Document:

<PAGE>   1

                                                                   EXHIBIT 10.19

                           SOFTWARE LICENSE AGREEMENT

THIS SOFTWARE LICENSE AGREEMENT (hereinafter "Agreement") is entered into by and
between Computational Applications and System Integration, Inc., an Illinois
corporation, with its principal place of business at 2004 S. Wright Street,
Urbana, IL 61801 (hereinafter "CA&SI"), and Simplex Solutions, Inc., a Delaware
corporation, with its principal place of business at 521 Almanor Avenue,
Sunnyvale, CA 94086 (hereinafter "Simplex").

                            ARTICLE I - DEFINITIONS

1.1  "Effective Date" means the date the Agreement is fully signed by both the
parties.

1.2  The "Maintenance-Period" of this Agreement is as follows: The initial
Maintenance-Period shall be for one (1) year starting from the Effective Date of
this Agreement. [*]. In any event, the Maintenance-Period shall end no later
than two (2) years after the Effective Date of this Agreement.

1.3  "SOLVER" means CA&SI's software product known as [*], which includes,
without limitation, the multiple load case feature, and all other versions of
CA&SI's software product [*] that are delivered by CA&SI to Simplex during the
Maintenance-Period. SOLVER is a sparse direct solver for solving very sparse
systems of simultaneous linear equations with [*], but shall not include RSOLVE
or any other product or property of CA&SI. The current version of SOLVER is [*].

1.4  "Upgrade" means any subsequent released version of SOLVER.

1.5  "API" means the Applications Program Interface to SOLVER, as further
described in the Documentation.

1.6  "Bug" means any condition which (a) causes a hard error such as a bus error
or segmentation fault, and thereby causes SOLVER to crash or fail, or (b) causes
SOLVER to halt with an error condition other than a proper error indicating
Insufficient Memory of Insufficient Disk Space or Incorrect File Permissions or
Input Data Inconsistent, or (c) causes SOLVER to product a result that is not
within reasonable engineering tolerances of the solution to a properly inputted
system of very sparse simultaneous linear equations [*], provided in any case
that CA&SI can reproduce such phenomenon on its in-house platform(s) with
information supplied by Simplex.

1.7  "Documentation" means CA&SI's formal description of the API and of the
functionality, capabilities and limitations of SOLVER, as provided by CA&SI.

*Certain information on this page has been omitted and filed separately with
 the Commission. Confidential treatment has been requested with respect to the
 omitted portions.
<PAGE>   2
1.8  "Field of Use" means the field of integrated circuit electronic design
automation, which includes without limitation the use of resulting designs to
manufacture integrated circuit products.

1.9  "Source Code" means a collection of statements comprising a software
program, whether in written form or in magnetic or other machine-readable form,
and being intelligible in human-readable form, of SOLVER.

1.10 "Object Code" means machine readable machine language code of SOLVER
executable on a computer system, other than Source Code, including without
limitation linkable binary code as well as directly executable files.

1.11 "Term" means the time period beginning on the Effective Date of this
Agreement and ending upon termination of this Agreement in accordance with the
provisions herein.

                         ARTICLE II - SOFTWARE LICENSE

In consideration of the license fees to be paid by Simplex and its other
obligations under this Agreement, CA&SI hereby grants a [*] license to the
Source Code of SOLVER to Simplex subject to the terms and restrictions given
below and in the rest of this Agreement:

2.1  Subject to the other provisions in this Agreement, CA&SI grants to Simplex
a perpetual, irrevocable, worldwide, right and license to modify, copy, and use
the Source Code and functionality thereof [*], all of which rights may be
exercised solely in connection with or as incorporated into a Simplex software
product. It is understood that, subject to any restrictions set forth in this
Agreement, the foregoing right and license extends both to the non-functional
copyrightable expression in the Source Code as well as the algorithms,
functionality and techniques in the Source Code.

2.2  Subject to the other provisions in this Agreement, CA&SI grants to Simplex
the perpetual, irrevocable, worldwide, right to incorporate the Source Code or
portions thereof into Simplex's internal software configuration management
system.

2.3  CA&SI grants to Simplex the perpetual, irrevocable, worldwide right and
license to distribute, market, import, export, copy, offer for sublicensing and
sublicense SOLVER or [*], however only in Object Code form and only when
incorporated into a Simplex software product and solely for use in the Field of
Use. [*]

2.4  The geographic scope of this license is worldwide.

*Certain information on this page has been omitted and filed separately with
 the Commission. Confidential treatment has been requested with respect to the
 omitted portions.

                                       2
<PAGE>   3

2.5 Simplex will not use or incorporate SOLVER in a way that would allow the
user of any Simplex software product to [*] allow such user access to the API.

Notwithstanding the foregoing, the following restrictions shall apply:

2.6 Simplex shall not provide, disclose or sublicense the Source Code [*] in
source code form to any third party except to the extent expressly permitted in
Section 2.6, 2.7, 10.1, 10.2 or 12.1 hereof. Simplex may place the Source Code,
[*] in escrow, subject to the following conditions and limitations, which shall
be set forth in the documentation establishing such escrow, which documentation
shall be delivered promptly to CA&SI upon request:

     (a) The Source Code shall be escrowed only as an integral part of, and
     together with, source code for a licensed Simplex product, solely for the
     benefit of a licensee of such Simplex product;

     (b) Such escrow shall be administered by a reputable third party software
     escrow agent;

     (c) The terms of such escrow shall strictly limit the use of the Source
     Code by any releasee thereof to supporting and maintaining the licensed
     Simplex product which includes SOLVER or the respective modification or
     derivative thereof;

     (d) Prior to deposit of the Source Code in escrow, each potential releasee
     of the Source Code shall agree in writing, for the benefit of CA&SI, that
     such releasee (i) shall not provide the Source Code [*] to any third party
     and (ii) shall be subject to and bound by all of the conditions,
     restrictions and limitations on the use of such Source Code and proprietary
     information set forth in this Agreement in the same manner as applies to
     Simplex. The Object Code corresponding to any such Source Code [*] shall be
     subject to the same terms and conditions as apply to Simplex's object code
     for the licensed Simplex product, and shall be subject to and bound by all
     of the conditions, restrictions and limitations on the use of such Object
     Code and proprietary information set forth in this Agreement in the same
     manner as applies to Simplex;

     (e) The Source Code will be released only as an integral part of, and
     contemporaneous with, any release of source code for the Simplex product
     incorporating the Source Code; and

     (f) Triggering events for release of the escrow will be limited to the
     following events, except as agreed to in writing by CA&SI: (i) Simplex
     fails to conduct business

*Certain information on this page has been omitted and filed separately with
 the Commission. Confidential treatment has been requested with respect to the
 omitted portions.

                                       3
<PAGE>   4

      in the ordinary course and fails to support and maintain its products for
      a period of thirty (30) days or more after demand therefor by its
      licensee, (ii) the bankruptcy, liquidation or dissolution of Simplex,
      Simplex making an assignment for the benefit of creditors, or upon the
      appointment of a receiver or trustee of Simplex pursuant to any state or
      federal bankruptcy law or similar law relating to creditor's rights
      generally.

2.7   Access to the Source Code will be provided only to Simplex personnel, at
the facilities of Simplex or other secure facilities where Simplex permits
access to source code for its own products, including without limitation
off-size storage and backups, who (a) have a need for such access in order to
utilize the Source Code consistent with this Agreement, and (b) have been
apprised of the terms of this Agreement regarding restrictions on use and
disclosure of the Source Code.

2.8   CA&SI retains sole title and all intellectual property rights to SOLVER,
its Source Code and Object Code, and all algorithms, data structures and
implementation techniques in the Source Code. [*]

2.9   Periodically (at least once every four months) solely during the
Maintenance Period Simplex shall run SOLVER benchmarks on representative
problems and on representative platforms and provide the (jobname).PCS
statistics files back to CA&SI. CA&SI shall have the right to use these files
and the data contained therein for any purpose suitable for its business.

