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                                                                   EXHIBIT 10.5


                                 SUMMIT DESIGN, INC.
                                 EMPLOYMENT AGREEMENT


     This agreement (the "Agreement") is entered into on February 25, 1999, 
effective as of such date, between SUMMIT DESIGN, INC., a Delaware 
corporation (the "Company") and Larry J. Gerhard ("Summit").

1.   EMPLOYMENT AND DUTIES.  The Company hereby employs Gerhard to serve and 
perform in the role of Chairman and Chief Executive Officer; provided that, 
if the Company shall hire a new Chief Executive Officer prior to the 
expiration of this Agreement, the Company shall employ Gerhard as an advisor 
to assist the new Chief Executive Officer.  Gerhard agrees that while he is 
Chief Executive Officer, he will perform his duties to the best of his 
ability and devote full time and attention to the transaction of the 
Company's business.  In the event that the Company hires a new Chief 
Executive Officer, Gerhard agrees to devote such time and effort as is 
necessary to provide advisory services to the Chief Executive Officer.  

2.   TERM.

     (a)  This Agreement shall expire on December 31, 1999.  Gerhard hereby 
agrees that if he is still an employee of the Company on such date, he will 
resign his employment with the Company.  Both parties acknowledge that the 
employment created herein is employment "at-will" and may be terminated at 
any time with or without cause under the terms stated herein.  In addition, 
Gerhard agrees that on December 31, 1999, he will resign his positions as a 
member of the Board of Directors of the Company and a member of the Board of 
Directors of any of the Company's subsidiaries.

     (b)  Termination of this Agreement shall not release Gerhard from any 
obligations under Sections 5, 6, 7, and 8 hereof.

3.   COMPENSATION.  In consideration of the services to be performed by 
Gerhard, the Company agrees to pay Gerhard the compensation consisting of the 
following:

     (a)  Base Salary of $33,333.33 per month.                                
   

     (b)  All benefits as specified in the Company's handbook and that are in 
effect generally for the executive officers of the Company.  These benefits 
include 100% medical, dental and optical coverage for Gerhard and his wife 
and children under the Company's medical/dental/optical plans, disability, 
accidental death and dismemberment and life insurance as specified in the 
employee handbook, the Company sponsored 401(k) retirement savings plan as 
provided to all employees and four (4) weeks paid time off per year as 
specified in the Employee handbook.  Gerhard shall also be entitled to 
reimbursement (including any necessary

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tax gross up) for plan deductibles and all other medical/dental/optical 
expenses not covered under the Company's benefit plans, except for elective 
cosmetic surgery.

     (c)  An allowance for car expenses of $1,000.00 per month.
     
4.   TERMINATION PAYMENT.  Beginning in the earlier of (i) the month that 
Gerhard's employment is terminated as a result of Gerhard's death or 
disability; (ii) the month that Summit terminates Gerhard's employment for 
any reason; or (iii) January 2000, the Company shall pay Gerhard $33,333.33 
per month plus all benefits set forth in Sections 3(b) and 3(c) except 
participation in the 401(k) retirement savings plan and paid time off.  This 
payment shall continue monthly for a total of twenty-four (24) months. 
Gerhard agrees that the foregoing payment satisfies in full all outstanding 
obligations owed to Gerhard by the Company.

5.   CONFIDENTIALITY.  Gerhard acknowledges that certain customer lists, 
design work, and related information, equipment, computer software, and other 
proprietary products and information, whether of a technical or non-technical 
nature, including but not limited to schematics, drawings, models, 
photographs, sketches, blueprints, printouts, and program listings of the 
Company (collectively referred to as "Technology"), were and will be 
developed by the Company at great expense and over lengthy periods of time, 
are secret and confidential, are unique and constitute the exclusive property 
and trade secrets of the Company, and any use or disclosure of such 
Technology, except in accordance with and under the provisions of this or any 
other written agreements between the parties, would be wrongful and would 
cause irreparable injury to the Company.  Gerhard hereby agrees that he will 
not, at any time, without the express written consent of the Company, 
publish, disclose, or divulge to any person, firm, or corporation, any of the 
Technology, nor will Gerhard use, directly or indirectly, for Gerhard's own 
benefit or the benefit of any other person, firm, or corporation, any of the 
Technology, except in accordance with this Agreement or other written 
agreements between the parties.

6.   INVENTIONS.  All original written materials, including without 
limitation programs, charts, schematics, drawings, tables, tapes, listings, 
and technical documentation, that have been or shall be prepared partially or 
solely by Gerhard in connection with employment by the Company shall belong 
exclusively to the Company.

