CITRIX SYSTEMS INC
8-K, 1997-06-20
PREPACKAGED SOFTWARE
Previous: SPARTAN STORES INC, 424B3, 1997-06-20
Next: SHOPKO STORES INC, 8-K, 1997-06-20



<PAGE>
 
                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549


                                   __________

                                    FORM 8-K

                                 CURRENT REPORT

                     PURSUANT TO SECTION 13 OR 15(D) OF THE
                        SECURITIES EXCHANGE ACT OF 1934


                                 Date of Report
                (Date of earliest event reported):  May 9, 1997



                             Citrix Systems, Inc.
                 ---------------------------------------------
             (Exact name of Registrant as specified in its charter)


 
           Delaware                       0-27084            75-2275152
- -------------------------------         ------------     -------------------
(State or other jurisdiction of         (Commission        (IRS Employer
       Incorporation)                   File number)     Identification No.)
 
 
 
           6400 N.W. 6th Way
        Fort Lauderdale, Florida                              33309
- ----------------------------------------                   -----------
(Address of principal executive offices)                    (Zip Code)


      Registrant's telephone number, including area code:  (954) 267-3000

<PAGE>
 
                                      -2-

Item 5.   Other Events.
          -------------

     On May 9, 1997, Citrix Systems, Inc., a Delaware corporation (the
"Company"), and Microsoft Corporation, a Washington corporation ("Microsoft"),
entered into a License, Development and Marketing Agreement (the "Development
Agreement") which provides for the licensing to Microsoft of certain of the
Company's multi-user software enhancements to Microsoft's Windows NT Server and
for the cooperation between the parties for the development of future multi-user
versions of Microsoft Windows NT Server, code-named Hydrix 4.x and Hydrix 5.x.
The agreement also provides for each party to develop its own enhancements or
"plug-ins" to the jointly developed products which may provide access to the
Hydrix base platform from a wide variety of computing devices, such as a Company
developed plug-in that implements the ICA protocol on the new platform.

     On May 30, 1997, pursuant to the terms of the Development Agreement, the
Company received an aggregate of $75,000,000 as a non-refundable royalty payment
and for engineering and support services to be rendered by the Company.  Under
the terms of the Development Agreement, the Company will be eligible to receive
royalty payments of up to an additional $100,000,000 based on Microsoft's
release and shipment of Hydrix 4.x and Hydrix 5.x products.  In addition,
Microsoft and the Company have agreed to engage in certain joint marketing
efforts to promote use of Windows NT Server-based multi-user software and the
Company's ICA/(R)/ protocol.  Additionally, for a period of at least two and
one-half years, Microsoft has agreed to endorse only the Company's ICA protocol
as the preferred way to provide multi-user Windows access for devices other than
Windows client devices.  Further, subject to the terms of the Agreement, the
Company shall be entitled to license versions of its WinFrame technology based
on Windows NT v.3.51 until at least September 30, 2001.

     The Company's relationship with Microsoft is subject to certain risks and
uncertainties.  First, the Hydrix-based platforms will allow Microsoft to create
plug-in products that could become competitive with at least some of the
Company's current WinFrame products and future Hydrix-related plug-in product
offerings.  Second, as stated above, Microsoft has agreed to endorse only the
Company's ICA protocol as the preferred method to provide multi-user Windows
access for devices other than Windows clients for a period of two and one-half
years.  After the two and one-half year period expires, it is possible that
Microsoft will market or endorse other methods to provide non-Windows client
devices multi-user Windows access.  Finally, the Company's royalties pursuant to
the Development Agreement rely significantly on Microsoft's ability to market
the Hydrix 4.x and 5.x products.  Microsoft's distributors and resellers are not
within the control of the Company and, to the Company's knowledge, are not
obligated to purchase products from Microsoft.  If Microsoft (1) develops
competitive plug-in products, (2) endorses in the future other methods to
provide non-Windows client devices multi-user Windows access or (3) is unable to
successfully market the Hydrix-based products, the Company's business, results
of operations and financial condition could be adversely affected.

     In addition to the factors outlined in the preceding paragraph, there are
other risks and uncertainties pertaining to the Company's relationship with
Microsoft that appear in "Management's Discussion and Analysis of Financial
Condition and Results of Operations -- 

<PAGE>
                                     -3-

 
Certain Factors Which May Affect Future Results" included in the Company's
Quarterly Report on Form 10-Q for the quarter ended March 31, 1997, which are
hereby incorporated by reference.

Item 7.   Financial Statements, Pro Forma Financial Information and Exhibits.
          -------------------------------------------------------------------

          (c)  Exhibits.
               -------- 
<TABLE> 
<CAPTION> 

 
Exhibit No.         Description
- -----------         -----------
<S>                 <C>         
10*                 License, Development and Marketing Agreement dated as of May
                    9, 1997 by and between Citrix Systems, Inc. and Microsoft
                    Corporation.

99                  Press release of the Company dated May 12, 1997.

</TABLE> 

             *Confidential treatment requested as to omitted portions pursuant
              to Rule 24b-2 promulgated under the Securities Exchange Act of
              1934, as amended.

<PAGE>
 
                                     - 4 -

                                   SIGNATURES


     Pursuant to the requirements of the Securities Exchange Act of 1934, the
Company has duly caused this report to be signed on its behalf by the
undersigned authorized officer.


                                    CITRIX SYSTEMS, INC.



June 20, 1997
                                     By:/s/ James J. Felcyn Jr.
                                        -----------------------
                                        James J. Felcyn, Jr.
                                        Vice President - Finance and 
                                        Administration, Chief Financial 
                                        Officer, Treasurer and Assistant 
                                        Secretary

<PAGE>
 
                                 EXHIBIT INDEX
                                 -------------

<TABLE>
<CAPTION>
 
 
                                                          Page Number in
                                                          Sequentially 
Exhibit No.                  Description                  Numbered Copy
- -----------                  -----------                  -------------
 
<S>              <C>                        
10*              License, Development and Marketing 
                 Agreement dated as of May 9, 1997 
                 by and between Citrix Systems, Inc. 
                 and Microsoft Corporation.

