Plan, commonly referred to as a "poison pill." In addition, the Board of
Directors has the authority, without further action by its stockholders, to fix
the rights and preferences of, and issue shares of, authorized but undesignated
shares of Preferred Stock. This provision and other provisions of the Company's
Restated Certificate of Incorporation and Bylaws and the Delaware General
Corporation Law may have the effect of deterring hostile takeovers or delaying
or preventing changes in control or management of the Company, including
transactions in which the stockholders of the Company might otherwise receive a
premium for their shares over then current market prices.
 
YEAR 2000
 
     Synopsys presently believes that we will not experience significant
operational problems arising from the Year 2000 problem (i.e., the inability of
certain computer programs to correctly process date information on or after
January 1, 2000). However, if unforeseen Year 2000 issues arise with respect to
Synopsys products, one or more important customers experiences Year 2000-related
problems that interferes with their purchases of Synopsys products, or we are
not able to identify and fix Year 2000 problems relating to the computer systems
and software we rely on to run our business, we may experience a disruption in
our business, which could have a material adverse impact on our business,
financial condition and results of operations.
 
                                        6
<PAGE>   8
 
CHANGES IN FINANCIAL ACCOUNTING STANDARDS
 
     We prepare our financial statements in conformity with generally accepted
accounting principles ("GAAP"). GAAP are subject to interpretation by the
American Institute of Certified Public Accountants ("AICPA"), the Securities and
Exchange Commission (the "SEC") and various bodies formed to interpret and
create appropriate accounting policies. A change in these policies can have a
significant effect on our reported results, and may even affect our reporting of
transactions completed before a change is announced. Accounting policies
affecting many other aspects of our business, including rules relating to
software revenue recognition, purchase and pooling-of-interests accounting for
business combinations, employee stock purchase plans and stock option grants
have recently been revised or are under review by one or more groups. Changes to
these rules, or the questioning of current practices, may have a significant
adverse affect on our reported financial results or in the way we conduct our
business.
 
     In addition, the preparation of financial statements in conformity with
GAAP requires us to make estimates and assumptions that affect the recorded
amounts of assets and liabilities, disclosure of those assets and liabilities at
the date of the financial statements and the recorded amounts of expenses during
the reporting period. A change in the facts and circumstances surrounding these
estimates could result in a change to the estimates and impact future operating
results.
 
                 WHERE TO FIND MORE INFORMATION ABOUT SYNOPSYS
 
     We file special reports, proxy statements and other information with the
SEC. You may read and copy any document we file at the SEC's public reference
rooms in Washington, D.C., New York, New York and Chicago, Illinois. Please call
the SEC at 1-800-SEC-0330 for further information on the public reference rooms.
Our SEC filings are also available to the public from the SEC's Web site at
http://www.sec.gov.
 
     This prospectus contains information concerning the Company and the sale of
its Common Stock by the Selling Stockholders, but does not contain all the
information set forth in the Registration Statement on Form S-8/S-3 (the
"Registration Statement") which the Company has filed with the SEC under the
Securities Act of 1933, as amended (the "Securities Act"). Statements made in
this Prospectus as to the contents of any referenced contract, agreement or
other document are not necessarily complete, and such statement shall be deemed
qualified in its entirety by reference thereto. The Registration Statement,
including various exhibits, may be obtained upon payment of the fee prescribed
by the SEC, or may be examined without charge at the SEC's office in Washington,
D.C.
 
                     INFORMATION INCORPORATED BY REFERENCE
 
     The SEC allows us to "incorporate by reference" the information we file
with them, which means that we can disclose important information to you by
referring you to those documents that we have previously filed with the SEC or
documents that we will file with the SEC in the future. The information
incorporated by reference is considered to be part of this prospectus, and later
information that we file with the SEC will automatically update and supercede
this information. We incorporate by reference the documents listed below, and
any future filings made with the SEC under Sections 13(a), 13(c), 14 or 15(d) of
the Exchange Act, until the selling stockholders sell all the shares. This
prospectus is part of a Registration Statement we filed with the SEC. The
documents we incorporate by reference are:
 
     (1) Synopsys's Annual Report on Form 10-K for the fiscal year ended
         September 30, 1997;
 
     (2) Synopsys's Quarterly Report on Form 10-Q for the quarter ended July 4,
         1998;
 
     (3) Synopsys's Quarterly Report on Form 10-Q for the quarter ended April 4,
         1998;
 
     (4) Synopsys's Quarterly Report on Form 10-Q for the quarter ended January
         3, 1998;
 
     (5) Synopsys's Current Report on Form 8-K dated November 16, 1998 relating
         to fourth quarter results;
 
                                        7
<PAGE>   9
 
     (6) Synopsys's Current Report on Form 8-K dated December 19, 1997 for the
         acquisition of Viewlogic Systems, Inc.; and
 
     (7) The description of the Synopsys's Common Stock contained in the
         Company's Registration Statement on Form 8-A, No. 000-19807, filed on
         January 24, 1992.
 
     We also incorporate by reference all documents subsequently filed by the
Company pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act,
prior to the filing of a post-effective amendment which indicates that all
securities registered have been sold or which deregisters all securities then
remaining unsold.
 
     Any statement contained in a document incorporated or deemed to be
incorporated by reference herein shall be deemed to be modified or superseded
for purposes of the Registration Statement or this Prospectus to the extent that
a statement contained herein, in a Prospectus Supplement or in any other
document subsequently filed with the Commission which also is or is deemed to be
incorporated by reference herein modifies or supersedes such statement. Any such
statement so modified or superseded shall not be deemed, except as so modified
or superseded, to constitute a part of the Registration Statement or this
Prospectus.
 
     You may request a copy of these filings, at no cost, by writing or
telephoning us at the following address: Synopsys, Inc., 700 East Middlefield
Road, Mountain View, California 94043; the telephone number is (650) 962-5000.
 
                                        8
<PAGE>   10
 
                              SELLING STOCKHOLDERS
 
     None of the Selling Stockholders is an executive officer or director of
Synopsys, and none of the Selling Stockholders beneficially owns, individually
or in the aggregate, more than 1% of the outstanding Common Stock of Synopsys
prior to this offering. In addition, except as set forth below, all of the
shares of Common Stock beneficially owned by the Selling Stockholders were
issued upon exercise of stock options or direct stock issuances granted under
the Everest Design Automation Inc. 1997 Stock Option/Stock Issuance Plan (the
"Plan"). Beneficial ownership calculations are determined in accordance with the
Rules of the SEC and are based on 68,193,820 shares outstanding as of August 8,
1998 as adjusted to reflect the issuance of 1,392,399 shares of Common Stock in
connection with the acquisition of Everest pursuant to the Merger Agreement (the
"Acquisition"); in computing the number of shares beneficially owned by a person
and the percentage ownership of that person, shares of Common Stock that are
presently exercisable or that will become exercisable within 60 days of November
20, 1998 are deemed outstanding for such person, but are not treated as
outstanding for the purpose of computing the percentage ownership of any other
person. The following table shows the names of the Selling Stockholders and the
number of shares of Common Stock to be sold by them pursuant to this Prospectus.
 
<TABLE>
<CAPTION>
                                                              NUMBER OF SHARES
                          NAME(1)                             BEING OFFERED(2)
                          -------                             ----------------
<S>                                                           <C>
Robi Dutta(3)...............................................      220,590
Pravin Madhani(4)...........................................      220,590
Other Former Shareholders of Everest*.......................      174,713
 
TOTAL.......................................................      615,893
</TABLE>
 
------------
 
* Consists of 16 employees and consultants of Everest who own an aggregate of
  684,320 shares, constituting less than 1% of the outstanding shares of Common
  Stock of Synopsys.
 
(1) Synopsys issued such shares pursuant to the conversion of shares of the
    Common Stock of Everest ("Everest Common Stock") into shares of the Common
    Stock of Synopsys in connection with the Acquisition. Prior to the
    Acquisition, Everest had issued such stock under employee equity incentive
    restricted stock purchase agreements. Unless otherwise noted, each of these
    Selling Stockholders who were parties to the Everest restricted stock
    purchase agreements are currently employees of Synopsys.
 
(2) The number of shares offered pursuant to this offering does not include
    certain shares held in escrow by Synopsys pursuant to the terms of the
    merger agreement in connection with the Acquisition.
 
(3) Mr. Dutta was issued 245,100 shares of Common Stock pursuant to the
    conversion of his shares of Everest Common Stock into shares of Common Stock
    of Synopsys in connection with the Acquisition. Prior to the Acquisition,
    Mr. Dutta was issued shares of Everest Common Stock pursuant to a Founder's
    Restricted Stock Purchase Agreement.
 