7.   RETURN OF DOCUMENTS.  Gerhard acknowledges that all originals and copies 
of records, reports, documents, lists, plans, drawings, memoranda, notes, and 
other documentation related to the business of the Company or containing any 
confidential information of the Company shall be the sole and exclusive 
property of the Company, and shall be returned to the Company upon the 
termination of Gerhard's employment with the Company for any reason 
whatsoever or upon the written request of the Company.

8.   COMPLIANCE.  Gerhard agrees to comply with all of the Company's written
employment policies, guidelines, and procedures as contained in the Company's
employment manual, including revisions and additions thereto.

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9.   INJUNCTION.  In addition to all other legal rights and remedies, the 
Company shall be entitled to obtain from any court of competent jurisdiction 
preliminary and permanent injunctive relief of any actual or threatened 
violation of any term hereof without requirement of bond, as well as an 
equitable accounting of all profits or benefits arising out of such violation.

10.  WAIVER. The waiver of either party of a breach of any provision of this 
Agreement shall not operate or be construed as a waiver of any subsequent 
breach thereof.

11.  DISPUTES.  The legal relations of the parties hereunder, and all other 
matters hereunder, shall be governed by the laws of the State of Delaware. 
Unresolved disputes shall be resolved in a court of competent jurisdiction in 
Washington County, Oregon, and all parties hereto consent to the jurisdiction 
of such court.

12.  COMPENSATION COMMITTEE APPROVAL.  The effectiveness of this Agreement 
shall be subject to the approval of this Agreement by both members of the 
Compensation Committee, with such approval to be evidenced by their 
signatures to this Agreement.

13.  LIMITATION ON PAYMENTS.  In the event that the severance and other 
benefits provided for in this Agreement or otherwise payable to the Gerhard 
(i) constitute "parachute payments" within the meaning of Section 280G of the 
Internal Revenue Code of 1986, as amended (the "Code") and (ii) but for this 
Section, would be subject to the excise tax imposed by Section 4999 of the 
Code, then the Gerhard's severance benefits under Section 4 shall be payable 
either

     (i)  in full, or

     (ii) as to such lesser amount which would result in no portion of such 
severance benefits being subject to excise tax under Section 4999 of the 
Code, whichever of the foregoing amounts, taking into account the applicable 
federal, state and local income taxes and the excise tax imposed by Section 
4999, results in the receipt by the Gerhard on an after-tax basis, of the 
greatest amount of severance benefits under Section 4 notwithstanding that 
all or some portion of such severance benefits may be taxable under Section 
4999 of the Code.  Unless the Company and the Gerhard otherwise agree in 
writing, any determination required under this Section 13 shall be made in 
writing by the Company's independent public accountants (the "Accountants"), 
whose determination shall be conclusive and binding upon the Gerhard and the 
Company for all purposes.  For purposes of making the calculations required 
by this Section 13, the Accountants may make reasonable assumptions and 
approximations concerning applicable taxes and may rely on reasonable, good 
faith interpretations concerning the application of Sections 280G and 4999 of 
the Code.  The Company and the Gerhard shall furnish to the Accountants such 
information and documents as the Accountants may reasonably request in order 
to make a determination under this Section.  The Company shall bear all costs 
the Accountants may reasonably incur in connection with any calculations 
contemplated by this Section 13.

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14.  ENTIRE AGREEMENT.  This Agreement sets forth the entire agreement 
between the parties hereto, and fully supersedes any and all prior agreements 
or understandings, written or oral between the parties hereto pertaining to 
the subject matter hereof.  Without limiting the generality of the foregoing, 
the Employment Agreement dated as of August 1, 1997 between the Company and 
Gerhard is superseded in all respects by this Agreement.  No modification of 
amendment hereof is effective unless in writing and signed by both parties.

     

     IN WITNESS WHEREOF, the parties have executed this Agreement as of the 
date first above written.

"COMPANY":                         SUMMIT DESIGN, INC.
                                   a Delaware Corporation

                                   By:        /s/ Amihai Ben-David       
                                       -----------------------------------
                                   Name:     Amihai Ben-David

                                   Title:    Compsenation Committee Member

                                   
                                   By:          /s/ William V. Botts      
                                       -----------------------------------
                                   Name:     William V. Botts

                                   Title:    Compsenation Committee Member



"GERHARD":                                                                
                                               /s/ Larry J. Gerhard       
                                       -----------------------------------
                                                 Larry J. Gerhard


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