2.10  Nothing herein shall constitute or be deemed a grant of rights or
limitation on, nor shall this Agreement relate to, any other software, product,
source code, or object code currently licensed or sublicensed from CA&SI by
Simplex, including specifically, but without limitation of the generality of
the foregoing, any prior arrangement concerning RSOLVE or any other property
described in that certain Software License Agreement between the parties dated
May 1, 1997.

              ARTICLE III - WARRANTY AND LIMITATIONS ON LIABILITY

3.1   Simplex acknowledges SOLVER is provided AS IS and without warranties of
any kind, except as set out in paragraph 4.1. Specifically, Simplex
acknowledges that SOLVER IS PROVIDED WITHOUT ANY EXPRESS OR IMPLIED WARRANTY,
INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR

*Certain information on this page has been omitted and filed separately with
 the Commission. Confidential treatment has been requested with respect to the
 omitted portions.

                                       4
<PAGE>   5

PURPOSE. CA&SI has no obligations with regard to any error or defect claimed
with regard to SOLVER except as provided for in paragraph 7.3.

3.2  Simplex shall assure that, with respect to each customer with whom Simplex
enters an agreement by which Simplex sublicenses SOLVER, CA&SI shall be included
(either by name or as a Licensor of Simplex) under such agreement to all
limitations from liability for errors or otherwise with respect to its SOLVER as
is provided to Simplex with respect to its software. In no event shall either
party be liable for any indirect, special, incidental or consequential damages
of any nature, including lost profits, whether or not such party shall have been
advised of the possibility of the same, except to the extent arising out of
disclosure of the Source Code by Simplex in material breach of this Agreement
which results in loss of CA&SI's trade secrets or proprietary rights to the
Source Code and is not, or cannot be, cured within a reasonable period of time.
CA&SI shall have no liability to any third party to which Simplex licenses any
software product that may contain SOLVER or any version thereof. Simplex shall
indemnify, save and hold harmless CA&SI from and against any and all loss, cost,
or claim arising from or in connection with, any use or sublicensure of SOLVER
by Simplex or its permitted assignees, licensees or end-users, except to the
extent arising out of or related to breach of any express warranty of CA&SI
under ARTICLE IV or CA&SI's knowing or willful misconduct. Simplex's obligations
under this paragraph 3.2 are subject to the following conditions: (i) CA&SI
shall permit Simplex to control the litigation and settlement; (ii) CA&SI agrees
to notify Simplex upon knowledge of any claim, suit, action, or proceeding for
which it may entitled for indemnification under this agreement; (iii) CA&SI
agrees to provide reasonable assistance to Simplex at Simplex's expense, in
defense of the same; and (iv) CA&SI will not enter into any settlement agreement
or otherwise settle any such claim without Simplex's prior consent or request.

3.3  In no event shall CA&SI have any liability with respect to any error or
malfunction which results directly or indirectly from: a) any change of any
nature made by Simplex or any third party; b) failure by Simplex to follow any
of CA&SI's written instructions with regard to the use of SOLVER; or c) the
attachment, integration or incorporation of any other software program in or
with SOLVER or the incorporation of SOLVER in or with any other software
program. Neither party shall have any liability resulting directly or indirectly
from any cause beyond such party's reasonable control, including without
limitation, any weather or power related problems, any acts or omissions by a
communications carrier or any other event of force majeure.

                 ARTICLE IV -- INTELLECTUAL PROPERTY INDEMNITY

4.1  CA&SI represents and warrants that it owns SOLVER and has full authority to
grant the rights stated herein to Simplex without the consent or authority of
any third party, and that SOLVER and the license granted hereby do not infringe
any copyright, trade secret, patent, contract or other right of any third party.
CA&SI will defend or settle any suit brought by a third party against Simplex
alleging SOLVER violates any such right. CA&SI shall not enter

                                       5
<PAGE>   6

into any settlement without the written consent of Simplex, which consent shall
not be unreasonably withheld or delayed. CA&SI's indemnification obligation
under this ARTICLE IV shall not apply to any settlement entered into by Simplex
without the written consent of CA&SI, which consent shall not be unreasonably
withheld or delayed. At its option CA&SI may provide Simplex with a version of
SOLVER which, to the extent technically practicable, contains equivalent
functionality and performance and does not infringe or result in such a
violation. CA&SI shall indemnify and hold Simplex harmless for all loss, cost,
reasonable expense (including attorney's fees), damage or judgment related to or
arising out of such a claim.

                            ARTICLE V - LICENSE FEES

5.1  Simplex will pay CA&SI a license fee of [*] within [*] of the Effective
Date of this Agreement. Upon payment of such fee and the maintenance fee for the
first year as specified in paragraph 7.2, the rights and licenses granted to
Simplex under ARTICLE II shall be [*].

                             ARTICLE VI - PUBLICITY

6.1  Simplex agrees that the CA&SI copyright notice and disclaimer provided as
part of the Source Code will be printed to and displayed in the program output
whenever SOLVER is invoked. Such copyright notice and disclaimer may be
reasonably modified or amended from time to time by CA&SI as necessary to update
factual and disclaimer information and maintain the legal correctness of such
copyright notice and disclaimer. Simplex also agrees to give due attribution to
CA&SI as the provider of SOLVER in any online or printed documentation of any
product that incorporates or uses SOLVER or any portion thereof. CA&SI grants to
Simplex a non-exclusive, royalty free, worldwide right and license to use CA&SI
trademarks in connection with the marketing, promotion, sublicensing and
distribution of Simplex products that include SOLVER or any portions thereof.
Simplex agrees to use the symbol "TM" with presentations of CA&SI trademarks
including CA&SI and [*].

                ARTICLE VII - TECHNICAL SUPPORT AND MAINTENANCE

7.1  Any technical support or maintenance for SOLVER provided by CA&SI will be
provided directly to Simplex and not to Simplex customers.

7.2  Simplex will pay CA&SI an initial maintenance fee of [*] within [*] of the
Effective Date of this agreement. If the Maintenance-Period is extended for a
year as per paragraph 1.2 then Simplex will pay CA&SI an additional maintenance
extension fee of [*] within [*] of the anniversary of the Effective Date of this
Agreement.

*Certain information on this page has been omitted and filed separately with
 the Commission. Confidential treatment has been requested with respect to the
 omitted portions.

                                       6
<PAGE>   7

7.3 Subject to all of the terms, conditions and limitations set forth herein,
and in consideration of the maintenance fees paid to CA&SI hereunder, CA&SI
will provide Upgrades and Bug fixes for SOLVER to Simplex during the
Maintenance-Period. The procedure for fixing bugs will be as follows: Simplex
will provide sufficient information to CA&SI to reproduce a Bug on an in-house
platform, and it is expected that the Bug will probably be fixed by the next
release of SOLVER. No Upgrades or Bug fixes will be provided after the
Maintenance-Period.

7.4 CA&SI is not obligated to provide any Upgrades or Bug Fixes to Simplex
unless CA&SI receives timely payment of maintenance fees as per paragraph 7.2
or accepts late payment.

7.5 Any and all Upgrades delivered or otherwise made available to Simplex
pursuant to this Agreement shall be conditioned upon and subject to all of the
terms, restrictions, conditions and limitations applicable to SOLVER, as set
forth in the remainder of this Agreement.

7.6 CA&SI's support obligations hereunder are strictly limited to Upgrades and
Bug fixes for SOLVER. During the Maintenance-Period CA&SI will provide other
technical services to Simplex on a consulting basis subject to the following
terms and conditions: (i) CA&SI must have personnel available for such services,
in the sole determination of CA&SI; (ii) Simplex shall pay CA&SI an additional
consulting fee of [*] per day or any portion thereof and such fee shall not
include any travel expenses; and (iii) Simplex shall separately reimburse CA&SI
for all reasonable travel-expenses incurred.