(4) Mr. Madhani was issued 245,100 shares of Common Stock pursuant to the
    conversion of his shares of Everest Common Stock into shares of Common Stock
    of Synopsys in connection with the Acquisition. Prior to the Acquisition,
    Mr. Madhani was issued shares of Everest Common Stock pursuant to a
    Founder's Restricted Stock Purchase Agreement.
 
                              PLAN OF DISTRIBUTION
 
     Synopsys has been advised by the Selling Stockholders that they intend to
sell all or a portion of the shares offered hereby from time to time in the
Nasdaq National Market and that sales will be made at prices prevailing in the
Nasdaq National Market at the times of such sales. As used herein, "Selling
Stockholders" includes donees and pledgees selling shares received from a
Selling Stockholder after the date of this Prospectus. The Selling Stockholders
may also make private sales directly or through a broker or brokers, who may act
as agent or as principal. Further, the Selling Stockholders may choose to
dispose of the shares offered hereby by gift to a third party or as a donation
to a charitable or other non-profit entity. In connection with any
 
                                        9
<PAGE>   11
 
sales, the Selling Stockholders and any brokers participating in such sales may
be deemed to be underwriters within the meaning of the Securities Act.
 
     Any broker-dealer participating in such transactions as agent may receive
commissions from the Selling Stockholders (and, if such broker acts as agent for
the purchaser of such shares, from such purchaser). Usual and customary
brokerage fees will be paid by the Selling Stockholders. Broker-dealers may
agree with the Selling Stockholders to sell a specified number of shares at a
stipulated price per share, and, to the extent such a broker-dealer is unable to
do so acting as agent for the Selling Stockholders, to purchase as principal any
unsold shares at the price required to fulfill the broker-dealer commitment to
the Selling Stockholders. Broker-dealers who acquire shares as principal may
thereafter resell such shares from time to time in transactions (which may
involve crosses and block transactions and which may involve sales to and
through other broker-dealers, including transactions of the nature described
above) in the over-the-counter market, in negotiated transactions or otherwise
at market prices prevailing at the time of sale or at negotiated prices, and in
connection with such resales may pay to or receive from the purchasers of such
shares commissions computed as described above.
 
     Synopsys has advised the Selling Stockholders that Regulation M promulgated
under the Exchange Act may apply to sales in the market and has informed them of
the possible need for delivery of copies of this Prospectus. The Selling
Stockholders may indemnify any broker-dealer that participates in transactions
involving the sale of the shares against certain liabilities, including
liabilities arising under the Securities Act. Any commissions paid or any
discounts or concessions allowed to any such broker-dealers, and, if any such
broker-dealers purchase shares as principal, any profits received on the resale
of such shares, may be deemed to be underwriting discounts and commissions under
the Securities Act.
 
     Upon Synopsys's being notified by the Selling Stockholders that any
material arrangement has been entered into with a broker-dealer for the sale of
shares through a cross or block trade, a supplemental prospectus will be filed
under Rule 424(c) under the Securities Act, setting forth the name of the
participating broker-dealer(s), the number of shares involved, the price at
which such shares were sold by the Selling Stockholders, the commissions paid or
discounts or concessions allowed by the Selling Stockholders to such
broker-dealer(s), and where applicable, that such broker-dealer(s) did not
conduct any investigation to verify the information set out in this Prospectus.
 
     Any securities covered by this Prospectus which qualify for sale pursuant
to Rules 144 and 701 under the Securities Act may be sold under Rule 144 rather
than pursuant to this Prospectus. In general, under Rule 144 as currently in
effect, a person (or persons whose shares are aggregated), including any person
who may be deemed to be an "affiliate" of Synopsys, is entitled to sell within
any three month period "restricted shares" beneficially owned by him or her in
an amount that does not exceed the greater of (i) 1% of the then outstanding
shares of Common Stock or (ii) the average weekly trading volume in shares of
Common Stock during the four calendar weeks preceding such sale, provided that
at least one year has elapsed since such shares were acquired from Synopsys or
an affiliate of Synopsys. Sales are also subject to certain requirements as to
the manner of sale, notice and availability of current public information
regarding Synopsys. However, a person who has not been an "affiliate" of
Synopsys at any time within three months prior to the sale is entitled to sell
his or her shares without regard to the volume limitations or other requirements
of Rule 144, provided that at least one year has elapsed since such shares were
acquired from Synopsys or an affiliate of Synopsys. In general, under Rule 701
as currently in effect, any employee, consultant or advisor of Synopsys who
purchases shares from Synopsys in connection with a compensatory stock or option
plan or other written agreement related to compensation is eligible to resell
such shares in reliance on Rule 144, but without compliance with certain
restrictions contained in Rule 144.
 
     There can be no assurance that the Selling Stockholders will sell any or
all of the shares of Common Stock offered hereunder.
 
                                       10
<PAGE>   12
 
                   INDEMNIFICATION OF DIRECTORS AND OFFICERS
 
     Section 145 of the Delaware General Corporation Law permits a corporation
to include in its charter documents, and in agreements between the corporation
and its directors and officers, provisions expanding the scope of
indemnification beyond that specifically provided by the current law.
 
     Article X of Synopsys's Restated Certificate of Incorporation provides for
the indemnification of directors to the fullest extent permissible under
Delaware Law.
 
     Article VII of Synopsys's Bylaws provides for the indemnification of
officers, directors and third parties to the fullest extent permissible under
Delaware Law, which provisions are deemed to be a contract between Synopsys and
each director and officer who serves in such capacity while such bylaw is in
effect.
 
     Synopsys has entered into indemnification agreements with its directors and
executive officers, in addition to the indemnification provided for in the
Registrant's Bylaws, and intends to enter into indemnification agreements with
any new directors and executive officers in the future.
 
     Insofar as indemnification by Synopsys for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of Synopsys pursuant to the provisions referenced in Prospectus or otherwise,
Synopsys has been advised that in the opinion of the Commission such
indemnification is against public policy as expressed in the Securities Act, and
is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by Synopsys of expenses
incurred or paid by a director, officer, or controlling person of Synopsys in
the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered hereunder, Synopsys will, unless in the opinion of its counsel the
matter has been settled by controlling precedent, submit to a court of
appropriate jurisdiction the question whether such indemnification by it is
against public policy as expressed in the Securities Act and will be governed by
the final adjudication of such issue.
 
                                       11
<PAGE>   13
 
                                 SYNOPSYS, INC.
                       REGISTRATION STATEMENT ON FORM S-8
 
                                    PART II
 
                 INFORMATION REQUIRED IN REGISTRATION STATEMENT
 
ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.
 
     There are hereby incorporated by reference in this Registration Statement
the following documents and information heretofore filed with the Commission:
 
     (1) Synopsys's Annual Report on Form 10-K for the fiscal year ended
         September 30, 1997;
 
     (2) Synopsys's Quarterly Report on Form 10-Q for the quarter ended July 4,
         1998;
 
     (3) Synopsys's Quarterly Report on Form 10-Q for the quarter ended April 4,
         1998;
 
     (4) Synopsys's Quarterly Report on Form 10-Q for the quarter ended January
         3, 1998;
 
     (5) Synopsys's Current Report on Form 8-K dated November 16, 1998 relating
         to fourth quarter results;
 
     (6) Synopsys's Current Report on Form 8-K dated December 19, 1997 for the
         acquisition of Viewlogic Systems, Inc.; and
 
     (7) The description of the Synopsys's Common Stock contained in the
         Company's Registration Statement on Form 8-A, No. 000-19807, filed on
         January 24, 1992.
 
     All documents subsequently filed by Synopsys pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Exchange Act, prior to the filing of a post-effective
amendment which indicates that all securities registered have been sold or which
deregisters all securities then remaining unsold, shall be deemed to be
incorporated by reference in this Registration Statement and to be part hereof
from the date of filing of such documents.
 
ITEM 4. DESCRIPTION OF SECURITIES.
 
     Not applicable.
 
ITEM 5. INTERESTS OF NAMED EXPERTS AND COUNSEL.
 
     Not applicable.
 
ITEM 6. INDEMNIFICATION OF DIRECTORS AND OFFICERS.
 
     Section 145 of the Delaware General Corporation Law permits a corporation
to include in its charter documents, and in agreements between the corporation
and its directors and officers, provisions expanding the scope of
indemnification beyond that specifically provided by the current law.
 
     Article X of Synopsys's Restated Certificate of Incorporation provides for
the indemnification of directors to the fullest extent permissible under
Delaware Law.
 
     Article VII of Synopsys's Bylaws provides for the indemnification of
officers, directors and third parties to the fullest extent permissible under
Delaware Law, which provisions are deemed to be a contract between Synopsys and
each director and officer who serves in such capacity while such bylaw is in
effect.
 
     Synopsys has entered into indemnification agreements with its directors and
executive officers, in addition to the indemnification provided for in the
Registrant's Bylaws, and intends to enter into indemnification agreements with
any new directors and executive officers in the future.
 