99               Press release of the Company dated 
                 May 12, 1997.
 
 
 
</TABLE>



         *Confidential treatment requested as to omitted portions pursuant to
          Rule 24b-2 promulgated under the Securities Exchange Act of 1934, as
          amended.

<PAGE>
 
                                                                Exhibit 10

                  LICENSE, DEVELOPMENT AND MARKETING AGREEMENT


This LICENSE, DEVELOPMENT AND MARKETING AGREEMENT (the "Agreement") is entered
into and effective as of May 9, 1997 (the "Effective Date"), by and between
MICROSOFT CORPORATION, a Washington corporation (hereinafter "Microsoft"), and
CITRIX SYSTEMS, INC., a Delaware Corporation (hereinafter "Citrix").

                                    RECITALS

A.   Microsoft and Citrix desire to work together as provided in this Agreement
     to develop multi-user functionality for Microsoft's Windows NT Server
     operating system which will be owned and marketed by Microsoft;

B.   Microsoft desires to license from Citrix a subset of Citrix' existing
     multi-user software enhancements to Microsoft's Windows NT Server, as
     provided in this Agreement;

C.   Microsoft desires to cooperate with Citrix as provided in this Agreement in
     the development of plug-ins and other complementary product offerings; and

D.   Microsoft and Citrix desire to engage in joint marketing to promote use of
     Windows NT Server-based multi-user software and Citrix' ICA, as provided in
     this Agreement.

                                   AGREEMENT

1    Definitions

     1.1  "Citrix Deliverables" shall mean the information and materials
          described in Exhibit A.

     1.2  "Clone Product" shall mean either party's product designed, developed
          or acquired after the Effective Date that competes with and is a fully
          compatible look-alike or act-alike (by providing the same or
          substantially the same user interface and/or APIs) version of an
          Established Product of the other Party.  An Established Product is a
          product publicly released or released for significant public beta
          testing, and designed, developed, or acquired before the introduction
          of the party's product; Clone Product shall exclude software, such as
          drivers, network protocols, etc., where such similarity with the user
          interface or APIs is dictated by adherence to an industry standard
          which was widely recognized prior to the release of a party's product.
          A party's product shall not be deemed to be a Clone Product solely on
          the basis that it provides the same or substantially the same
          functionality as a product of the other Party.  For the purposes of
          this definition, neither the ICA protocol nor Microsoft created
          interfaces and protocols 
<PAGE>
 
                                      -2-



          [CONFIDENTIAL TREATMENT REQUESTED]/*/ shall be deemed to be
          [CONFIDENTIAL TREATMENT REQUESTED]/*/ . "Microsoft Windows Operating
          System Products" shall mean Windows (and successors and derivatives),
          Windows NT (and successors and derivatives), and Windows CE (and
          successors and derivatives). The parties have utilized a definition of
          "Clone Product" in Exhibit F which is different from the foregoing.
          The definition in this Section shall apply to all of the provisions of
          this Agreement other than Exhibit F.

    1.3   "Hydrix" shall mean a Microsoft product offering or offerings based
          upon or working in conjunction with Windows NT Server, which offering
          or offerings provide Multi-User functionality (as defined below).
          "Hydrix 4.0 and Hydrix 4.x" shall mean such product offerings which
          are based on Windows NT Server versions 4.0 and 4.x, respectively, as
          further described in Exhibit C, and "Hydrix 5.0 and Hydrix 5.x" shall
          mean such product offerings which are based on Windows NT Server
          versions 5.0 and 5.x, respectively, as further described in Exhibit D.

    1.4   "Hydrix Plug-In Interface" shall mean the unique Hydrix Multi-User
          subsystem plug-in interfaces developed by the parties hereunder as
          further described in Exhibits C and D.

    1.5   "ICA" shall mean Citrix' protocol currently known as Intelligent
          Console Architecture.

    1.6   "ICA Version of Internet Explorer" shall mean versions of Internet
          Explorer, which are created in accordance with Section 4.3.1.

    1.7   "Internet Explorer" shall mean versions 3.x and 4.x of the Microsoft
          standalone web browser which is marketed under the name "Internet
          Explorer."

    1.8   "Invention" shall mean any idea, design, concept, technique,
          invention, discovery or improvement, whether or not patentable.

    1.9   "Key System" shall mean a system or mechanism enabling Hydrix servers
          to manage access by and identify the type of clients which access such
          servers.

    1.10  "Key System Client Software" shall mean a client software component
          that is to be included in Hydrix-based client programs to implement
          the Key System released by Microsoft to Citrix during the term of this
          Agreement.  The purpose of this component is to ensure the proper
          validation of Hydrix access.  If the Key 

- ----------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
    AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED
    MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2
    PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                      -3-

          System Client Software includes functionality beyond client type and
          unique identifiers, ICA-based devices need not support this additional
          functionality.

     1.11 "Marketing Liaisons" shall mean the representatives of the parties
          who are so identified pursuant to Section 7.

     1.12 "Microsoft Deliverables" shall mean the information and materials
          described in Exhibit B.

     1.13 "Multi-User" shall mean a system in which a single server computer is
          connected to one or more computer terminals (or personal computers
          emulating terminals) which terminals only display the output of, and
          gather input for, the applications running on the server computer.  A
          Multi-User configuration is distinguished from a networked
          configuration in that the controlling application programs for the
          users at terminals in a Multi-User configuration execute only on the
          server and not on the computer terminals.  The parties have utilized a
          definition of "Multi-User" in Exhibit F which is different from the
          foregoing.  The definition in this Section shall apply to all of the
          provisions of this Agreement other than Exhibit F.