7.7 Termination of this Agreement in accordance with the provisions of this
agreement will automatically terminate all of CA&SI's maintenance and support
obligations hereunder.

                           ARTICLE VIII - TERMINATION

8.1 In addition to any other remedies available, each party shall have the
right to terminate this Agreement as a result of a material breach by the other
party of any of the provisions of this Agreement, which breach remains uncured
more than thirty (30) days after written notice which specifically sets forth
the nature and circumstances of the breach and references the applicable
provisions of this agreement. Each party shall also be entitled to equitable
remedies as required to enforce its rights under this Agreement. In addition,
Simplex shall have the right to terminate this Agreement for its convenience
upon ninety (90) days advance written notice to CA&SI.

8.2 In the event of termination of this Agreement, Simplex may retain a copy of
the Source Code [*]. Documentation and other information it has received from
CA&SI which may be used solely for the purpose of providing continuing support
for sublicenses of SOLVER [*] granted prior to the termination date. Simplex
shall not make or keep any other copy of the Source Code [*] and any related
information, and agrees not to disclose or use the same for any other purpose,
directly or indirectly. Simplex reserves the

*Certain information on this page has been omitted and filed separately with
 the Commission. Confidential treatment has been requested with respect to the
 omitted portions.

                                       7
<PAGE>   8

right to segregate and use without restriction independent source code meeting
the requirements of paragraph 11.1. The parties agree such termination will not
affect any sublicense of the SOLVER [*] that Simplex has granted prior to the
termination date, but Simplex will have no right to grant or renew any further
sublicenses. Notwithstanding anything to the contrary in this Agreement,
termination of this Agreement will terminate all rights and licenses granted to
Simplex under this Agreement except those specified in paragraph 8.2, 14.8 and
the right to place Source Code under escrow granted in paragraph 2.6 for the
benefit of existing sublicensees prior to termination.

8.3  If this Agreement is terminated in accordance with the provisions of this
Agreement after the Acceptance Period in paragraph 9.1 then CA&SI shall have
the right to receive and retain all license fees which have become due and
payable under ARTICLE V and all maintenance fees which have become due and
payable under paragraph 7.2 prior to termination.

                         ARTICLE IX - FORM AND DELIVERY

9.1  The Source Code will be provided as C language source code. A snap shot of
the Source Code will be delivered by CA&SI to Simplex together with the
Documentation within one (1) week of the Effective Date of this Agreement. This
snap shot will contain the multiple load case feature. There will be an
"Acceptance Period" of three (3) weeks starting from the date the Source Code
is delivered to Simplex. During the Acceptance Period Simplex has the option of
not accepting the Source Code and terminating this Agreement by giving a
written notice to CA&SI. If Simplex terminates this Agreement during the
Acceptance Period in this manner then Simplex will be entitled to a full refund
of any of the license fees paid to CA&SI under ARTICLE V and any of the
maintenance fees paid to CA&SI under paragraph 7.2. If no notice of termination
is received by CA&SI during the Acceptance Period then the Source Code will be
deemed to have been accepted by Simplex. If Simplex terminates this Agreement
before the end of the Acceptance Period then Simplex will destroy all copies of
the Source Code. Documentation and other information provided by CA&SI and
Simplex will have no right to grant any sublicenses of SOLVER.

                 ARTICLE X - CONFIDENTIALITY AND NON-DISCLOSURE

10.1 Simplex agrees that the Source Code and the Documentation for SOLVER are
and will be treated by Simplex as confidential and trade secret property owned
by CA&SI, and title and all rights of ownership shall remain with CA&SI. Any
information Simplex may obtain, directly or indirectly, with regard to the
Source Code or Documentation or any other information, that is clearly marked
as confidential or proprietary information of CA&SI, shall be kept confidential
by Simplex and shall not be disclosed, directly or indirectly, to any third
party. Simplex agrees to immediately report to CA&SI any unauthorized use or
disclosure of

*Certain information on this page has been omitted and filed separately with
 the Commission. Confidential treatment has been requested with respect to the
 omitted portions.

                                       8
<PAGE>   9
CA&SI confidential or proprietary information, whether or not such use or
disclosure is the fault of Simplex.

10.2 Notwithstanding anything to the contrary in this Agreement, information in
the following categories shall not be deemed proprietary to CA&SI and the
confidentiality restrictions in this Agreement shall not apply to: (i)
information that is otherwise proprietary information hereunder that is in or
comes into the public domain through no direct or indirect act or omission of
Simplex; (ii) information that is independently developed by or for Simplex, or
is developed and provided to Simplex by one or more third parties, without use
of proprietary information disclosed to Simplex and without any breach of this
Agreement; (iii) information which is in the possession of Simplex at the time
of disclosure by CA&SI, or (iv) information that is specifically approved by
CA&SI for release to third parties not bound by written confidentiality
provisions by written authorization by CA&SI. Notwithstanding anything to the
contrary in this Agreement, Simplex may disclose confidential or proprietary
information of CA&SI to the extent required by law or by order of any court or
governmental agency, provided that, to the extent it may legally do so, Simplex
gives reasonable advance notice to CA&SI and uses its reasonable efforts to
secure confidential treatment of such information prior to its disclosure
(whether through protective orders or otherwise).

                         ARTICLE XI - SIMILAR PRODUCTS

11.1 Nothing in this Agreement shall limit Simplex's right to (i) use
information which is generally available to third parties without violation of
any proprietary or intellectual property rights of CA&SI and without any breach
of this Agreement; or (ii) develop, acquire, or market other software or
products having functionality similar to that of SOLVER, provided Simplex can
show that such software has been developed independently without use or aid,
directly or indirectly, of the SOLVER Source Code, Documentation, algorithms
and data structures in the Source Code, or any other confidential or
proprietary information of CA&SI obtained by Simplex.

                            ARTICLE XII - ASSIGNMENT

12.1 This Agreement shall be binding upon and enure to the benefit of the
parties hereto, their successors and any permitted assigns. Simplex shall not
have the right to assign or otherwise transfer any of its rights or obligations
under this Agreement. Notwithstanding the foregoing, a merger or acquisition of
substantially all of the business to which this Agreement relates (whether by
sale of stock, sale of assets or otherwise) of either of the parties shall not
violate this prohibition against assignment, provided the merger or acquisition
agreement and appropriate state law provide that the acquiror or the successor
by merger, as appropriate, shall be fully liable for performance of all of the
terms and provisions of this Agreement and the original party shall not be
released from such performance to the extent the original party survives as a
separate legal entity. In the event of a transfer of Simplex's licenses in
connection with such a merger or acquisition, it is understood that the
licenses granted by

                                       9
<PAGE>   10

CA&SI to Simplex under this Agreement will be transferred to the respective
acquiror or successor and will not be retained by Simplex. It is understood
that at any given time there will be only one licensee who will hold the rights
and licenses granted by CA&SI under this Agreement and that licensee will be
subject to all the obligations and restrictions under this Agreement.

                       ARTICLE XIII - EXPORT RESTRICTIONS

13.1 Simplex acknowledges having reviewed and understanding the provisions of
the Export Administration Regulations as currently in effect in the United
States and agrees it will not export or re-export, directly or indirectly, any
software product that uses or incorporates any version of SOLVER to any country
to which such export, or re-export, is prohibited under the Regulations.
Simplex further agrees that it will obtain any and all export licenses
necessary to allow the export or re-export of any software products using or
incorporating the SOLVER in the event the destination country to which such
export is to be made requires any such license, Simplex agrees to indemnify and
hold CA&SI harmless from and against any and all losses or costs incurred as a
result of Simplex's failure to comply with the provisions of this article.