                                      II-1
<PAGE>   14
 
ITEM 7. EXEMPTION FROM REGISTRATION CLAIMED.
 
     The issuance of the shares being offered by the Form S-3 resale prospectus
were deemed to be exempt from registration under the Securities Act in reliance
on Section 4(2) of the Securities Act or Regulation D promulgated thereunder, or
Rule 701 promulgated under Section 3(b) of the Securities Act, as transactions
by an issuer not involving a public offering or transactions pursuant to
compensatory benefit plans and contracts relating to compensation as provided
under such Rule 701. The recipients of securities in each such transaction
represented their intention to acquire the securities for investment only and
not with a view to or for sale in connection with any distribution thereof and
appropriate legends were affixed to the share certificates and instruments
issued in such transactions. All recipients had adequate access, through their
relationship with Synopsys, to information about Synopsys.
 
ITEM 8. EXHIBITS.
 
<TABLE>
<CAPTION>
EXHIBIT
NUMBER                            DESCRIPTION
-------                           -----------
<C>       <S>
  5.1     Opinion of counsel as to legality of securities being
          registered.
 10.1     Everest Design Automation Inc. 1997 Stock Option/Stock
          Issuance Plan.
 10.2     Form of Stock Option Agreement under Everest Design
          Automation 1997 Stock Option/Stock Issuance Plan.
 10.3     Form of Everest Design Automation Inc. Founder's Restricted
          Stock Agreement.
 10.4     Form of Everest Design Automation Inc. Non-Statutory Option
          Agreement.
 23.1     Consent of counsel (contained in Exhibit 5.1).
 23.2     Independent Auditors' Consent.
 23.3     Independent Accountants' Consent.
 24.1     Power of Attorney (see page II-4).
</TABLE>
 
ITEM 9. UNDERTAKINGS.
 
     A. Synopsys hereby undertakes:
 
          (1) To file, during any period in which offers or sales are being
     made, a post-effective amendment to this registration statement to include
     any material information with respect to the plan of distribution not
     previously disclosed in the Registration Statement or any material change
     to such information in the Registration Statement.
 
          (2) That, for the purpose of determining any liability under the
     Securities Act, each such post-effective amendment shall be deemed to be a
     new registration statement relating to the securities offered therein, and
     the offering of such securities at that time shall be deemed to be the
     initial bona fide offering thereof.
 
          (3) To remove from registration by means of a post-effective amendment
     any of the securities being registered which remain unsold at the
     termination of the offering.
 
     B. Synopsys hereby undertakes that, for purposes of determining any
liability under the Securities Act, each filing of Synopsys's annual report
pursuant to Section 13(a) or Section 15(d) of the Exchange Act (and, where
applicable, each filing of an employee benefit plan's annual report pursuant to
Section 15(d) of the Exchange Act) that is incorporated by reference in the
Registration Statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.
 
                                      II-2
<PAGE>   15
 
     C. Insofar as indemnification for liabilities arising under the Securities
Act may be permitted to directors, officers and controlling persons of Synopsys
pursuant to law, Synopsys's Certificate of Incorporation, Bylaws or
indemnification agreements, Synopsys has been informed that in the opinion of
the Commission such indemnification is against public policy as expressed in the
Securities Act and is therefore unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by Synopsys of
expenses incurred or paid by a director, officer or controlling person of
Synopsys in a successful defense of any action, suit or proceeding) is asserted
by such director, officer or controlling person in connection with the
securities being registered hereunder, Synopsys will, unless in the opinion of
its counsel the matter has already been settled by controlling precedent, submit
to a court of appropriate jurisdiction the question of whether such
indemnification by it is against public policy as expressed in the Securities
Act and will be governed by the final adjudication of such issue.
 
                                      II-3
<PAGE>   16
 
                                   SIGNATURES
 
     Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8/S-3 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Mountain View, State of California, on this 14th day
of December, 1998.
 
                                          SYNOPSYS, INC.
 
                                          By:      /s/ AART J. DE GEUS
                                            ------------------------------------
                                                      Aart J. de Geus
                                                  Chief Executive Officer
 
                               POWER OF ATTORNEY
 
     KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Aart J. de Geus and David Sugishita, and
each of them, as his or her attorney-in-fact, with full power of substitution in
each, for him or her in any and all capacities to sign any amendments to this
Registration Statement on Form S-8/S-3, and to file the same, with exhibits
thereto and other documents in connection therewith, with the Securities and
Exchange Commission, hereby ratifying and confirming all that said
attorney-in-fact, or his substitutes, may do or cause to be done by virtue
hereof.
 
     Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed below by the following persons in the
capacities and on the dates indicated.
 
<TABLE>
<CAPTION>
                       SIGNATURE                                    TITLE                   DATE
                       ---------                                    -----                   ----
<S>                                                       <C>                         <C>
/s/ AART J. DE GEUS                                       Chief Executive Officer     December 14 1998
--------------------------------------------------------  (Principal Executive
Aart J. de Geus                                           Officer) and Chairman of
                                                          the Board of Directors
 
/s/ CHI-FOON CHAN                                         President, Chief Operating  December 14, 1998
--------------------------------------------------------  Officer and Director
Chi-Foon Chan
 
/s/ WILLIAM W. LATTIN                                     Executive Vice President    December 14, 1998
--------------------------------------------------------  and Director
William W. Lattin
 
/s/ DEBORAH COLEMAN                                       Director                    December 14, 1998
--------------------------------------------------------
Deborah Coleman
 
/s/ HARVEY C. JONES, JR.                                  Director                    December 14, 1998
--------------------------------------------------------
Harvey C. Jones, Jr.
 
/s/ A. RICHARD NEWTON                                     Director                    December 14, 1998
--------------------------------------------------------
A. Richard Newton
 
/s/ STEVEN C. WALSKE                                      Director                    December 14, 1998
--------------------------------------------------------
Steven C. Walske
 
/s/ DAVID SUGISHITA                                       Chief Financial Officer     December 14, 1998
--------------------------------------------------------  (Principal Financial
David Sugishita                                           Officer)
</TABLE>
 
                                      II-4
<PAGE>   17
 
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
 
                            ------------------------
 
                                    EXHIBITS
                            ------------------------
 
                     REGISTRATION STATEMENT ON FORM S-8/S-3
 
                                 SYNOPSYS, INC.
 
                               DECEMBER 14, 1998
 
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
<PAGE>   18
 
                               INDEX TO EXHIBITS
 
<TABLE>
<CAPTION>
EXHIBIT                                                                SEQUENTIALLY
NUMBER                           DESCRIPTION                           NUMBERED PAGE
-------                          -----------                           -------------
<C>      <S>                                                           <C>
    5.1  Opinion of counsel as to legality of securities being
         registered.
   10.1  Everest Design Automation Inc. 1997 Stock Option/Stock
         Issuance Plan.
   10.2  Form of Stock Option Agreement under Everest Design
         Automation 1997 Stock Option/Stock Issuance Plan.
   10.3  Form of Everest Design Automation Inc. Founder's Restricted
         Stock Agreement.
   10.4  Form of Everest Design Automation Inc. Non-Statutory Stock
         Option Agreement.
   23.1  Consent of counsel (contained in Exhibit 5.1).
   23.2  Independent Auditors' Consent.
   23.3  Independent Accountants' Consent.
   24.1  Power of Attorney (see page II-4).
</TABLE>
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 59010}]
{"company-data": {"conformed-name": "SYNOPSYS INC", "cik": "0000883241", "assigned-sic": "7372", "irs-number": "561546236", "state-of-incorporation": "DE", "fiscal-year-end": "0930"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-68883", "film-number": "98769175"}, "business-address": {"street1": "700 E MIDDLEFIELD RD", "city": "MOUNTAIN VIEW", "state": "CA", "zip": "94043-4033", "phone": "4159625000"}, "mail-address": {"street1": "700 E MIDDLEFIELD RD", "city": "MOUNTAIN VIEW", "state": "CA", "zip": "94043-4033"}}
1
 
   AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON DECEMBER 14, 1998
 
                                                     REGISTRATION NO.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                            ------------------------
 
                                  FORM S-8/S-3
                             REGISTRATION STATEMENT
(INCLUDING REGISTRATION OF SHARES FOR RESALE BY MEANS OF A FORM S-3 PROSPECTUS)
                                     UNDER
                           THE SECURITIES ACT OF 1933
 
                                 SYNOPSYS, INC.
               (EXACT NAME OF REGISTRANT AS SPECIFIED IN CHARTER)
DELAWARE                                           56-1546236
             (STATE OF INCORPORATION)                      (I.R.S. EMPLOYER IDENTIFICATION NO.)
700 E. MIDDLEFIELD ROAD
                            MOUNTAIN VIEW, CA 94043
                    (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)
 