     1.14 "Object Code" shall mean machine-executable computer software code in
          binary form.

     1.15 "Named Executives" shall mean the representatives of the parties who
          are so identified pursuant to Section 7.

     1.16 "Net Receipts" shall mean royalties, fees and other amounts received
          by Microsoft from the shipment, licensing, and other distribution of a
          product, less reasonable adjustments for returns, rebates, freight
          charges, and sales, use, value-added, and other applicable taxes,
          provided that any returns or rebates are computed in accordance with
          the last two sentences of Section 9.1.2.5 hereof.

     1.17 "Plug-In Software" shall mean Windows NT Server-based server side
          software, developed by Citrix or Microsoft that (i) implements Citrix
          or Microsoft protocols, (ii) allows a remote client to execute
          applications on the server as described in Section 1.13, and (iii)
          utilizes the Hydrix Plug-In Interface.

     1.18 "Pure ICA Device" shall mean a device comprising hardware and
          software, whether now known or hereafter invented, that will
          communicate with application servers using only ICA presentation
          service protocols.  Pure ICA Devices may have local execution of
          applets that have been pre-installed or loaded by an administrator,
          but shall not contain applets downloaded by an end user or offer any
          other substantial functionality except via an ICA connection to an
          application server.  A device which meets the definition of a Pure ICA
          device but which can be rebooted to run an alternative software
          environment not meeting the definition of a Pure ICA Device shall
          still be considered a Pure ICA Device when running solely as a Pure
          ICA Device.

<PAGE>
 
                                      -4-

     1.19 "Source Code" shall mean commented program source code, header files,
          resource files, bitmaps, icons, and help file source code for the
          applicable software product.

     1.20 "Technical Coordinators" shall mean the representatives of the
          parties who are so identified pursuant to Section 7.

     1.21 "Windows CE" shall mean the current Windows CE product offered by
          Microsoft, or its equivalent and follow-on versions and derivative
          works thereof.

     1.22 "Windows Client Devices" shall mean computers and other electronic
          devices, whether now known or hereafter developed, which use any
          Microsoft Windows family operating system now known or hereafter
          developed, including without limitation Microsoft Windows 3.x (whether
          running alone or in conjunction with any other operating system (such
          as MS-DOS or OS/2)), and derivatives and successors, Microsoft Windows
          95 and derivatives and successors, Windows CE and derivatives and
          successors, Windows NT Workstation and derivatives and successors, and
          Windows NT Server and derivatives and successors. In no event,
          however, shall "Windows Client Devices" include any computer or other
          electronic device which uses an MS-DOS branded operating system
          product or an OS/2 branded operating system product as its only
          operating system.

     1.23 "WinFrame" shall mean any version of the Citrix product currently
          offered under the name "WinFrame."  "WinFrame 2.0/3.51" shall mean any
          WinFrame product which (i) is based on Windows NT Server v. 3.51 code;
          and (ii) corresponds with the specifications existing as of the
          Effective Date for WinFrame 2.0/4.0, but which is ported back to
          Windows NT Server v.3.51, including any limitations which are
          necessitated by such downgrade.  "WinFrame 2.0/4.0" shall mean a
          version of the WinFrame 2.0 product which is based on Windows NT
          Server v.4.0 as such version exists or has been described in Citrix'
          specifications as of the Effective Date.

2    Deliverables
     ------------

     2.1  Citrix.  Citrix shall deliver to Microsoft the Citrix Deliverables
          ------                                                            
          according to the schedule set forth in Exhibit A.

     2.2  Microsoft.  Microsoft shall deliver to Citrix the Microsoft
          ---------                                                  
          Deliverables according to the schedule set forth in Exhibit B.

3    Work Scope
     ----------

     3.1  Development of Hydrix.  Microsoft and Citrix will work together to
          ---------------------                                             
          develop Hydrix 4.x and Hydrix 5.x (including the joint development of
          Hydrix Plug-In Interfaces) in accordance with the architectural
          specifications and development plans which are further described in
          Exhibits C and D.  The parties agree that Hydrix is to be a superset
          of Windows NT Server, and will be made commercially available through
          Microsoft's standard distribution channels.  Both parties 

<PAGE>
 
                                      -5-

          recognize that a goal of this Agreement is to reconcile the interfaces
          for Citrix Plug-in Software and Microsoft Plug-in Software, but that
          this goal may not be achieved with respect to Hydrix 4.0.

          3.1.1  The Technical Coordinators (or their designees) are responsible
                 for all issues relating to staffing and assignments. Each party
                 shall pay its own employees' salaries and expenses.

          3.1.2  Microsoft shall provide office space and appropriate computer
                 equipment to Citrix employees located in Redmond performing
                 work hereunder. Microsoft will allow Citrix engineers to have
                 unescorted access to its Redmond facility as is reasonable for
                 the purpose of performing work hereunder. Citrix engineers
                 shall abide by all rules and regulations pertaining to work at
                 Microsoft's campus.

     3.2  Enhancements to Hydrix Plug-in Interface.  Microsoft and Citrix will
          ----------------------------------------                            
          jointly architect and develop enhancements to the Hydrix Plug-In
          Interface and system capabilities required to support the Hydrix Plug-
          In Interface.