                          ARTICLE XIV - MISCELLANEOUS

14.1 This Agreement constitutes the entire understanding between the parties
and supersedes any discussions, negotiations, understandings or prior
agreements (if any) with respect to the subject matter hereof. There are no
representations, promises, warranties or understandings relied upon by the
parties which are not contained herein. This Agreement may be modified only by
a writing signed by both parties.

14.2 The failure by either party to insist upon strict enforcement of any terms
and conditions of this Agreement shall not constitute a waiver of such right
with regard to the same or any subsequent breach at a later date. If any
provision of this Agreement is held to be unenforceable, by a court of
competent jurisdiction or arbitrator pursuant to Section 14.6, such decision
shall not affect the validity or enforceability of the remaining provisions,
which shall be modified only to the extent required to modify or strike the
unenforceable provisions.

14.3 In the event of a default by either party under the terms of this
Agreement, the nondefaulting party shall be entitled to recover all costs,
including reasonable attorneys' fees, incurred in enforcing its rights under
this Agreement.

14.4 Any notice required or permitted hereunder shall be personally delivered
or mailed by certified mail, return receipt requested, and shall be effective
upon the earlier of receipt or three (3) days after being so mailed. The
addresses of the parties for notice are the addresses

                                       10
<PAGE>   11
set forth on page one, unless either party gives written notice of a new address
for this purpose.

14.5 The captions used in this Agreement are for convenience only and shall not
control or affect the meaning or construction of the provisions of this
Agreement.

14.6 Any controversy or claim arising out of this Agreement or its breach, shall
be settled by binding arbitration in Champaign, Illinois. A single arbitrator
shall be chosen by mutual agreement of the parties within fifteen (15) days
after the date on which the parties determine in good faith that they will be
unable to agree as to the settlement of the controversy or claim. In the event
the parties cannot mutually agree upon an arbitrator, each party shall select an
arbitrator and the two arbitrators so selected shall select a third arbitrator.
The decision of the arbitrator, or a majority of the panel of three arbitrators,
as appropriate, shall be made within thirty (30) days of the selection of the
arbitrator(s), and shall be final and binding upon the parties. Judgment on the
arbitration decision may be entered in the appropriate court as provided in this
Agreement. The arbitration shall be governed by and conducted in accordance with
the rules of the American Arbitration Association for commercial arbitration.
The cost of arbitration shall be borne equally by the parties, unless the
arbitration decision shall apportion the costs otherwise.

14.7 None of the provisions of this Agreement shall be for the benefit of or
enforceable by any third party, including specifically, but without limitation
of the generality of the foregoing, any sub-licensee of Simplex.

14.8 Notwithstanding any provision herein to the contrary, the duties,
undertakings, indemnities and other obligations of Simplex set forth in Sections
2.3, 2.5, 2.6, 2.7, and the duties, rights, undertakings, indemnities and other
obligations of both parties set forth in 2.8, 2.9 (last sentence only), 3.2,
3.3, 4.1, 6.1, 8.2, 9.1, 10.1, 10.2, 11.1, 12.1, 13.1, and ARTICLE XIV hereof,
shall survive the execution, delivery, performance and termination of this
Agreement in perpetuity.

14.9 This Agreement shall be governed by and construed in accordance with the
laws of the State of Illinois, without regard to its choice of law provisions.
The parties agree any litigation involving this Agreement shall be brought in
either state or federal court located in Champaign County, Illinois, unless
CA&SI shall otherwise agree in writing in advance.

14.10 Simplex shall be responsible for all taxes of any nature arising as a
result of distribution of any products that use or incorporate any version of
SOLVER, with the exception of taxes on CA&SI based upon CA&SI's taxable income
from payments hereunder.

14.11 Any and all restrictions on the licensure, sub-licensure, disclosure,
modification, distribution, marketing, and other use of SOLVER, the Source Code,
the Object Code, and the Documentation by Simplex shall, except as provided in a
writing signed by a duly authorized

                                       11

<PAGE>   12

representative of CA&SI with specific reference to this provision, apply to any
upgrade or subsequent version of SOLVER which may be licensed or delivered to
Simplex under this agreement.

IN WITNESS WHEREOF, this Agreement has become effective on the date of the
latest signature of the parties as set forth below.

Computational Applications and                Simplex Solutions, Inc., a
Systems Integration, Inc., an Illinois        Delaware Corporation
corporation

By: P.M. VAIDYA                               By: [SIGNATURE ILLEGIBLE]
   --------------------------------              -------------------------------

Title: President                              Title: President & CEO
      -----------------------------                 ----------------------------

Name: Pravin M. Vaidya                        Name: [SIGNATURE ILLEGIBLE]
     ------------------------------                -----------------------------

Date: July 14, 1998                           Date: July 15, 1998
     ------------------------------                -----------------------------

                                       12<PAGE>   1
                                                                EXHIBIT 10.20

                                 [DIGITAL LOGO]

                               AGREEMENT BETWEEN

                            SIMPLEX SOLUTIONS, INC.

                                      AND

                         DIGITAL EQUIPMENT CORPORATION

                           FOR LICENSING OF CAD TOOLS

License # SEG/CAD-92195-1                              Dated September 21, 1995
<PAGE>   2

Table of Contents

1.0       DEFINITIONS

2.0       TITLE AND LICENSE GRANTS

3.0       LICENSE FEES AND PAYMENTS (CONSIDERATION)

4.0       CONFIDENTIALITY

5.0       UPDATES, TRAINING AND SUPPORT SERVICES

6.0       TECHNOLOGY TRANSFER

7.0       WARRANTIES

8.0       LIMITATION OF LIABILITY

9.0       REMEDIES

10.0      INJUNCTIVE RELIEF

11.0      TERMINATION

12.0      NOTICES

13.0      GENERAL TERMS

APPENDIX A LICENSED SOFTWARE AND DOCUMENTATION

<PAGE>   3

                           SOFTWARE LICENSE AGREEMENT

This Agreement is entered into as of September 21, 1995 (EFFECTIVE DATE) by and
between Digital Semiconductor a business unit of Digital Equipment Corporation,
a Massachusetts Corporation with principle offices at 111 Powdermill Road,
Maynard, Massachusetts 01754-1458 (hereinafter "DIGITAL") and Simplex
Solutions, Inc., a Delaware Corporation with principal offices at 2540 North
First Street, Suite 302, San Jose, CA 95131 ("SIMPLEX").

SIMPLEX desires to acquire an EXCLUSIVE LICENSE, except for Digital
Semiconductor's own internal use, for [*] after which this LICENSE reverts to a
NON-EXCLUSIVE LICENSE, to use, modify, develop and create derivative works of
the LICENSED SOFTWARE in source code and binary format, as defined in Appendix A
in order to create SIMPLEX SOFTWARE, and to market, promote and distribute, in
binary format only, such SIMPLEX SOFTWARE internationally.

DIGITAL desires to grant SIMPLEX such EXCLUSIVE LICENSE, except for Digital
Semiconductor's own internal use, for [*] after which this LICENSE reverts to a
NON-EXCLUSIVE LICENSE to use in source code format, and a limited non-exclusive
right to sublicense in binary format only the LICENSED SOFTWARE, as defined in
Appendix A, as part of SIMPLEX SOFTWARE subject to the terms and conditions
hereinafter set forth.

Therefore, for and in consideration of the mutual covenants expressed herein
and other good and valuable consideration, except which the parties hereby
acknowledge, the parties hereby agree as follows:

1.      ARTICLE 1 - DEFINITIONS

As used in this Agreement, the following terms shall have the following
respective meanings:

        1.1.    CONTRACT YEAR shall mean the twelve month period beginning on
                the first anniversary date of the EFFECTIVE DATE and on each
                anniversary of the EFFECTIVE DATE thereafter. CONTRACT YEARS
                shall be referred to by the calendar year in which such CONTRACT
                YEAR began.

        1.2.    DIGITAL and SIMPLEX are hereafter occasionally referred to as
                "party" or "parties" as indicated by the context.