      EVEREST DESIGN AUTOMATION INC. 1997 STOCK OPTION/STOCK ISSUANCE PLAN
                 FOUNDER'S RESTRICTED STOCK PURCHASE AGREEMENTS
           EVEREST DESIGN AUTOMATION INC. NON-STATUTORY STOCK OPTIONS
                            (FULL TITLE OF THE PLAN)
 
                                AART J. DE GEUS
                     PRESIDENT AND CHIEF EXECUTIVE OFFICER
                                 SYNOPSYS, INC.
                            700 E. MIDDLEFIELD ROAD
                            MOUNTAIN VIEW, CA 94043
                                 (650) 962-5000
(NAME, ADDRESS, AND TELEPHONE NUMBER, INCLUDING AREA CODE, OF AGENT FOR SERVICE)
 
                                    COPY TO:
                           THOMAS C. DEFILIPPS, ESQ.
                        WILSON SONSINI GOODRICH & ROSATI
                            PROFESSIONAL CORPORATION
                               650 PAGE MILL ROAD
                            PALO ALTO, CA 94304-1050
                                 (415) 493-9300
 
                        CALCULATION OF REGISTRATION FEE
--------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------
                                                   MAXIMUM         PROPOSED MAXIMUM     PROPOSED MAXIMUM
TITLE OF SECURITIES                              AMOUNT TO BE       OFFERING PRICE     AGGREGATE OFFERING        AMOUNT OF
TO BE REGISTERED                                REGISTERED(1)          PER SHARE             PRICE            REGISTRATION FEE
--------------------------------------------------------------------------------------------------------------------------------
Common Stock, $0.01 par value
  Issued under Restricted Stock Purchase
    Agree-
    ments of Everest Design Automation
    Inc. ..................................   441,180 shares(3)       $52.6875(2)        $23,244,671.25          $6,462.02
  Issued under the Everest Design
    Automation Inc. 1997 Stock Option/Stock
    Issuance Plan..........................   152,654 shares(3)       $52.6875(2)        $ 8,042,957.63          $2,235.94
  Issued under Everest Design Automation
    Inc. Non-Statutory Stock Options.......     22,059 shares         $52.6875(2)        $ 1,162,233.56          $  323.10
  To be issued under the Everest Design
    Automation Inc. 1997 Stock Option/Stock
    Issuance Plan..........................   111,357 shares(3)       $ 4.3200(4)        $  481,062.24           $  133.74
--------------------------------------------------------------------------------------------------------------------------------
         Total.............................     727,250 shares                           $32,930,924.68          $9,154.80
--------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------
(1) For the sole purpose of calculating the registration fee, the number of
    shares to be registered under this Registration Statement has been broken
    down into four subtotals.
 
(2) Computed in accordance with Rule 457(h) under the Securities Act. Such
    computation is based on the average of the high and low prices reported on
    the Nasdaq National Market on December 10, 1998.
 
(3) Certain of such shares are subject to vesting.
 
(4) Computed in accordance with Rules 457(h) and 457(i) under the Securities
    Act. Such computation is based on the weighted average exercise price of
    $0.29 per share covering authorized but unissued shares under Everest Design
    Automation Inc.'s 1997 Stock Option/Stock Issuance Plan.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
2
 
PROSPECTUS
 
Synopsys, Inc.
700 East Middlefield Road
Mountain View, CA 94043
Telephone Number: (650) 962-5000
 
                                 727,250 SHARES
 
                                      LOGO
 
                                  COMMON STOCK
 
                            ------------------------
 
     These shares may be offered and sold from time to time by certain
stockholders of the Company identified in this prospectus. See "Selling
Stockholders." The selling stockholders acquired the shares on November 20, 1998
in connection with the acquisition by Synopsys, Inc. ("Synopsys") of Everest
Design Automation Inc. ("Everest") pursuant to an Agreement of Merger and Plan
of Reorganization by and among Synopsys, Tenzing Acquisition Corporation, a
Delaware corporation and a wholly-owned subsidiary of Synopsys, and Everest,
dated as of October 26, 1998 (the "Merger Agreement").
 
     The selling stockholders will receive all of the net proceeds from the sale
of the shares. These stockholders will pay all underwriting discounts and
selling commissions, if any, applicable to the sale of the shares. Synopsys will
not receive any proceeds from the sale of the shares.
 
     YOU SHOULD CONSIDER CAREFULLY THE RISK FACTORS BEGINNING ON PAGE 3 OF THIS
PROSPECTUS BEFORE PURCHASING ANY OF THE COMMON STOCK.
 
     Synopsys' common stock is quoted on the Nasdaq National Market under the
symbol "SNPS." On December 10, 1998, the last reported sale of the common stock
was $51.625 per share.
 
                            ------------------------
 
     The Securities and Exchange Commission and state securities regulators have
not approved or disapproved these securities, or determined if this prospectus
is truthful or complete. Any representation to the contrary is a criminal
offense.
 
                            ------------------------
 
                               December 14, 1998
3
 
                               TABLE OF CONTENTS
 
                                   PROSPECTUS
PAGE
                                                              ----
Synopsys, Inc...............................................    3
Risk Factors................................................    3
Where to Find More Information About Synopsys...............    7
Information Incorporated by Reference.......................    7
Selling Stockholders........................................    9
Plan of Distribution........................................   10
Indemnification of Directors and Officers...................   12
You should rely only on the information contained in this prospectus. We
have not authorized anyone to provide you with information different from that
contained in this prospectus. The selling stockholders are offering to sell, and
seeking offers to buy, shares of Synopsys common stock only in jurisdictions
where offers and sales are permitted. The information contained in this
prospectus is accurate as of the date of this prospectus, regardless of the time
of delivery of this prospectus or any sale of the shares.
 
     In this prospectus, unless indicated otherwise, "Synopsys," the "Company,"
"we," "us" and "our" refer to Synopsys, Inc. and its subsidiaries.
 
                          FORWARD LOOKING INFORMATION
 
     This prospectus, including the information incorporated by reference
herein, contains forward-looking statements within the meaning of Section 27A of
the Securities Act of 1933, as amended (the "Securities Act") and Section 21E of
the Exchange Act of 1934 (the "Exchange Act"). Our actual results could differ
materially from those projected in the forward-looking statements as a result of
the risk factors set forth below. In addition, please review the sections
captioned "Management's Discussion and Analysis of Financial Condition and
Results of Operations" in our annual report on Form 10-K for the fiscal year
ended September 30, 1997, and our quarterly reports on form 10-Q for the
quarters ended July 4, 1998, April 4, 1998 and January 3, 1998, which reports
are incorporated herein by reference and such section of any subsequently filed
Exchange Act reports. In connection with forward-looking statements which appear
in these disclosures, prospective purchasers of the shares offered hereby should
carefully consider the factors set forth in this prospectus under "Risk
Factors."
 
                                        2
4
 
                                 SYNOPSYS, INC.
 
     Synopsys develops, markets, and supports electronic design automation
("EDA") products for designers of integrated circuits ("ICs") and electronic
systems. Synopsys offers a range of design tools, verification tools and
systems, design reuse products and physical design tools intended to improve
designers' productivity by offering improved time to market, reduced development
and manufacturing costs, and enhanced design quality of results when compared to
earlier generations of EDA products. Synopsys also provides training, support
and consulting services for its customers.
 
                                  RISK FACTORS
 
     You should carefully consider the risks described below before making an
investment decision. The risks and uncertainties described below are not the
only ones facing our company. The risk factors set forth herein reflect those
risks known to management as of the date of this prospectus and which management
believes could be material to our business, operating results and financial
condition. Additional risks and uncertainties not presently known to us or that
we currently deem immaterial may also impair our business operations. Such risk
factors may change over time and may differ materially from those set forth
herein. Prospective investors are cautioned to review, in addition to these risk
factors, the risk factors contained in "Management's Discussion and Analysis of
Financial Condition and Results of Operations" contained in our most recent
Annual Report on Form 10-K or Quarterly Report on Form 10-Q as well as the
additional information contained in such reports and our other reports and
filings with the Securities and Exchange Commission.
 
     If any of the following risks actually occur, our business, financial
condition or results of operations could be materially adversely affected. In
such case, the trading price of our common stock could decline and you may lose
all or part of your investment.
 
     This prospectus contains forward-looking statements that involve risks and
uncertainties. Our actual results could differ materially from those anticipated
in such forward-looking statement as a result of a variety of factors, including
those set forth in the following risk factors or elsewhere in, or incorporated
by reference into, this prospectus.
 