     3.3  Procedure for Considering Enhancement Proposals by Either Party.  Each
          ---------------------------------------------------------------       
          party's development team may present proposals for possible
          enhancements to Hydrix and to the Hydrix Plug-In Interface to the
          development team of the other party.  In selecting and implementing
          any such enhancement, each party will use commercially reasonable good
          faith efforts to take into account the strategic goals, reliability
          requirements, and schedule constraints of the other.  Should a
          proposed enhancement be rejected by either development team the
          proposing party may elect to escalate such proposal to the Technical
          Coordinators and then the Named Executives; provided, however, that
          Microsoft shall retain final authority over the Hydrix architecture,
          including enhancements to the Hydrix Plug-In Interface.  In making
          such determinations, Microsoft agrees to evaluate possible
          enhancements to the Hydrix Plug-In Interface in light of the following
          mutual goals of the parties:  (i) not disadvantaging Citrix Plug-In
          Software vis-a-vis Microsoft Plug-In Software; (ii) ensuring that the
          performance and scalability of Hydrix following the proposed
          enhancement will not be materially worse than is provided by the
          current Hydrix product offering, or, for the first Hydrix release,
          than that provided by WinFrame 2.0/4.0; and (iii) ensuring that
          enhancements do not cause Citrix Plug-In Software to materially
          regress in terms of performance or functionality.  The parties agree
          that the foregoing goals may be overridden by Microsoft's need to
          address market demand for enhancements to Hydrix which cause a minor
          regression in the performance and functionality of Citrix Plug-In
          Software, and which regression it is technically impracticable to
          prevent within a commercially reasonable development schedule.  If
          after escalation, Microsoft rejects a proposed enhancement which
          Citrix considers essential, Microsoft will cooperate with Citrix to
          determine an alternative business and technical solution which will
          allow Citrix to develop and distribute such enhancement with its Plug-
          In 

<PAGE>
 
                                      -6-

          Software.  Neither party may charge any fee to the other party in
          connection with cooperative efforts undertaken pursuant to the
          foregoing sentence.

          3.3.1  Citrix shall have the option of maintaining a reasonable
                 technical liaison staff at Microsoft for the purpose of
                 participating in the architecture and implementation of
                 enhancements to the Hydrix Plug-In Interface.

     3.4  Support Documentation.  Citrix will provide Microsoft on an ongoing
          ---------------------                                              
          basis with current technical and support documentation concerning
          Citrix' Hydrix-related products, including but not limited to the
          Citrix Plug-In Software, in order to enable Microsoft technical
          support personnel to be able to identify errors or support issues
          which are related to the Citrix Plug-In Software.

     3.5  Support Responsibilities for Hydrix and Plug-In Software.  Microsoft
          --------------------------------------------------------            
          will provide initial end user support contacts and problem diagnosis
          for all versions of Hydrix.  Citrix will provide Microsoft with all
          technical assistance and code modifications necessary to resolve end
          user support requests from Hydrix 4.x end users which cannot be
          addressed by Microsoft support personnel through reference to standard
          product support materials.  In providing such Hydrix technical support
          to Microsoft, Citrix will comply with the response time requirements
          set forth in Exhibit G. Any code modifications generated as part of
          this effort shall be included in Hydrix service packs unless Microsoft
          elects otherwise on a case-by-case basis.  If Microsoft elects not to
          include any such modification in Hydrix service packs, Microsoft will
          make such modifications generally available through an alternative
          distribution mechanism.  Each party will provide all customer support
          for its respective Plug-In Software.  The parties will work in good
          faith to design an infrastructure for referral and escalation of
          Hydrix and Plug-In Software-related support requests, and amend
          Exhibit G as appropriate.

     3.6  Location of Work.  Except as provided above and except as mutually
          ----------------                                                  
          agreed by the Technical Coordinators, the parties agree that all work
          to be performed hereunder shall be performed at the facilities of the
          party performing such work.

     3.7  Marketing.  The parties will make the announcements and conduct the
          ---------                                                          
          joint marketing and promotions provided for in Exhibit E and as agreed
          upon by the Technical Coordinators or Named Executives from time to
          time.

     3.8  Quarterly Reviews.  Quarterly review meetings relating to the work to
          -----------------                                                    
          be performed hereunder will be held at either Microsoft or Citrix
          within a reasonable time after the end of each calendar quarter.  The
          purpose of these meetings is for the Named Executives or their
          designees to disclose relevant product strategies and plans to one
          another, as appropriate, and to encourage a periodic exchange of views
          by Microsoft and Citrix personnel having an interest in, and/or
          responsibility for, the progress of the work to be performed
          hereunder.

<PAGE>
 
                                      -7-

     3.9  Further Product Plans.  Microsoft agrees to consider, in good faith, a
          ---------------------                                                 
          plan for Microsoft to offer an entry-level Hydrix product that
          incorporates the Hydrix Plug-In Interface, targeted at small business
          and replicated sites with low-cost characteristics.

4    License Grants
     --------------

     4.1  Citrix Deliverables.  Citrix hereby grants to Microsoft, under Citrix'
          -------------------                                                   
          intellectual property rights (other than trademarks), the following
          worldwide, nonexclusive, [CONFIDENTIAL TREATMENT REQUESTED]/*/ rights:
          (i) to modify and create derivative works of the Citrix Deliverables
          in Source Code form; (ii) to make, use, copy, import, distribute
          (directly or indirectly), license, sell, offer to sell, rent or lease
          the Citrix Deliverables (and derivative works thereof created under
          clause (i) above) in Source and Object Code form; and (iii) to
          sublicense any and all of the rights set forth in clauses (i) and (ii)
          above to further third parties, including the right to sub-license
          such rights to further third parties.