        1.3.    INTELLECTUAL PROPERTY RIGHTS shall mean any of the following
                rights owned or licensed by DIGITAL with respect to LICENSED
                SOFTWARE as delivered hereunder during the term hereof.

                1.3.1.  All rights, title and interests in all Letters Patent
                        including any reissue, division, continuation or
                        continuation-in-part applications throughout the world
                        now or hereafter filed; and

                1.3.2.  All mask work rights including mask work registration
                        rights, all copyright rights, and all other literary
                        property and author rights whether or not copyrightable;
                        and all rights, title and interests in all copyrights,
                        mask work registrations and copyrighted interests; and

                1.3.3.  All rights, title and interests in all know-how and
                        show-how whether or not protectable by patent,
                        copyright, mask work registration or trade secret.

        1.4.    LICENSED SOFTWARE shall mean DIGITAL's CAD software tools in
                both object code and source code forms, as more particularly
                identified and described in Appendix A hereto and shall also
                include DIGITAL's User Guides and reference manuals listed in
                Appendix A.

        1.5.    EXCLUSIVE LICENSE shall mean a license which permits SIMPLEX to
                use the LICENSED SOFTWARE as licensed, but which does not
                prohibit DIGITAL in any manner from making, using and selling
                LICENSED SOFTWARE and products embodying the LICENSED SOFTWARE
                throughout the world, and which does not prohibit DIGITAL from
                granting non-exclusive rights to third parties to use

*Certain information on this page has been omitted and filed separately with
 the Commission. Confidential treatment has been requested with respect to the
 omitted portions.
<PAGE>   4
          LICENSED SOFTWARE for any purpose throughout the world, except for the
          first four (4) years of this LICENSE, for which time Digital shall not
          license any other third party.
          1.5.1.    The term "use" as employed in Article 1.4 above shall
                    include but not be limited to the rights to design,
                    implement, develop, copy, reproduce, manufacture, package,
                    install, operate, test, correct, maintain, repair, enhance,
                    extend, translate, transliterate, and create or sublicense
                    other derivative works.
     1.6. SIMPLEX SOFTWARE shall mean SIMPLEX's [*] (which will incorporate the
          LICENSED SOFTWARE) and [*] (which will not incorporate the LICENSED
          SOFTWARE) software programs as well as any other software owned or
          marketing by SIMPLEX which may incorporate LICENSED SOFTWARE,
          including any manuals and related documentation.
     1.7. TERM shall mean the term of this Agreement commencing on the EFFECTIVE
          DATE and continuing thereafter for a term of [*] years or until
          otherwise terminated in accordance with Article 10 below. Prior to the
          end of the TERM of this Agreement the parties shall confer and
          negotiate in good faith any extension of this Agreement.
     1.8. USE SUBLICENSE shall mean any agreement or arrangement between SIMPLEX
          and any of its end user customers for the lease, license or use of
          SIMPLEX SOFTWARE. USE SUBLICENSES shall only grant end users the right
          to use the SIMPLEX SOFTWARE in binary format.
     1.9. References to an Article in this Agreement shall be deemed to include
          all Articles numerically depending therefrom. For example, a reference
          to Article 2.2 shall be deemed to include Articles 2.2.1 and 2.2.2,
          and a reference to Article 3 shall be deemed to include Article 3.1.

2.   ARTICLE 2 - TITLE AND LICENSE GRANTS
     2.1. Subject to the limited EXCLUSIVE LICENSE granted to SIMPLEX as
          expressly set forth in this Article 2, DIGITAL Owns and shall retain
          all rights, title and interests including INTELLECTUAL PROPERTY RIGHTS
          in the LICENSED SOFTWARE. SIMPLEX shall retain ownership of all
          corrections, adaptations, enhancements and extensions to the SIMPLEX
          SOFTWARE, as well as any derivative works created from the LICENSED
          SOFTWARE, developed by or for SIMPLEX pursuant to the rights licensed
          hereunder.
     2.2. DIGITAL agrees to grant and hereby grants to SIMPLEX under DIGITAL's
          INTELLECTUAL PROPERTY RIGHTS, and subject to the terms of Article 4
          below, a perpetual, irrevocable, worldwide EXCLUSIVE LICENSE, except
          for Digital Semiconductor's own internal use, to use, reproduce,
          develop, modify and create derivative works of the LICENSED SOFTWARE
          in order to create SIMPLEX SOFTWARE, and to use, reproduce,
          distribute, perform and display the SIMPLEX SOFTWARE in binary code
          format only pursuant to the USE SUBLICENSES with the right to further
          sublicense in binary format only to any tier as may be necessary to
          distribute SIMPLEX SOFTWARE to end user customers.
          2.2.1.    SIMPLEX shall label all SIMPLEX SOFTWARE which includes
                    LICENSED SOFTWARE in whole or in part with the following
                    notice: "Portions of this product incorporates technology
                    licensed from Digital Equipment Corporation".
          2.2.2.    In addition to the foregoing, SIMPLEX shall have the right
                    to transfer possession of the source code of the LICENSED
                    SOFTWARE as incorporated in the SIMPLEX SOFTWARE as part of
                    a source code escrow of the SIMPLEX SOFTWARE established for
                    the benefit of end user customers to allow such end users to
                    use such software solely to support and maintain SIMPLEX
                    SOFTWARE in their possession in the event SIMPLEX is unable
                    to do so, in each case subject to escrow terms

*Certain information on this page has been omitted and filed separately with
 the Commission. Confidential treatment has been requested with respect to the
 omitted portions.

                                                                               2
<PAGE>   5

            approved by DIGITAL, which approval may not be unreasonably
            withheld, and confidentiality restrictions and restrictions on use
            of the LICENSED SOFTWARE at least as restrictive as those contained
            in this Agreement. Except for above, SIMPLEX shall have no right to
            distribute the source code of the LICENSED SOFTWARE to any third
            parties.

   2.3. SIMPLEX hereby grants to DIGITAL for its internal purposes only, a fully
        paid, irrevocable, non-exclusive, perpetual, license to use within
        Digital Semiconductor business unit worldwide, under SIMPLEX's
        INTELLECTUAL PROPERTY RIGHTS including patent, copyright, mask work and
        trade secret rights, no more than [*] copies of Simplex's [*] software
        products in executable code form and including documentation. For
        purposes of clarification, DIGITAL may request up to [*] copies of any
        combination of [*]. Each copy may be used only on a single
        workstation/CPU. For SIMPLEX SOFTWARE upgrades which included DIGITAL's
        LICENSED SOFTWARE [*], Digital will receive such upgrades at no charge
        for a period of [*] years from the effective date of this agreement. For
        SIMPLEX SOFTWARE upgrades that do not include DIGITAL's LICENSED
        SOFTWARE [*], Digital xxxxxxxxxxxx at SIMPLEX's prevailing prices. For
        the purposes of this subsection, an "upgrade" is an optional module that
        may be added to a base software product to provide additional
        functionality or performance. Digital will receive maintenance/support
        for the SIMPLEX SOFTWARE through a single DIGITAL support coordinator at
        DIGITAL's Hudson facility for a period of [*] years from the effective
        date of this agreement at no additional charge.

        2.3.1. It is understood by the parties that the license grant to DIGITAL
               under this Article 2.3 shall permit DIGITAL to design, distribute
               and use the SIMPLEX SOFTWARE internally. But, unless otherwise
               agreed by the parties in writing, DIGITAL shall have no right to
               distribute, sublicense or grant access to the SIMPLEX SOFTWARE to
               any third party.

   2.4. DIGITAL and SIMPLEX agree that Articles 2.1 and 2.3 shall survive the
        termination of this Agreement for any reason whatsoever including
        expiration of TERM.

3. ARTICLE 3 - FEES AND ROYALTIES

   3.1. In consideration for DIGITAL's performance under this Agreement, and the
        rights and licenses granted to SIMPLEX under this Agreement, SIMPLEX
        shall grant Digital the licenses defined in Section 2.3 above. SIMPLEX
        [*] any royalty payments.