POTENTIAL EARNINGS FLUCTUATIONS
 
     We attempt to plan our business to achieve quarter-to-quarter revenue and
earnings growth. Achieving predictable revenue and earnings growth is difficult.
Quarterly revenue and earnings are affected by many factors, including customer
product demand, product license terms, the size of our backlog, and the timing
of revenue recognition on products and services sold. The following factors
could affect our revenues and earnings per share in a particular quarter or over
several quarterly or annual periods:
 
     - Our orders are seasonal. Historically, our first fiscal quarter ending
       December 31 is our weakest, and may have a book-to-bill ratio below one.
 
     - Our products are complex, and before buying them potential customers
       spend a great deal of time reviewing and testing them. This is
       particularly true if they are new customers or current customers
       purchasing a new product or switching from a competitor's product. The
       sales cycle does not necessarily match quarterly periods, and if by the
       end of any quarter our sales force has not sold enough new licenses, our
       orders and revenues could be substantially reduced.
 
     - Like many companies in the software industry, we receive a
       disproportionate volume of orders in the last week of a quarter, and
       recognize a disproportionate amount of revenue in the last week of a
       quarter. In addition, the proportion of our business attributable to our
       largest customers is increasing. As a result, if any order, and
       especially a large order, is delayed beyond the end of a fiscal period,
       our orders and revenue for that period could be substantially reduced.
 
                                        3
5
 
     - The accounting rules we are required to follow only permit us to
       recognize revenue when certain criteria are met. Orders for certain of
       the Company's products and services, including certain time-based product
       licenses, consulting services, and software support, yield revenue (or a
       significant portion thereof) over multiple quarters (often extending
       beyond the current fiscal year) or upon completion of performance rather
       than at the time of sale. In addition, in negotiating a purchase order
       with a customer, we may agree to terms that have the effect of requiring
       deferral of revenue in whole or in part. As a result, it may be difficult
       for us to convert orders, particularly those received late in a quarter,
       or backlog, to revenue in any given quarter. It is therefore possible for
       the Company to fall short in its revenue and/or earnings plan for a given
       quarter even while orders and backlog remain on plan.
 
COMPETITION
 
     The EDA industry is highly competitive. We compete against other EDA
vendors, and with customers' internally developed design tools and internal
design capabilities, for a share of the overall EDA budgets of our customers.
Our competitors include companies that offer a broad range of products and
services, such as Cadence Design Systems, Inc. ("Cadence"), Mentor Graphics,
Inc. ("Mentor") and Avant! Corporation ("Avant!"), as well as companies,
including numerous start-up companies, that offer products focused on a discrete
phase of the IC design process. In order to remain successful against such
competition, we must continue to enhance our current products and bring to
market new products that address the increasingly sophisticated needs of our
customers on a timely and cost-effective basis. We also will have to expand our
ability to offer consulting services. The failure to enhance existing products,
develop and/or acquire new products or to expand our ability to offer such
services would have a material adverse effect on our business, financial
condition and results of operations.
 
     Technology advances and customer requirements are fueling a change in the
nature of competition among EDA vendors. Increasingly, EDA companies compete on
the basis of "design flows" involving a broad range of products (including both
logic and physical design tools) and services rather than on the basis of
individual "point" tools performing a discrete phase of the design process. No
single EDA company currently offers its customers industry-leading products in a
complete design flow. We offer a wide range of logic design tools but currently
offer a relatively limited range of physical design tools. In November 1998 we
acquired Everest, a private company developing physical design software. We will
need to develop or acquire additional physical design tools in order to offer a
complete design flow. We are also attempting to expand our capacity to offer
professional services, but for the foreseeable future will continue to have less
capacity than Cadence to provide such services. The market for physical design
tools is dominated by Cadence and Avant!, both of which are attempting to
complete their design flows. Cadence recently acquired Ambit Design Systems, a
private company offering synthesis and other logic design products, as well as
certain physical design verification products from Lucent Technologies, both of
which will increase the direct competition between Synopsys and Cadence. In
addition, Cadence's acquisition of logic design products may lead to reductions
in purchases of our logic design software by Cadence, which was one of Synopsys'
ten largest customers in fiscal 1998. Avant! also recently acquired a private
company offering logic synthesis software, which will increase the direct
competition between Synopsys and Avant!.
 
SUCCESS OF NON-SYNTHESIS PRODUCTS
 
     Historically, much of the Company's growth has been attributable to the
strength of its logic synthesis products. Opportunities for growth in market
share in this area are limited, and synthesis revenues are expected to grow more
slowly than our target for overall revenue growth. Synthesis and related "design
creation" products account for approximately 45-50% of our revenue. As a result,
in order to meet our revenue plan, non-synthesis design creation products, high
level verification products and deep submicron products and our services
business will have to grow faster than our overall revenue growth target.
 
     Our PrimeTime timing analysis, Formality formal verification, Module
Compiler datapath synthesis and VCS Verilog simulation products are expected to
be among the most important contributors to product revenue growth. These
products have achieved initial customer acceptance, but we will only derive
significant revenue from these products if they are accepted by a broad range of
customers. Product success is difficult to
                                        4
6
 
predict. The introduction of new products and growth of a market for such
products cannot be assured in a highly competitive environment like EDA. In the
past we, like all companies, have had products that despite initial successes,
have failed to meet our revenue expectations. Expanding our capacity to offer
consulting services and our revenues derived therefrom will require us to
recruit, hire and train a large number of talented people, and to implement
management controls on bidding and executing on services engagements. The
consulting business is significantly different than the software business,
however, and as indicated by recent layoffs announced by Cadence in its service
business, increasing consulting orders and revenue while maintaining an adequate
level of profit can be difficult. There can be no assurance that the Company
will be successful in expanding revenues from existing or new products at the
desired rate or expanding its services business, and the failure to do so would
have a material adverse effect on the Company's business, financial condition
and results of operations.
 
INTEGRATION OF ACQUIRED BUSINESSES
 
     We have acquired or merged with a number of companies in recent years,
including EPIC Design Technology, Inc., Viewlogic Systems, Inc., Systems Science
Inc. and Everest, and as part of our efforts to expand our product and services
offerings we may acquire additional companies in the future. In addition to
direct costs, acquisitions pose a number of risks, including potential dilution
of earnings per share, problems of integrating the acquired products and
employees into our business, the failure to realize expected synergies or cost
savings, the drain on management time for acquisition-related activities,
possible adverse effects on customer buying patterns due to uncertainties
resulting from an acquisition, and assumption of unknown liabilities. While we
attempt to review proposed acquisitions carefully and negotiate terms that are
favorable to the Company, there is no assurance that any individual acquisition
will have the projected effect on the Company's performance.
 
DEPENDENCE ON SEMICONDUCTOR AND ELECTRONICS BUSINESSES
 
     Our business has benefited from the rapid worldwide growth of the
semiconductor industry. Purchases of our products are largely dependent upon the
commencement of new design projects by semiconductor manufacturers and their
customers. The outlook for the semiconductor industry for the remainder of
calendar year 1998 and 1999 is uncertain, owing in part to adverse economic
conditions in Asia and to potential slowing of growth in the United States. A
number of the Company's customers have announced layoffs of their employees or
the suspension of investment plans, and although the Company has not seen a
significant drop-off in demand from these customers, their EDA budgets could be
reduced, alone or as part of overall expense control efforts. In addition, there
have been a number of mergers in the semiconductor and systems industries, which
may reduce the aggregate level of purchases of our products and services by the
merged companies. Slower growth in the semiconductor and systems industries, a
reduced number of design starts, tightening of customers' operating budgets or
continued consolidation among the Company's customers may have a material
adverse effect on our business, financial condition and results of operations.
 
INTERNATIONAL EXPOSURE
 
     In fiscal 1998, international revenue accounted for 39% of our revenue,
after accounting for 41% and 42% of our revenue in fiscal 1997 and 1996,
respectively. We expect that international revenue will continue to account for
a significant portion of our revenue in the future. As a result, the Company's
performance may be negatively affected by changes in foreign currency exchange
rates and changes in regional or worldwide economic or political conditions. In
particular:
 
     - Revenue from sales in Japan during fiscal 1998 was adversely affected by
       the weakness of the yen against the dollar, overall weakness in the
       Japanese economy and the deferral of investments in semiconductor
       facilities and technology by Japanese companies. Continued weakness of
       the Japanese economy during fiscal 1999 is likely to adversely affect
       revenue from Japan during the year. The yen has recently strengthened,
       but the exchange rate for fiscal 1999 remains subject to unpredictable
       fluctuations. Renewed weakness of the yen could adversely affect revenue
       from Japan during fiscal 1999.
                                        5
7
 
     - Significant declines in the value of the Korean won during fiscal 1998,
       and the subsequent economic crisis had a significant adverse affect on
       our business in Korea during the year, and is likely to continue to
       affect our orders and revenue from Korea in fiscal 1999. Declines in the
       currencies of other countries in the Asia Pacific region, particularly
       Taiwan, have also negatively affected the Company's sales in the region.
       Continued instability in Asian currency markets and weaknesses in Asian
       economies would continue to have an adverse effect on our orders and
       revenues from the Asia Pacific region.
 