     4.2  Key System Client Software.  Microsoft hereby grants to Citrix, under
          --------------------------                                           
          Microsoft's intellectual property rights (other than trademarks), the
          following world-wide, non-exclusive, [CONFIDENTIAL TREATMENT
          REQUESTED]/*/, solely for incorporation into devices accessing the
          Citrix Plug-In Software running on Windows NT Server:  (i) to make,
          use, copy, import, distribute (directly or indirectly), license, sell,
          offer to sell, rent or lease the Key System Client Software in Object
          Code form; (ii) to sub-license any and all of the foregoing rights to
          further third parties, including the right to sub-license such rights
          to further third parties, and (iii) to copy, modify, and create
          derivative works of the Key System Client Software in Source Code form
          for the sole purpose of porting such software to operating systems
          other than those used with Windows Client Devices, provided, however,
          that Citrix may not reduce the integrity of the Microsoft Key System
          authentication logic and Citrix distributes the Key System Software
          under terms and conditions which prohibit reverse engineering or any
          other means to circumvent security or use of the software in an
          unauthorized manner. Citrix has the right to use contractors or
          consultants who have been approved in writing by Microsoft to perform
          the porting described in paragraph (iii) above on Citrix' behalf,
          subject to the terms and conditions of this Agreement. Microsoft
          hereby agrees to consider in good faith any formal written Citrix
          request to [CONFIDENTIAL TREATMENT REQUESTED]/*/ in conjunction with
          distribution licenses to Citrix Plug-In Software or Citrix client
          software in order for [CONFIDENTIAL TREATMENT REQUESTED]/*/ as
          authorized therein, and make reasonable efforts to respond to such
          requests within 

- ----------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
    AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED
    MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2
    PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                      -8-

          [CONFIDENTIAL TREATMENT REQUESTED]/*/ days, and such
          approval shall not be unreasonably withheld. If Microsoft does not
          respond within these [CONFIDENTIAL TREATMENT REQUESTED]/*/ days, such
          approval shall be deemed granted.

     4.3  Internet Explorer.
          ----------------- 

          4.3.1  Microsoft hereby grants to Citrix, under Microsoft's
                 intellectual property rights (other than trademarks), a world-
                 wide, non-exclusive right during the term of this Agreement to
                 use, copy, modify, and create derivative works of Internet
                 Explorer in Source Code form for the sole purpose of improving
                 the performance of Internet Explorer as it relates to Hydrix
                 Plug-In Software, provided that such improvements do not change
                 the resulting version of Internet Explorer's external behavior
                 or end user interface.

          4.3.2  Citrix shall test each ICA Version of Internet Explorer that it
                 develops in accordance with Microsoft's standard testing
                 procedures for final release products, and shall deliver each
                 ICA Version of Internet Explorer to Microsoft following
                 successful completion of such testing. Upon receipt of an ICA
                 Version of Internet Explorer that has passed such testing,
                 Microsoft shall have thirty (30) business days in which to
                 notify Citrix that it intends to distribute a Microsoft version
                 of Internet Explorer that incorporates the modifications made
                 by Citrix. If Microsoft does not so notify Citrix within the
                 foregoing thirty (30) day period, then Citrix may notify
                 Microsoft that Citrix desires to obtain a license to reproduce
                 and distribute such ICA Version of Internet Explorer in Object
                 Code form, which shall be on Microsoft's standard distribution
                 terms for this software [CONFIDENTIAL TREATMENT REQUESTED]/*/,
                 including without limitation any use by Citrix of the Internet
                 Explorer logo and the end user license under which Citrix would
                 distribute the applicable ICA Version of Internet Explorer.

          4.3.3  [CONFIDENTIAL TREATMENT REQUESTED]/*/ If the parties cannot
                 agree upon a suitable payment, after good faith efforts, within
                 ninety (90) days of the start of negotiations, any reproduction
                 and distribution rights granted to Citrix for an ICA Version of
                 Internet Explorer shall terminate automatically.

- ----------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
    AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED
    MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2
    PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                      -9-

     4.4  Windows NT Server and Hydrix Source Code.  Microsoft hereby grants to
          ----------------------------------------                             
          Citrix, under Microsoft's intellectual property rights (other than
          trademarks), a world-wide, non-exclusive, [CONFIDENTIAL TREATMENT
          REQUESTED]/* /license during the term of this Agreement to:  (i) use
          and copy the Windows NT Server Source Code and Hydrix Server Source
          Code delivered by Microsoft to Citrix hereunder, in read only format,
          as a reference in the design or development of Plug-In Software, and
          (ii) use, copy, and create derivative works of the Windows NT Server
          Source Code and Hydrix Server Source Code delivered by Microsoft to
          Citrix hereunder in support of the joint development of the Hydrix
          Plug-In Interfaces as described in Section 3.2 and the development of
          proposed design enhancements to the base Hydrix Multi-User
          functionality as described in Section 3.3.

     4.5  Source Code Rights.  Subject to Section 10.3, the term of the license
          ------------------                                                   
          agreement between Citrix and Microsoft dated November 15, 1989
          (Contract No. 5198-9228), as amended, shall be extended until
          September 30, 2001 for Windows NT Server version 3.5 1.

     4.6  Additional Tools.  In the event Microsoft or Citrix develops or
          ----------------                                               
          acquires any software tools which would assist the other party in
          performing its development and testing responsibilities under this
          Agreement in a timely manner, Microsoft or Citrix shall consider in
          good faith the possibility of licensing such tools to the other party
          without charge for use by that party's employees and consultants in
          performing their obligations under this Agreement.  Any such licenses
          may be contingent, among other things, upon entry into further written
          license agreements governing the applicable tools and complying with
          all applicable license restrictions.

     4.7  Drivers and Header Files of Citrix' WinFrame 1.6 and WinFrame 2.0/4.0.
          ---------------------------------------------------------------------
          With respect to Windows NT video device drivers and header files that
          are presently incorporated into WinFrame 1.6 or WinFrame 2.0/4.0 and
          for which there are reasonable equivalents in generally available
          Microsoft software development kits ("Incorporated Files"), and for
          Microsoft-developed and owned sample device driver code and header
          files available in standard Microsoft device driver kits ("Device
          Drivers/Headers"), Microsoft hereby grants to Citrix, under
          Microsoft's intellectual property rights (other than trademarks), the
          following world-wide, non-exclusive, perpetual, irrevocable,
          [CONFIDENTIAL TREATMENT REQUESTED]/*/ rights:  (i) to make, use, copy,
          import, distribute (directly or indirectly), license, sell, offer to
          sell, rent or lease Incorporated Files and Device Drivers/Headers, in
          Object Code form, solely for incorporation into Plug-In 

- ----------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
    AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED
    MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2
    PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                      -10-

          Software; and, (ii) to sub-license Citrix Plug-In Software containing
          Incorporated Files and Device Drivers/Headers.