   3.2. Within four weeks of the execution of this Agreement, DIGITAL shall
        deliver to SIMPLEX one DIGITAL Alpha workstation and related software
        configured as previously specified by SIMPLEX which may be used by
        SIMPLEX for developmental purposes. Such workstation and software shall
        be subject to a separate AGREEMENT FOR LOAN OF PRODUCTS between the
        parties.

4. ARTICLE 4 - CONFIDENTIALITY

   4.1. As used in this Agreement, the term "CONFIDENTIAL INFORMATION" shall
        mean any information disclosed by one party to the other pursuant to
        this Agreement which is in written, graphic, machine readable or other
        tangible form and is marked with the identity of the disclosing party
        and "Confidential", "Proprietary" or in some other manner to indicate
        its confidential nature. CONFIDENTIAL INFORMATION may also include oral
        information disclosed by one party to the other pursuant to this
        Agreement, provided that such information is designated as confidential
        at the time of disclosure and reduced to a written summary by the
        disclosing party, within thirty (30) days after its oral disclosure,
        which is marked in a manner indicated above in Section 4.1 and delivered
        to the receiving party. Notwithstanding any failure to so identify it,
        however, the source

*Certain information on this page has been omitted and filed separately with
 the Commission. Confidential treatment has been requested with respect to the
 omitted portions.
<PAGE>   6

        code for the LICENSED SOFTWARE and the SIMPLEX SOFTWARE shall be deemed
        to be "CONFIDENTIAL INFORMATION" hereunder.

4.2.    Each party shall treat as confidential all CONFIDENTIAL INFORMATION of
        the other party, shall not use such CONFIDENTIAL INFORMATION except as
        expressly set forth herein or otherwise authorized in writing, shall
        implement reasonable procedures to prohibit the disclosure, unauthorized
        duplication, misuse or removal of the other party's CONFIDENTIAL
        INFORMATION and shall not disclose such CONFIDENTIAL INFORMATION to any
        third party except as may be necessary and required in connection with
        the rights and obligations of such party under this Agreement, and
        subject to confidentiality obligations at least as protective as those
        set forth herein. Without limiting the foregoing each of the parties
        shall use at least the same procedures and degree of care which it uses
        to prevent the disclosure of its own CONFIDENTIAL INFORMATION of like
        importance to prevent the disclosure of CONFIDENTIAL INFORMATION
        disclosed to it by the other party under this Agreement, but in no event
        less than reasonable care.

4.3.    The TERM of this Agreement, and for [*] years thereafter SIMPLEX shall
        maintain in confidence and not use except as expressly authorized
        herein, all LICENSED SOFTWARE and derivative works thereof made by
        SIMPLEX that either directly or indirectly discloses LICENSED SOFTWARE.
        ALL LICENSED SOFTWARE shall be referred to hereafter as "CONFIDENTIAL
        INFORMATION".

4.4.    SIMPLEX agrees that the confidentiality of the LICENSED SOFTWARE is an
        integral part of the ascribed value of the LICENSED SOFTWARE.

4.5.    CONFIDENTIAL INFORMATION shall not include and SIMPLEX shall not be
        required to protect in confidence any information disclosed to SIMPLEX
        under this Agreement which;

        4.5.1.   was in the receiving party's possession or was know to the
                 receiving party prior to receipt under this Agreement, as
                 evidenced by a signed and dated document created in the normal
                 course of business or other equally probative evidence;

        4.5.2.   is or becomes public knowledge without breach of this Agreement
                 by the receiving party as evidenced by a printed publication or
                 other equally probative evidence;

        4.5.3.   is or becomes available to the receiving party from a source
                 other than the disclosing party without a confidentiality
                 restriction and without a breach of this Agreement; or

        4.5.4.   is developed by the receiving party independent of and without
                 reference to CONFIDENTIAL INFORMATION received under this
                 Agreement.

        4.5.5.   is disclosed with the prior written approval of the disclosing
                 party;

        4.5.6.   is disclosed pursuant to the order or requirement of a court,
                 administrative agency, or other governmental body; provided,
                 that the receiving party shall provide prompt, advanced notice
                 thereof to enable the disclosing party to seek a protective
                 order or otherwise prevent such disclosure.

4.6.    Each party acknowledges that disclosure or use of any CONFIDENTIAL
        INFORMATION by the other party in a manner inconsistent with this
        Agreement will cause the other party irreparable injury which may not be
        adequately compensated by damages. Accordingly, in addition to all other
        remedies that a disclosing party shall have under this Agreement, the
        disclosing party shall have the right to equitable and injunctive relief
        to prevent the unauthorized use or disclosure of CONFIDENTIAL
        INFORMATION, and shall have the right to such damages (including without
        limitation court costs, and reasonable attorney fees awarded by a court
        of final resort and competent jurisdiction) as are occasioned by such
        unauthorized use or disclosure.

*Certain information on this page has been omitted and filed separately with
 the Commission. Confidential treatment has been requested with respect to the
 omitted portions.

                                                                               4

<PAGE>   7

     4.7.  Neither party shall disclose any confidential third party information
           to the other under this Agreement.

5.   ARTICLE 5 -- UPDATES, TRAINING AND SUPPORT SERVICES

     5.1.  DIGITAL agrees that it shall provide SIMPLEX all error corrections,
           updates, and upgrades to the LICENSED SOFTWARE which DIGITAL may, at
           its discretion, develop and make available internally from time to
           time, as to which DIGITAL shall own all rights, title, and interest.
           It is understood by the parties that such product updates are not on
           a scheduled or planned basis and entail no obligation by DIGITAL to
           actually produce any such updates or upgrades to SIMPLEX.

     5.2.  DIGITAL shall provide SIMPLEX Two person (2) week of training (not
           including time spent prior to execution hereof). Time spent via phone
           communication shall count towards the 2 person/week equivalent.
           DIGITAL, may at its discretion, provide training or support at
           another site: if training/support is not at the Hudson facility, the
           hours spend shall be calculated at double the time (i.e., 2 hours at
           other site = 1 hour at Hudson, MA) and all travel and lodging
           expenses for any DIGITAL personnel involved in such other site
           training will be paid by SIMPLEX. If additional training or support
           is required, DIGITAL may, at its discretion, provide additional
           support for a fee of [*] per day per person plus expenses.

6.   ARTICLE 6 -- TECHNOLOGY TRANSFER

     6.1.  DIGITAL shall deliver to SIMPLEX one complete copy of the LICENSED
           SOFTWARE within 2 weeks of the EFFECTIVE DATE of this Agreement.

     6.2.  If the event this Agreement is terminated in accordance with the
           terms of Article 7, SIMPLEX shall return to DIGITAL all whole or
           partial copies of LICENSED SOFTWARE which are in SIMPLEX's
           possession or control, whether direct or indirect.

7.   ARTICLE 7 -- WARRANTY PROVISIONS

     7.1.  THE LICENSED SOFTWARE AND THE SIMPLEX SOFTWARE ARE PROVIDED "AS IS"
           UNDER THIS AGREEMENT. NEITHER PARTY MAKES ANY WARRANTIES UNDER THIS
           AGREEMENT, WHETHER EXPRESS OR IMPLIED, AND SPECIFICALLY DISCLAIMS
           ANY IMPLIED WARRANTY OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
           PURPOSE. THE LICENSED SOFTWARE IS DEVELOPED FOR INTERNAL USE, AND IS
           NOT A DIGITAL LIST PRICE COMMERCIAL PRODUCT WHICH HAS BEEN SUBJECTED
           TO DIGITAL'S FULL COMMERCIAL QUALITY CONTROL AND PRODUCT VALIDATION
           PROCESSES. THE LICENSED SOFTWARE THUS MAY CONTAIN DEFECTS WHICH
           DIGITAL HAS NO OBLIGATION TO REMEDY.