RISKS OF JOINT DEVELOPMENT
 
     In February 1996, we entered into a six-year joint development and license
agreement with IBM, pursuant to which the two companies agreed to develop
certain new products. Joint development of products is subject to risks and
uncertainties over and above those affecting internal development. During fiscal
year 1997, the first joint product resulting from the alliance, PrimeTime, was
introduced, and the parties agreed to terminate efforts to develop a product in
one of the product areas covered by the Agreement. A second joint product is
expected to be introduced in January 1999, and development of the fourth product
to be developed under the agreement has been suspended. Synopsys and IBM are
currently discussing the future of the alliance. There can be no assurance that
joint development will continue, or that the products developed by the alliance
will be successful.
 
NEED TO RECRUIT AND RETAIN KEY PERSONNEL
 
     Our success is dependent on technical and other contributions of key
employees. We participate in a dynamic industry, with significant start-up
activity, and our headquarters is in Silicon Valley, where skilled technical,
sales and management employees are in high demand. There is a limited number of
qualified EDA engineers, and the competition for such individuals is intense.
Experience at Synopsys is highly valued in the EDA industry, and our employees
are recruited aggressively by our competitors and by start-up companies. Our
salaries are competitive in the market, but under certain circumstances,
start-up companies can offer more attractive stock option packages. As a result,
we have experienced, and may continue to experience, significant employee
turnover. In addition, there can be no assurance that we can continue to recruit
and retain key personnel. Failure to successfully recruit and retain such
personnel could have a material adverse effect on our business, financial
condition and results of operations.
 
POISON PILL PROVISIONS
 
     The Company has adopted a number of provisions that could have
anti-takeover effects. The Board of Directors has adopted a Preferred Shares
Rights Plan, commonly referred to as a "poison pill." In addition, the Board of
Directors has the authority, without further action by its stockholders, to fix
the rights and preferences of, and issue shares of, authorized but undesignated
shares of Preferred Stock. This provision and other provisions of the Company's
Restated Certificate of Incorporation and Bylaws and the Delaware General
Corporation Law may have the effect of deterring hostile takeovers or delaying
or preventing changes in control or management of the Company, including
transactions in which the stockholders of the Company might otherwise receive a
premium for their shares over then current market prices.
 
YEAR 2000
 
     Synopsys presently believes that we will not experience significant
operational problems arising from the Year 2000 problem (i.e., the inability of
certain computer programs to correctly process date information on or after
January 1, 2000). However, if unforeseen Year 2000 issues arise with respect to
Synopsys products, one or more important customers experiences Year 2000-related
problems that interferes with their purchases of Synopsys products, or we are
not able to identify and fix Year 2000 problems relating to the computer systems
and software we rely on to run our business, we may experience a disruption in
our business, which could have a material adverse impact on our business,
financial condition and results of operations.
 
                                        6
8
 
CHANGES IN FINANCIAL ACCOUNTING STANDARDS
 
     We prepare our financial statements in conformity with generally accepted
accounting principles ("GAAP"). GAAP are subject to interpretation by the
American Institute of Certified Public Accountants ("AICPA"), the Securities and
Exchange Commission (the "SEC") and various bodies formed to interpret and
create appropriate accounting policies. A change in these policies can have a
significant effect on our reported results, and may even affect our reporting of
transactions completed before a change is announced. Accounting policies
affecting many other aspects of our business, including rules relating to
software revenue recognition, purchase and pooling-of-interests accounting for
business combinations, employee stock purchase plans and stock option grants
have recently been revised or are under review by one or more groups. Changes to
these rules, or the questioning of current practices, may have a significant
adverse affect on our reported financial results or in the way we conduct our
business.
 
     In addition, the preparation of financial statements in conformity with
GAAP requires us to make estimates and assumptions that affect the recorded
amounts of assets and liabilities, disclosure of those assets and liabilities at
the date of the financial statements and the recorded amounts of expenses during
the reporting period. A change in the facts and circumstances surrounding these
estimates could result in a change to the estimates and impact future operating
results.
 
                 WHERE TO FIND MORE INFORMATION ABOUT SYNOPSYS
 
     We file special reports, proxy statements and other information with the
SEC. You may read and copy any document we file at the SEC's public reference
rooms in Washington, D.C., New York, New York and Chicago, Illinois. Please call
the SEC at 1-800-SEC-0330 for further information on the public reference rooms.
Our SEC filings are also available to the public from the SEC's Web site at
http://www.sec.gov.
 
     This prospectus contains information concerning the Company and the sale of
its Common Stock by the Selling Stockholders, but does not contain all the
information set forth in the Registration Statement on Form S-8/S-3 (the
"Registration Statement") which the Company has filed with the SEC under the
Securities Act of 1933, as amended (the "Securities Act"). Statements made in
this Prospectus as to the contents of any referenced contract, agreement or
other document are not necessarily complete, and such statement shall be deemed
qualified in its entirety by reference thereto. The Registration Statement,
including various exhibits, may be obtained upon payment of the fee prescribed
by the SEC, or may be examined without charge at the SEC's office in Washington,
D.C.
 
                     INFORMATION INCORPORATED BY REFERENCE
 
     The SEC allows us to "incorporate by reference" the information we file
with them, which means that we can disclose important information to you by
referring you to those documents that we have previously filed with the SEC or
documents that we will file with the SEC in the future. The information
incorporated by reference is considered to be part of this prospectus, and later
information that we file with the SEC will automatically update and supercede
this information. We incorporate by reference the documents listed below, and
any future filings made with the SEC under Sections 13(a), 13(c), 14 or 15(d) of
the Exchange Act, until the selling stockholders sell all the shares. This
prospectus is part of a Registration Statement we filed with the SEC. The
documents we incorporate by reference are:
 
     (1) Synopsys's Annual Report on Form 10-K for the fiscal year ended
         September 30, 1997;
 
     (2) Synopsys's Quarterly Report on Form 10-Q for the quarter ended July 4,
         1998;
 
     (3) Synopsys's Quarterly Report on Form 10-Q for the quarter ended April 4,
         1998;
 
     (4) Synopsys's Quarterly Report on Form 10-Q for the quarter ended January
         3, 1998;
 
     (5) Synopsys's Current Report on Form 8-K dated November 16, 1998 relating
         to fourth quarter results;
 
                                        7
9
 
     (6) Synopsys's Current Report on Form 8-K dated December 19, 1997 for the
         acquisition of Viewlogic Systems, Inc.; and
 
     (7) The description of the Synopsys's Common Stock contained in the
         Company's Registration Statement on Form 8-A, No. 000-19807, filed on
         January 24, 1992.
 
     We also incorporate by reference all documents subsequently filed by the
Company pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act,
prior to the filing of a post-effective amendment which indicates that all
securities registered have been sold or which deregisters all securities then
remaining unsold.
 
     Any statement contained in a document incorporated or deemed to be
incorporated by reference herein shall be deemed to be modified or superseded
for purposes of the Registration Statement or this Prospectus to the extent that
a statement contained herein, in a Prospectus Supplement or in any other
document subsequently filed with the Commission which also is or is deemed to be
incorporated by reference herein modifies or supersedes such statement. Any such
statement so modified or superseded shall not be deemed, except as so modified
or superseded, to constitute a part of the Registration Statement or this
Prospectus.
 
     You may request a copy of these filings, at no cost, by writing or
telephoning us at the following address: Synopsys, Inc., 700 East Middlefield
Road, Mountain View, California 94043; the telephone number is (650) 962-5000.
 
                                        8
10
 
                              SELLING STOCKHOLDERS
 
     None of the Selling Stockholders is an executive officer or director of
Synopsys, and none of the Selling Stockholders beneficially owns, individually
or in the aggregate, more than 1% of the outstanding Common Stock of Synopsys
prior to this offering. In addition, except as set forth below, all of the
shares of Common Stock beneficially owned by the Selling Stockholders were
issued upon exercise of stock options or direct stock issuances granted under
the Everest Design Automation Inc. 1997 Stock Option/Stock Issuance Plan (the
"Plan"). Beneficial ownership calculations are determined in accordance with the
Rules of the SEC and are based on 68,193,820 shares outstanding as of August 8,
1998 as adjusted to reflect the issuance of 1,392,399 shares of Common Stock in
connection with the acquisition of Everest pursuant to the Merger Agreement (the
"Acquisition"); in computing the number of shares beneficially owned by a person
and the percentage ownership of that person, shares of Common Stock that are
presently exercisable or that will become exercisable within 60 days of November
20, 1998 are deemed outstanding for such person, but are not treated as
outstanding for the purpose of computing the percentage ownership of any other
person. The following table shows the names of the Selling Stockholders and the
number of shares of Common Stock to be sold by them pursuant to this Prospectus.
NUMBER OF SHARES
                          NAME(1)                             BEING OFFERED(2)
                          -------                             ----------------
Robi Dutta(3)...............................................      220,590
Pravin Madhani(4)...........................................      220,590
Other Former Shareholders of Everest*.......................      174,713
 
TOTAL.......................................................      615,893
------------
 
* Consists of 16 employees and consultants of Everest who own an aggregate of
  684,320 shares, constituting less than 1% of the outstanding shares of Common
  Stock of Synopsys.
 