     4.8  Further Patent Licenses.  Each of the parties agrees to enter into the
          -----------------------                                               
          Patent License Agreement attached hereto as Exhibit F as a condition
          to the effectiveness of each of the license grants set forth in this
          Section 4.

     4.9  Trademark Use.  The parties will use good faith efforts to enter into
          -------------                                                        
          appropriate trademark agreements in support of the activities
          anticipated by this Agreement.

5    Ownership
     ---------

     5.1  Existing Rights.  All intellectual property rights which each party
          ---------------                                                    
          owns as of the Effective Date of this Agreement shall remain the sole
          and exclusive property of such party and no licenses are granted or
          implied, other than those expressly granted herein or in other written
          agreements between the parties.

     5.2  Work Under This Agreement.  With the exception of (i) Citrix Plug-In
          -------------------------                                           
          Software, (ii) any component or implementation of ICA developed by
          Citrix, and (iii) any other Citrix value added software not
          encompassed by the scope of Exhibits C or D, Citrix hereby irrevocably
          assigns to Microsoft, its successors and assigns, all right, title and
          interest in and to all Inventions, copyrighted materials, and other
          intellectual property created by Citrix employees or contractors
          participating in the development of Hydrix and related work as
          described in Exhibits C and D, or in the course of developing any Key
          System Client Software port as described in Section 4.2 or ICA Version
          of Internet Explorer as described in Section 4.3.  Citrix hereby
          irrevocably transfers and assigns to Microsoft any and all "moral
          rights" that Citrix may have in all Inventions, copyrighted materials,
          and other intellectual property which it assigns to Microsoft under
          the previous sentence, and Citrix also forever waives and agrees never
          to assert any and all such "moral rights" which it may retain
          notwithstanding the previous clause, regardless of the termination or
          expiration of this Agreement.  Citrix will execute and deliver such
          instruments and take such other actions as may be requested by
          Microsoft to perfect or protect Microsoft's rights and to carry out
          the assignments effected by this Section 5.2.

6    Confidentiality
     ---------------

     6.1  Confidentiality Obligations.  Each party expressly undertakes to
          ---------------------------                                     
          retain in confidence all non-public information and know-how disclosed
          by the other party to it that has been designated as proprietary
          and/or confidential or that, by the nature of the circumstances
          surrounding the disclosure, ought in good faith to be treated as
          proprietary and/or confidential (the "Confidential Information"), and
          will make no use of such information except as permitted under the
          terms of this Agreement.  Without limiting the generality of the
          foregoing, Confidential Information includes the terms and conditions
          of this Agreement and all 

<PAGE>
 
                                      -11-

          agreements between the parties referenced herein (subject, in each
          case, to any obligations of the parties to disclose such information,
          and to the limited extent so required, under any applicable rules of
          the Securities and Exchange Commission and any securities exchange on
          which the securities of such party are then or at any time hereafter
          traded), and all Source Code provided by either party to the other in
          connection with this Agreement. Each party shall use its best efforts
          to protect Confidential Information of the other party, which efforts
          shall be at least as great as the precautions it takes to protect its
          own confidential information. Each party may disclose the other
          party's Confidential Information only to its employees and contractors
          under suitable non-disclosure agreement on a "need to know" basis.
          Each party may also disclose such Confidential Information as required
          by government or judicial order, provided each party gives the other
          party prompt notice of such disclosure and cooperates with the other
          party in seeking protective orders and other means to prevent or limit
          such disclosures. Each party shall notify the other party promptly
          upon the discovery of any unauthorized use or disclosure of the other
          party's Confidential Information, and will cooperate with the other
          party in every reasonable way to assist the other party in regaining
          possession of such Confidential Information and to prevent future
          unauthorized use or disclosures.

     6.2  Microsoft Source Code Confidentiality.  Subject to any licenses
          -------------------------------------                          
          granted under Section 4, in addition to the protections afforded to
          Confidential Information pursuant to Section 6.1 above, Citrix
          undertakes the following additional obligations with respect to
          Microsoft Source Code received hereunder:  Citrix shall not reproduce,
          duplicate, copy or otherwise disclose, distribute or disseminate
          Microsoft Source Code in any media except for Citrix' own internal use
          by Citrix' full-time employees, and consultants which have been
          approved in advance by Microsoft, under suitable non-disclosure
          agreements on a need-to-know basis on Company premises.  Citrix shall
          make only two (2) archival copies of each version of Microsoft Source
          Code, all of which shall be stored in a vault.  The Microsoft Source
          Code shall be controlled by Citrix using a reasonable control and
          security procedure.

     6.3  Hydrix Plug-In Interface.  The Hydrix Plug-In Interface is
          ------------------------                                  
          [CONFIDENTIAL TREATMENT REQUESTED]/*/ , and, reflecting the nature of
          the joint development under this Agreement, [CONFIDENTIAL TREATMENT
          REQUESTED]/*/, provided however that [CONFIDENTIAL TREATMENT
          REQUESTED]/*/ by either party which do not grant a license or permit
          the use of 

- ----------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
    AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED
    MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2
    PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                      -12-

          the Hydrix Plug-In Interface shall not be deemed [CONFIDENTIAL
          TREATMENT REQUESTED]/*/.