     7.2.  To the best of DIGITAL's knowledge without conducting product
           clearance analyses or searches in the public records of the patent,
           copyright, and trademark offices throughout the world, DIGITAL has
           the right to use and to license the use of the LICENSED SOFTWARE in
           accordance with the terms and conditions of this Agreement.

     7.3.  The names used to identify each tool are for reference only. These
           names have been used internal to DIGITAL Only. These names are not
           to be confused with any external commercial product by the same name
           and may not be available for public use. SIMPLEX shall adopt its own
           unique and distinct names for each such CAD tool which it licenses
           to its customers and shall be solely responsible for clearance of
           the use of such names as trademarks/service marks for any SIMPLEX
           SOFTWARE and for defending and selling or otherwise satisfying any
           claim for infringement of any trademark or service rights anywhere
           in the world regarding the use by SIMPLEX of any such name.

     7.4.  THE WARRANTIES SET FORTH IN THIS ARTICLE 7 ARE IN LIEU OF ALL OTHER
           WARRANTIES, EXPRESS OR IMPLIED, AND DIGITAL EXPRESSLY DISCLAIMS ANY
           IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
           PURPOSE.

*Certain information on this page has been omitted and filed separately with
 the Commission. Confidential treatment has been requested with respect to the
 omitted portions.

                                                                               5
<PAGE>   8
8.      ARTICLE 8 - LIMITATION OF LIABILITY

        8.1.    IN NO EVENT SHALL EITHER PARTY BE LIABLE FOR SPECIAL,
                INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS OR
                LOSS OF USE, OR OTHER ECONOMIC LOSS OF ANY SORT. EXCEPT AS
                PROVIDED UNDER SECTION 9.3 BELOW, DIGITAL SHALL NOT BE LIABLE TO
                SIMPLEX, AND DISCLAIMS ALL LIABILITY TO ANY OTHER PERSON OR
                ENTITY IN CONNECTION WITH THIS AGREEMENT, FOR THE USE OR
                PERFORMANCE OF THE LICENSED SOFTWARE, INCLUDING WITHOUT
                LIMITATION ANY LIABILITY FOR NEGLIGENCE IN TORT. SIMPLEX SHALL
                NOT BE LIABLE TO DIGITAL, AND DISCLAIMS ALL LIABILITY TO ANY
                OTHER PERSON OR ENTITY IN CONNECTION WITH THIS AGREEMENT, FOR
                THE USE OR PERFORMANCE OF THE SIMPLEX SOFTWARE INCLUDING,
                WITHOUT LIMITATION, ANY LIABILITY FOR NEGLIGENCE IN TORT.

9.      ARTICLE 9 - REMEDIES

        9.1.    In the event a third party asserts a claim of intellectual
                property infringement, DIGITAL has no obligations to obtain
                rights to continue the use of any such LICENSED SOFTWARE which
                is the subject of such claim.

        9.2.    DIGITAL agrees, at its own expense, to defend or at its option
                to settle, any claim or action brought against SIMPLEX on the
                issue of infringement of any copyright or trade secret right of
                any third party by the LICENSED SOFTWARE as used or distributed
                within the scope of the licenses granted under this Agreement
                and to indemnify SIMPLEX against all damages and costs,
                including legal fees, which may be incurred by SIMPLEX under any
                such claim or action; provided that SIMPLEX provides DIGITAL
                with (i) prompt written notice of such claim (ii) sole control
                and authority over the defense or settlement thereof, and (iii)
                proper and full information and assistance (at DIGITAL's
                expense, except for the cost of SIMPLEX's employee's time) to
                settle and/or defend any such claim or action.

        9.3.    Notwithstanding the provisions of Section 9.2 above, DIGITAL
                assumes no liability for infringement claims which would not
                exist but for (i) the combination of any LICENSED SOFTWARE with
                other software not provided by DIGITAL, or (iii) the
                modification of the LICENSED SOFTWARE unless such modification
                was made by DIGITAL.

        9.4.    SIMPLEX agrees, at its own expense, to defend or at its option
                to settle, any claim or action brought against DIGITAL on the
                issue of infringement of any copyright or trade secret right of
                any third party by the SIMPLEX SOFTWARE as used or distributed
                within the scope of the licenses granted under this Agreement
                and to indemnify DIGITAL against all damages and costs,
                including legal fees, which may be incurred by DIGITAL under any
                such claim or action; provided that DIGITAL provides SIMPLEX
                with (i) prompt written notice of such claim (ii) sole control
                and authority over the defense or settlement thereof, and (iii)
                proper and full information and assistance (at SIMPLEX's
                expense, except for the cost of DIGITAL's employee's time) to
                settle and/or defend any such claim or action.

                9.4.1.  Notwithstanding the provisions of Section 9.4 above,
                        SIMPLEX assumes no liability for infringement claims
                        which would not exist but for (i) the combination of
                        any SIMPLEX SOFTWARE with other software not provided
                        by SIMPLEX, or (iii) the modification of the SIMPLEX
                        SOFTWARE unless such modification was made by SIMPLEX.

        9.5     THE REMEDIES SET FORTH IN THIS ARTICLE 9 CONSTITUTES EACH
                PARTY'S EXCLUSIVE REMEDIES FOR INTELLECTUAL PROPERTY
                INFRINGEMENT, AND DEFECTS (WHETHER PATENT OR LATENT) IN THE
                LICENSED SOFTWARE OR SIMPLEX SOFTWARE AS APPLICABLE.

10.     ARTICLE 10 - INJUNCTIVE RELIEF

        10.1.   The parties hereby declare that the respective rights of the
                parties under Sections 2 or Section 4 are of a unique nature,
                the loss of which may cause

                                                                               6

<PAGE>   9
            irreparable harm, and that it may be impossible to measure in money
            the damages which will accrue to a party hereto by reason of the
            loss of such rights. Accordingly, in the event of any breach or
            threatened breach of Sections 2 or Section 4, the party whose
            software or CONFIDENTIAL INFORMATION are the subject of such breach
            or threatened breach shall be entitled to a final order from a court
            of competent jurisdiction of injunctive and other equitable relief,
            and if any party hereto shall institute any action or proceeding to
            enforce by specific performance or other equitable relief the
            provisions hereof, any the party against whom such action or
            proceeding in brought hereby waives the claim or defense therein
            that such party has an adequate remedy at law, and such part shall
            not urge in any such action or proceeding the claim or defense that
            such remedy at law exists. This Section 10 shall not limit or
            constrain the right of a party to pursue and recover damages at law
            for breaches of this Agreement, including breaches of Section 2 or
            Section 4.

11.  ARTICLE 11 - TERMINATION

     11.1.   If either party hereto shall fail to perform or observe any of the
             terms and conditions to be performed or observed by it under this
             Agreement, the other party shall give written notice to the
             defaulting party specifying the respects in which the defaulting
             party has failed to perform or observe the terms and conditions of
             this Agreement, and in the event that any default so indicated is
             not remedied by the defaulting party within thirty (30) days after
             receipt of such notice, the party not in default may in its sole
             discretion thereafter elect to terminate this Agreement, and,
             except as otherwise provided herein to survive termination, this
             Agreement and all the future obligations owed and future rights
             granted herein to the defaulting party shall immediately terminate.

             11.1.1.  As used in this Agreement the term "breach" or "default"
                      by a party shall mean a failure to perform or observe a
                      material term or provision hereof which remains uncurled
                      after the notice and time period set forth above. The
                      following events may constitute the breach of material
                      term of this Agreement.

                      11.1.1.1. a knowing and material violation of the
                                restrictions on license rights set forth herein.