(1) Synopsys issued such shares pursuant to the conversion of shares of the
    Common Stock of Everest ("Everest Common Stock") into shares of the Common
    Stock of Synopsys in connection with the Acquisition. Prior to the
    Acquisition, Everest had issued such stock under employee equity incentive
    restricted stock purchase agreements. Unless otherwise noted, each of these
    Selling Stockholders who were parties to the Everest restricted stock
    purchase agreements are currently employees of Synopsys.
 
(2) The number of shares offered pursuant to this offering does not include
    certain shares held in escrow by Synopsys pursuant to the terms of the
    merger agreement in connection with the Acquisition.
 
(3) Mr. Dutta was issued 245,100 shares of Common Stock pursuant to the
    conversion of his shares of Everest Common Stock into shares of Common Stock
    of Synopsys in connection with the Acquisition. Prior to the Acquisition,
    Mr. Dutta was issued shares of Everest Common Stock pursuant to a Founder's
    Restricted Stock Purchase Agreement.
 
(4) Mr. Madhani was issued 245,100 shares of Common Stock pursuant to the
    conversion of his shares of Everest Common Stock into shares of Common Stock
    of Synopsys in connection with the Acquisition. Prior to the Acquisition,
    Mr. Madhani was issued shares of Everest Common Stock pursuant to a
    Founder's Restricted Stock Purchase Agreement.
 
                              PLAN OF DISTRIBUTION
 
     Synopsys has been advised by the Selling Stockholders that they intend to
sell all or a portion of the shares offered hereby from time to time in the
Nasdaq National Market and that sales will be made at prices prevailing in the
Nasdaq National Market at the times of such sales. As used herein, "Selling
Stockholders" includes donees and pledgees selling shares received from a
Selling Stockholder after the date of this Prospectus. The Selling Stockholders
may also make private sales directly or through a broker or brokers, who may act
as agent or as principal. Further, the Selling Stockholders may choose to
dispose of the shares offered hereby by gift to a third party or as a donation
to a charitable or other non-profit entity. In connection with any
 
                                        9
11
 
sales, the Selling Stockholders and any brokers participating in such sales may
be deemed to be underwriters within the meaning of the Securities Act.
 
     Any broker-dealer participating in such transactions as agent may receive
commissions from the Selling Stockholders (and, if such broker acts as agent for
the purchaser of such shares, from such purchaser). Usual and customary
brokerage fees will be paid by the Selling Stockholders. Broker-dealers may
agree with the Selling Stockholders to sell a specified number of shares at a
stipulated price per share, and, to the extent such a broker-dealer is unable to
do so acting as agent for the Selling Stockholders, to purchase as principal any
unsold shares at the price required to fulfill the broker-dealer commitment to
the Selling Stockholders. Broker-dealers who acquire shares as principal may
thereafter resell such shares from time to time in transactions (which may
involve crosses and block transactions and which may involve sales to and
through other broker-dealers, including transactions of the nature described
above) in the over-the-counter market, in negotiated transactions or otherwise
at market prices prevailing at the time of sale or at negotiated prices, and in
connection with such resales may pay to or receive from the purchasers of such
shares commissions computed as described above.
 
     Synopsys has advised the Selling Stockholders that Regulation M promulgated
under the Exchange Act may apply to sales in the market and has informed them of
the possible need for delivery of copies of this Prospectus. The Selling
Stockholders may indemnify any broker-dealer that participates in transactions
involving the sale of the shares against certain liabilities, including
liabilities arising under the Securities Act. Any commissions paid or any
discounts or concessions allowed to any such broker-dealers, and, if any such
broker-dealers purchase shares as principal, any profits received on the resale
of such shares, may be deemed to be underwriting discounts and commissions under
the Securities Act.
 
     Upon Synopsys's being notified by the Selling Stockholders that any
material arrangement has been entered into with a broker-dealer for the sale of
shares through a cross or block trade, a supplemental prospectus will be filed
under Rule 424(c) under the Securities Act, setting forth the name of the
participating broker-dealer(s), the number of shares involved, the price at
which such shares were sold by the Selling Stockholders, the commissions paid or
discounts or concessions allowed by the Selling Stockholders to such
broker-dealer(s), and where applicable, that such broker-dealer(s) did not
conduct any investigation to verify the information set out in this Prospectus.
 
     Any securities covered by this Prospectus which qualify for sale pursuant
to Rules 144 and 701 under the Securities Act may be sold under Rule 144 rather
than pursuant to this Prospectus. In general, under Rule 144 as currently in
effect, a person (or persons whose shares are aggregated), including any person
who may be deemed to be an "affiliate" of Synopsys, is entitled to sell within
any three month period "restricted shares" beneficially owned by him or her in
an amount that does not exceed the greater of (i) 1% of the then outstanding
shares of Common Stock or (ii) the average weekly trading volume in shares of
Common Stock during the four calendar weeks preceding such sale, provided that
at least one year has elapsed since such shares were acquired from Synopsys or
an affiliate of Synopsys. Sales are also subject to certain requirements as to
the manner of sale, notice and availability of current public information
regarding Synopsys. However, a person who has not been an "affiliate" of
Synopsys at any time within three months prior to the sale is entitled to sell
his or her shares without regard to the volume limitations or other requirements
of Rule 144, provided that at least one year has elapsed since such shares were
acquired from Synopsys or an affiliate of Synopsys. In general, under Rule 701
as currently in effect, any employee, consultant or advisor of Synopsys who
purchases shares from Synopsys in connection with a compensatory stock or option
plan or other written agreement related to compensation is eligible to resell
such shares in reliance on Rule 144, but without compliance with certain
restrictions contained in Rule 144.
 
     There can be no assurance that the Selling Stockholders will sell any or
all of the shares of Common Stock offered hereunder.
 
                                       10
12
 
                   INDEMNIFICATION OF DIRECTORS AND OFFICERS
 
     Section 145 of the Delaware General Corporation Law permits a corporation
to include in its charter documents, and in agreements between the corporation
and its directors and officers, provisions expanding the scope of
indemnification beyond that specifically provided by the current law.
 
     Article X of Synopsys's Restated Certificate of Incorporation provides for
the indemnification of directors to the fullest extent permissible under
Delaware Law.
 
     Article VII of Synopsys's Bylaws provides for the indemnification of
officers, directors and third parties to the fullest extent permissible under
Delaware Law, which provisions are deemed to be a contract between Synopsys and
each director and officer who serves in such capacity while such bylaw is in
effect.
 
     Synopsys has entered into indemnification agreements with its directors and
executive officers, in addition to the indemnification provided for in the
Registrant's Bylaws, and intends to enter into indemnification agreements with
any new directors and executive officers in the future.
 
     Insofar as indemnification by Synopsys for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of Synopsys pursuant to the provisions referenced in Prospectus or otherwise,
Synopsys has been advised that in the opinion of the Commission such
indemnification is against public policy as expressed in the Securities Act, and
is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by Synopsys of expenses
incurred or paid by a director, officer, or controlling person of Synopsys in
the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered hereunder, Synopsys will, unless in the opinion of its counsel the
matter has been settled by controlling precedent, submit to a court of
appropriate jurisdiction the question whether such indemnification by it is
against public policy as expressed in the Securities Act and will be governed by
the final adjudication of such issue.
 
                                       11
13
 
                                 SYNOPSYS, INC.
                       REGISTRATION STATEMENT ON FORM S-8
 
                                    PART II
 
                 INFORMATION REQUIRED IN REGISTRATION STATEMENT
 
ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.
 
     There are hereby incorporated by reference in this Registration Statement
the following documents and information heretofore filed with the Commission:
 
     (1) Synopsys's Annual Report on Form 10-K for the fiscal year ended
         September 30, 1997;
 
     (2) Synopsys's Quarterly Report on Form 10-Q for the quarter ended July 4,
         1998;
 
     (3) Synopsys's Quarterly Report on Form 10-Q for the quarter ended April 4,
         1998;
 
     (4) Synopsys's Quarterly Report on Form 10-Q for the quarter ended January
         3, 1998;
 
     (5) Synopsys's Current Report on Form 8-K dated November 16, 1998 relating
         to fourth quarter results;
 
     (6) Synopsys's Current Report on Form 8-K dated December 19, 1997 for the
         acquisition of Viewlogic Systems, Inc.; and
 
     (7) The description of the Synopsys's Common Stock contained in the
         Company's Registration Statement on Form 8-A, No. 000-19807, filed on
         January 24, 1992.
 