     6.4  Exclusions.  Confidential Information shall not include that
          ----------                                                  
          information defined as Confidential Information above which:  (i)
          became generally publicly available without the receiving party's
          breach of any obligation owed to the disclosing party under this
          Agreement; (ii) became known to the receiving party prior to the
          disclosure of such information; (iii) became known to the receiving
          party from a third party other than by the breach of an obligation of
          confidentiality owed under this Agreement; or (iv) was independently
          developed by the receiving party.

     6.5  Residuals.  The terms of confidentiality under this Agreement shall
          ---------                                                          
          not be construed to limit either party's right to independently
          develop or acquire products without use of the other party's
          Confidential Information.  Further, either party shall be free to use
          for any purpose the residuals resulting from access to or work with
          such Confidential Information, provided that such party shall maintain
          the confidentiality of the Confidential Information as provided
          herein, except to the extent that disclosure is inherent from selling,
          licensing or otherwise disposing of a product using or incorporating
          such residuals.  The term "residuals" means information in non-
          tangible form which may be retained by persons who have had access to
          the Confidential Information, including ideas, concepts, know-how or
          techniques contained therein.  Neither party shall have any obligation
          to limit or restrict the assignment of such persons or to pay
          royalties for any work resulting from the use of residuals or the sale
          of products using or incorporating residuals. However, the foregoing
          shall not be deemed to grant to either party a license under the other
          party's copyrights or patents.

7    Technical Coordinators; Executive Oversight; Marketing Liaisons
     ---------------------------------------------------------------

     7.1  The Technical Coordinators for the parties are:

     For Citrix:

               [CONFIDENTIAL TREATMENT REQEUSTED]/*/

     For Microsoft:

               [CONFIDENTIAL TREATMENT REQUESTED]/*/

- ----------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
    AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED
    MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2
    PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                      -13-

     7.2  The Technical Coordinators shall be responsible for:

          7.2.1  Submission and acceptance of materials required to be delivered
                 under this Agreement;

          7.2.2  Arranging such meetings, visits and consultations between
                 Microsoft and Citrix personnel associated with the work to be
                 performed under this Agreement as may be deemed necessary or
                 desirable for successful accomplishment of such work; and

          7.2.3  Preparation of amended Exhibits and submission of amended
                 Exhibits to Named Executives for approval as provided below.

     7.3  The Named Executives for the parties are:

     For Citrix:

               [CONFIDENTIAL TREATMENT REQUESTED]/*/

     For Microsoft:

               [CONFIDENTIAL TREATMENT REQUESTED]/*/

     7.4  The Named Executives shall be responsible for:

          7.4.1  Prompt resolution of any and all issues that arise in the
                 course of the work to be performed hereunder and that cannot be
                 resolved by the parties' respective Technical Coordinators; and

          7.4.2  Approval of any and all amendments to the Exhibits to this
                 Agreement.

     7.5  Amendment of the terms and conditions set forth in the body of this
          Agreement are not within the authority of the Technical Coordinators.
          Any modification of the terms set forth herein shall be reduced to a
          formal written amendment and executed by authorized representatives of
          the corporations.

     7.6  No alteration of the terms of any Exhibit shall be effective until and
          unless an amended Exhibit is initialed and dated by the Named
          Executive of both parties.

- ----------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
    AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED
    MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2
    PROMULGATED UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
   
<PAGE>
 
                                      -14-



     7.7  The Marketing Liaisons for the parties are:

          For Citrix:

                     [CONFIDENTIAL TREATMENT REQUESTED]/*/


          For Microsoft:
                    
                     [CONFIDENTIAL TREATMENT REQUESTED]/*/

     7.8  The Marketing Liaisons shall be responsible for fulfilling the
          parties' obligations under Exhibit E.

     7.9  Each party shall advise the other in writing of any successor or
          designee of their respective Technical Coordinators, Named Executives
          or Marketing Liaisons.

8    Covenants
     ---------

     8.1  In order to facilitate the exchange of information and the joint
          development work to be performed hereunder, and in consideration of
          the terms and conditions of this Agreement, the parties shall abide by
          the following covenants during the term of this Agreement (unless
          otherwise specified below):

     8.2  Hydrix shall support ICA in an equitable manner in comparison to the
          support provided by such server offerings for other protocols of
          Microsoft or third party clients.

     8.3  Microsoft will [CONFIDENTIAL TREATMENT REQUESTED]/*/ to allow client
          devices implementing ICA to attach to Hydrix servers.  Citrix
          acknowledges that such licensing scheme may require the use of Key
          System Client Software.  Without limiting the generality of the
          foregoing, Microsoft's [CONFIDENTIAL TREATMENT REQUESTED]/*/ for
          Windows CE Key System Client Software licenses [CONFIDENTIAL TREATMENT
          REQUESTED]/*/ in comparison to [CONFIDENTIAL TREATMENT REQUESTED]/*/
          for Key System Client Software licenses for end users of Pure ICA
          Devices.

     8.4  After Microsoft begins to market and distribute Hydrix, Microsoft
          agrees to use commercially reasonable efforts to make Hydrix available
          in at least the same set of international versions and on at least the
          same set of platforms as Windows NT Server is offered.  Microsoft will
          use commercially reasonable efforts to release

- --------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED
MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                      -15-

          such additional versions in a timely manner given the development
          requirements therefor, and provided that Microsoft in its sole
          discretion shall determine its release schedule for all versions of
          Hydrix.