                      11.1.1.2. failure by a party to follow proper procedures
                                for safeguarding CONFIDENTIAL INFORMATION under
                                this Agreement;

                      11.1.1.3. failure by SIMPLEX to make payment when due;

                      11.1.1.4. breach of warranty of either SIMPLEX or DIGITAL
                                and

                      11.1.1.5. failure of DIGITAL to provide training and
                                support services pursuant to Article 5 above.

      11.2.  On or before thirty (30) days prior to the expiration of the TERM
             of this Agreement, the parties may meet in person or by phone to
             determine whether and under what conditions this Agreement may be
             renewed.

      11.3.  The parties hereto agree that the termination of this Agreement
             shall not release either party from any other liability which shall
             have accrued to the other party at the time such termination
             becomes effective (provided that a remedy for such liability has
             not been expressly provided in this Agreement), nor affect in any
             manner the survival of any right, duty or obligation of either
             party which is expressly stated elsewhere in this Agreement to
             survive termination.

      11.4.  In the event of any termination of this Agreement for any reason,
             SIMPLEX shall no longer be entitled to continue to receive error
             corrections, updates and upgrades pursuant to section 5.1. However
             its rights to the LICENSED SOFTWARE existing as of the termination
             date shall continue.

12.  ARTICLE 12 - NOTICES

      12.1.  Any notice required or permitted to be given under this Agreement
             shall be sufficient as of three (3) days following the date of
             mailing if given by prepaid, first class, registered or certified
             mail addressed to the respective address, subject to change upon
             written notice, of the other Party as follows:

                                                                               7
<PAGE>   10
                    If DIGITAL:
                            John McClean
                            Acquisition Consultant
                            Digital Equipment Corporation
                            77 Reed Road
                            Hudson, MA 01749-2895
                    Copy to:
                            Digital Semiconductor General Counsel
                            Digital Equipment Corporation
                            111 Powdermill Road, MSO2-3
                            Maynard, MA 01754
                    If to LICENSEE:
                            Resve Saleh
                            President
                            Simplex Solutions, Inc.
                            2540 North First Street, Suite 302
                            San Jose, CA 95131
13.  ARTICLE 13 - GENERAL TERMS
     13.1. Waiver/Amendment: No waiver, amendment, or modification of any
           provision of this Agreement shall be effective unless in writing and
           signed by the party against whom such waiver, amendment or
           modification is sought to be enforced.
     13.2. Assignment or Transfer: Except as otherwise stated herein, SIMPLEX
           may not assign or transfer in any manner, including by operation of
           law, any of its rights or obligations under this Agreement to any
           third party integrated circuit manufacturer (including, but not
           limited to, Intel or National Semiconductor, etc.) without the
           express written consent of DIGITAL. Any assignment or transfer made
           without such consent shall be void.
     13.3. The recipient of DIGITAL technical information agrees not to
           export/re-export this technical information or any direct/immediate
           product of the technical information to any country proscribed under
           the U.S. Export Administrating Regulations, Parts 700 and 779.4
           (Country Groups Q, S, W, Y, and Z and the People's Republic of China
           and Afghanistan) without first receiving authorization from the U.S.
           Department of Commerce.
     13.4. Choice Of Law And Forum: The rights of the parties hereunder shall be
           governed by the laws of the State of California, U.S.A. Any
           litigation between the parties shall be commenced and prosecuted in
           California.
     13.5. Severability: If any provision of this Agreement shall be held by a
           court of competent jurisdiction to be contrary to law, the remaining
           provisions of this Agreement shall remain in full force and effect,
           and shall be interpreted to effect the intentions of the parties
           interpretations as if such provision has never been in this
           Agreement.
     13.6. Publicity:
           13.6.1. Each party shall use its reasonable and diligent efforts not
                   to disclose to any third party the terms and conditions of
                   this Agreement during its TERM, except as required by law, or
                   by governmental regulation, requirement or order, or as may
                   be necessary to establish or assert its rights hereunder, or
                   pursuant to confidentiality obligations, to bankers and other
                   financing sources and to auditors, attorneys and other
                   experts as deemed necessary by SIMPLEX to obtain financing.
           13.6.2. Notwithstanding the proscriptions of Article 13.6.1 above,
                   DIGITAL and SIMPLEX shall cooperate in preparing a press
                   release and a public announcement of the occurrence of this
                   Agreement, each of which shall occur within thirty (30) days
                   following the execution of this Agreement.
           13.6.3. DIGITAL shall have the right to review any subsequent press
                   releases or other promotional advertising or materials of
                   SIMPLEX that refer to DIGITAL, which shall be provided to
                   DIGITAL thirty (30) days in advance

                                                                               8
<PAGE>   11
             of release. If such releases, advertising or materials is found
             unacceptable by DIGITAL, SIMPLEX will revise the same in accordance
             with DIGITAL's wishes. DIGITAL shall review any such releases,
             plans or materials within 21 days and give written notice to
             SIMPLEX of approval or disapproval. DIGITAL's review team shall
             consist of at least one representative from the DIGITAL. SIMPLEX
             understands and agrees that the guidelines which DIGITAL shall use
             will be the absence from any such press release or other
             promotional material of any mention that any LICENSED SOFTWARE
             received from DIGITAL has been used, or is currently being used, by
             DIGITAL to design any specific semiconductor device, including by
             way of example only, DIGITAL's DECchip 21064 and subsequent chips
             utilizing the "ALPHA" architecture, and including any names used
             formally or informally by DIGITAL or in the industry or industry
             press, such as "ALPHA chips" or "ALPHA microprocessors" or the
             like. Once DIGITAL has found a particular press release, or piece
             of advertising or promotional material to be accepted, further
             publication approval by DIGITAL shall not be required for such
             release or piece of material.

     13.6.4. Notwithstanding the foregoing, SIMPLEX, without the approval of
             DIGITAL, shall have the right to indicate to the public that
             SIMPLEX has licensed the LICENSED SOFTWARE from DIGITAL, by using
             the notice "portions of this product incorporated technology
             licensed from DIGITAL EQUIPMENT CORPORATION", or the substantial
             equivalent thereof.

13.7. No prior condemnation, waiver, overlooking or lack of notice of any act
      or event giving rise to a right by either party to terminate shall operate
      to restrict, limit, or otherwise affect a subsequent right to either party
      to terminate this Agreement because of any act or event of a same or
      different nature.

13.8. Entire Agreement: This Agreement constitutes the complete and entire
      agreement between the parties with respect to the subject matter addressed
      herein, and merges all prior proposals and negotiations, whether oral or
      written, and all other prior communications and agreements between the
      parties with respect to such matter.

IN WITNESS WHEREOF, the parties hereto have as of the effective date first above
written caused this Agreement, including Appendix A which hereby is incorporated
by reference, to be signed in duplicate by their duly authorized
representatives.

DIGITAL EQUIPMENT CORPORATION         SIMPLEX SOLUTIONS, INC.

/s/ Robert Ed Caldwell                /s/ Resve Saleh
----------------------------          ----------------------------

Name: Robert Ed Caldwell              Name: Resve Saleh

Title: Vice President                 Title: President
       Digital Semiconductor

Date: 9/22/95                         Date: 9/25/95
<PAGE>   12
                APPENDIX A -- LICENSED SOFTWARE & DOCUMENTATION

The following are the CAD tools referenced in this agreement.

All these tools are purchased on the basis "as is". DIGITAL does not have any
obligation to add or change anything. It is a free will of DIGITAL
SEMICONDUCTOR / SEG / CAD group to release updates when and if they are
available. The Source Code will be supplied for all the software listed below.

[*]

*Certain information on this page has been omitted and filed separately with
 the Commission. Confidential treatment has been requested with respect to the
 omitted portions.
<PAGE>   13

6.   Library Utilities

[*]

The following are the supporting documentation for the above tools:

[*]

*Certain information on this page has been omitted and filed separately with
 the Commission. Confidential treatment has been requested with respect to the
 omitted portions.

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00020-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00020-of-00352.parquet"}]]