     All documents subsequently filed by Synopsys pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Exchange Act, prior to the filing of a post-effective
amendment which indicates that all securities registered have been sold or which
deregisters all securities then remaining unsold, shall be deemed to be
incorporated by reference in this Registration Statement and to be part hereof
from the date of filing of such documents.
 
ITEM 4. DESCRIPTION OF SECURITIES.
 
     Not applicable.
 
ITEM 5. INTERESTS OF NAMED EXPERTS AND COUNSEL.
 
     Not applicable.
 
ITEM 6. INDEMNIFICATION OF DIRECTORS AND OFFICERS.
 
     Section 145 of the Delaware General Corporation Law permits a corporation
to include in its charter documents, and in agreements between the corporation
and its directors and officers, provisions expanding the scope of
indemnification beyond that specifically provided by the current law.
 
     Article X of Synopsys's Restated Certificate of Incorporation provides for
the indemnification of directors to the fullest extent permissible under
Delaware Law.
 
     Article VII of Synopsys's Bylaws provides for the indemnification of
officers, directors and third parties to the fullest extent permissible under
Delaware Law, which provisions are deemed to be a contract between Synopsys and
each director and officer who serves in such capacity while such bylaw is in
effect.
 
     Synopsys has entered into indemnification agreements with its directors and
executive officers, in addition to the indemnification provided for in the
Registrant's Bylaws, and intends to enter into indemnification agreements with
any new directors and executive officers in the future.
 
                                      II-1
14
 
ITEM 7. EXEMPTION FROM REGISTRATION CLAIMED.
 
     The issuance of the shares being offered by the Form S-3 resale prospectus
were deemed to be exempt from registration under the Securities Act in reliance
on Section 4(2) of the Securities Act or Regulation D promulgated thereunder, or
Rule 701 promulgated under Section 3(b) of the Securities Act, as transactions
by an issuer not involving a public offering or transactions pursuant to
compensatory benefit plans and contracts relating to compensation as provided
under such Rule 701. The recipients of securities in each such transaction
represented their intention to acquire the securities for investment only and
not with a view to or for sale in connection with any distribution thereof and
appropriate legends were affixed to the share certificates and instruments
issued in such transactions. All recipients had adequate access, through their
relationship with Synopsys, to information about Synopsys.
 
ITEM 8. EXHIBITS.
EXHIBIT
NUMBER                            DESCRIPTION
-------                           -----------
5.1     Opinion of counsel as to legality of securities being
          registered.
 10.1     Everest Design Automation Inc. 1997 Stock Option/Stock
          Issuance Plan.
 10.2     Form of Stock Option Agreement under Everest Design
          Automation 1997 Stock Option/Stock Issuance Plan.
 10.3     Form of Everest Design Automation Inc. Founder's Restricted
          Stock Agreement.
 10.4     Form of Everest Design Automation Inc. Non-Statutory Option
          Agreement.
 23.1     Consent of counsel (contained in Exhibit 5.1).
 23.2     Independent Auditors' Consent.
 23.3     Independent Accountants' Consent.
 24.1     Power of Attorney (see page II-4).
ITEM 9. UNDERTAKINGS.
 
     A. Synopsys hereby undertakes:
 
          (1) To file, during any period in which offers or sales are being
     made, a post-effective amendment to this registration statement to include
     any material information with respect to the plan of distribution not
     previously disclosed in the Registration Statement or any material change
     to such information in the Registration Statement.
 
          (2) That, for the purpose of determining any liability under the
     Securities Act, each such post-effective amendment shall be deemed to be a
     new registration statement relating to the securities offered therein, and
     the offering of such securities at that time shall be deemed to be the
     initial bona fide offering thereof.
 
          (3) To remove from registration by means of a post-effective amendment
     any of the securities being registered which remain unsold at the
     termination of the offering.
 
     B. Synopsys hereby undertakes that, for purposes of determining any
liability under the Securities Act, each filing of Synopsys's annual report
pursuant to Section 13(a) or Section 15(d) of the Exchange Act (and, where
applicable, each filing of an employee benefit plan's annual report pursuant to
Section 15(d) of the Exchange Act) that is incorporated by reference in the
Registration Statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.
 
                                      II-2
15
 
     C. Insofar as indemnification for liabilities arising under the Securities
Act may be permitted to directors, officers and controlling persons of Synopsys
pursuant to law, Synopsys's Certificate of Incorporation, Bylaws or
indemnification agreements, Synopsys has been informed that in the opinion of
the Commission such indemnification is against public policy as expressed in the
Securities Act and is therefore unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by Synopsys of
expenses incurred or paid by a director, officer or controlling person of
Synopsys in a successful defense of any action, suit or proceeding) is asserted
by such director, officer or controlling person in connection with the
securities being registered hereunder, Synopsys will, unless in the opinion of
its counsel the matter has already been settled by controlling precedent, submit
to a court of appropriate jurisdiction the question of whether such
indemnification by it is against public policy as expressed in the Securities
Act and will be governed by the final adjudication of such issue.
 
                                      II-3
16
 
                                   SIGNATURES
 
     Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8/S-3 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Mountain View, State of California, on this 14th day
of December, 1998.
 
                                          SYNOPSYS, INC.
 
                                          By:      /s/ AART J. DE GEUS
                                            ------------------------------------
                                                      Aart J. de Geus
                                                  Chief Executive Officer
 
                               POWER OF ATTORNEY
 
     KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Aart J. de Geus and David Sugishita, and
each of them, as his or her attorney-in-fact, with full power of substitution in
each, for him or her in any and all capacities to sign any amendments to this
Registration Statement on Form S-8/S-3, and to file the same, with exhibits
thereto and other documents in connection therewith, with the Securities and
Exchange Commission, hereby ratifying and confirming all that said
attorney-in-fact, or his substitutes, may do or cause to be done by virtue
hereof.
 
     Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed below by the following persons in the
capacities and on the dates indicated.
SIGNATURE                                    TITLE                   DATE
                       ---------                                    -----                   ----
/s/ AART J. DE GEUS                                       Chief Executive Officer     December 14 1998
--------------------------------------------------------  (Principal Executive
Aart J. de Geus                                           Officer) and Chairman of
                                                          the Board of Directors
 
/s/ CHI-FOON CHAN                                         President, Chief Operating  December 14, 1998
--------------------------------------------------------  Officer and Director
Chi-Foon Chan
 
/s/ WILLIAM W. LATTIN                                     Executive Vice President    December 14, 1998
--------------------------------------------------------  and Director
William W. Lattin
 
/s/ DEBORAH COLEMAN                                       Director                    December 14, 1998
--------------------------------------------------------
Deborah Coleman
 
/s/ HARVEY C. JONES, JR.                                  Director                    December 14, 1998
--------------------------------------------------------
Harvey C. Jones, Jr.
 
/s/ A. RICHARD NEWTON                                     Director                    December 14, 1998
--------------------------------------------------------
A. Richard Newton
 
/s/ STEVEN C. WALSKE                                      Director                    December 14, 1998
--------------------------------------------------------
Steven C. Walske
 
/s/ DAVID SUGISHITA                                       Chief Financial Officer     December 14, 1998
--------------------------------------------------------  (Principal Financial
David Sugishita                                           Officer)
II-4
17
 
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
 
                            ------------------------
 
                                    EXHIBITS
                            ------------------------
 
                     REGISTRATION STATEMENT ON FORM S-8/S-3
 
                                 SYNOPSYS, INC.
 
                               DECEMBER 14, 1998
 
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
18
 
                               INDEX TO EXHIBITS
EXHIBIT                                                                SEQUENTIALLY
NUMBER                           DESCRIPTION                           NUMBERED PAGE
-------                          -----------                           -------------
5.1  Opinion of counsel as to legality of securities being
         registered.
   10.1  Everest Design Automation Inc. 1997 Stock Option/Stock
         Issuance Plan.
   10.2  Form of Stock Option Agreement under Everest Design
         Automation 1997 Stock Option/Stock Issuance Plan.
   10.3  Form of Everest Design Automation Inc. Founder's Restricted
         Stock Agreement.
   10.4  Form of Everest Design Automation Inc. Non-Statutory Stock
         Option Agreement.
   23.1  Consent of counsel (contained in Exhibit 5.1).
   23.2  Independent Auditors' Consent.
   23.3  Independent Accountants' Consent.
   24.1  Power of Attorney (see page II-4).