     8.5  Provided that Microsoft ships a Hydrix 4.0 product and a Hydrix 5.0
          product, during the term of this Agreement, Citrix agrees to limit
          updates of its current Multi-User product (currently known as
          "WinFrame") as follows: [CONFIDENTIAL TREATMENT REQUESTED]/*/.
          "Product Release" shall mean a major release of Product which is
          designated by Citrix in its sole discretion as a change in the
          digit(s) to the left of the decimal point in the product version
          number [(x).xx]; and "Version Release" shall mean a release of Product
          containing only minor enhancements and bug fixes which is designated
          by Citrix in its sole discretion as a change in the tenths digit in
          the product version number [x.(x)x].  For as long as Citrix complies
          with the foregoing limitation, Microsoft shall provide it with Windows
          NT Server v.3.51 Source Code as necessary to develop and maintain such
          authorized WinFrame 2.0/3.51 versions in localized form.
          Notwithstanding the foregoing, if Microsoft, despite making
          commercially reasonable efforts, is unable to release (i) a Hydrix 4.0
          product within [CONFIDENTIAL TREATMENT REQUESTED] /*/ of the Effective
          Date, (ii) a Hydrix 5.0 product within the later of a) [CONFIDENTIAL
          TREATMENT REQUESTED]/*/ after initial release of a Hydrix 4.0 product
          and b) [CONFIDENTIAL TREATMENT REQUESTED]/*/ after the Effective Date,
          or (iii) a Hydrix product for the second Product Release of Windows NT
          Server following the Effective Date (currently assumed to be Windows
          NT Server v.6) within [CONFIDENTIAL TREATMENT REQUESTED]/*/ after
          initial release of Hydrix 5.0 product, then Citrix may offer, license
          and distribute [CONFIDENTIAL TREATMENT REQUESTED]/*/ of WinFrame for
          Windows NT Server v. 3.51 without violating its obligations under this
          Section.

     8.6  Provided that Microsoft is in compliance with Section 8.9, Citrix
          agrees [CONFIDENTIAL TREATMENT REQUESTED]/*/ developing or assisting
          any third party in developing, [CONFIDENTIAL TREATMENT REQUESTED]/*/
          as defined in this Agreement, without Microsoft's prior written
          consent.

     8.7  For the first [CONFIDENTIAL TREATMENT REQUESTED]/*/ after the
          Effective Date of this Agreement, Microsoft agrees to refrain from
          shipping any Multi-User client device support for any device other
          than a Windows Client Device and will not make any representation or
          announcement of its intention to develop or ship such Plug-In Software
          for [CONFIDENTIAL TREATMENT REQUESTED]/*/ after the Effective Date.

- --------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED
MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                      -16-

     8.8  Microsoft agrees to endorse only ICA as the preferred way to provide
          Multi-User Windows access for devices other than Windows Client
          Devices for a period of two and one-half (2.5) years from the
          Effective Date.

     8.9  Provided that Citrix is in compliance with Section 8.6, Microsoft
          agrees [CONFIDENTIAL TREATMENT REQUESTED]/*/ developing or assisting
          third parties in developing [CONFIDENTIAL TREATMENT REQUESTED]/*/, as
          defined in this Agreement, [CONFIDENTIAL TREATMENT REQUESTED]/*/,
          without Citrix' prior written consent.

     8.10 In the event Citrix fails to actively pursue the market for
          supporting specific client device types (e.g., Macintosh) with Citrix
          Plug-In Software and provide a commercially competitive product on
          those specific client device types on an on-going basis, Microsoft
          shall have the right to lift restrictions in Sections 6.3 and 8.7 for
          those affected client device types upon written notice to Citrix,
          provided Citrix does not cure such failure within [CONFIDENTIAL
          TREATMENT REQUESTED]/*/ of notice or a technically reasonable time
          period.

     8.11 Microsoft agrees to make commercially reasonable efforts to bundle
          ICA client software as supplied by Citrix with Microsoft Windows
          family products during the term of the Agreement, provided that
          Microsoft shall not be obligated to do so if such bundling materially
          increases product costs and/or materially increases end-user
          electronic download times.  Microsoft shall offer this through its
          standard delivery mechanisms, but not require its OEMs to bundle such
          client software.

     8.12 Microsoft shall continue to make Hydrix 4.x products commercially
          available for [CONFIDENTIAL TREATMENT REQUESTED]/*/ beyond the release
          (if any) of Hydrix 5.0 and Hydrix 5.x for [CONFIDENTIAL TREATMENT
          REQUESTED]/*/ beyond the release of Hydrix products for the second
          Product Release of Windows NT Server following the Effective Date
          (currently assumed to be Windows NT Server v.6).

     8.13 Microsoft covenants that it will not distribute a Multi-User server
          which provides Multi-User access to Windows-based applications during
          the term of this Agreement other than the Multi-User Windows NT
          defined as Hydrix herein, unless such server is a functional
          replacement, including the Hydrix Plug-In Interfaces, for Hydrix that
          provides access to Windows-based applications and is distributed
          subject all terms of this Agreement including Section 9.

- --------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED
MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                      -17-

9    Payment
     -------

     9.1  Fees.  In consideration of Citrix' development obligations, license
          ----                                                               
          grants, and the other terms and conditions of this Agreement,
          Microsoft agrees to pay the fees set forth in this Section 9 during
          the term of this Agreement.

          9.1.1  Microsoft shall pay initial fees and royalties to Citrix within
                 thirty (30) days of the Effective Date, as follows:

                 9.1.1.1  The sum of Thirteen Million Dollars ($13,000,000) for
                          engineering services to be provided by Citrix to
                          Microsoft for Hydrix products as defined in Exhibits C
                          and D, such amount to be due and payable without
                          regard to shipment by Microsoft of any Hydrix products
                          described herein.

                 9.1.1.2  The sum of Sixty Two Million Dollars ($62,000,000) as
                          an initial non-refundable royalty payment, the full
                          amount of such payment to be irrespective of the
                          number of units or dollar amount of any Hydrix
                          products shipped, if any, by Microsoft hereunder.

          9.1.2  Subject to the other terms and conditions of this Agreement,
                 Microsoft shall pay the following additional royalties to
                 Citrix with respect to Microsoft's distribution of Hydrix:

                 9.1.2.1  For Hydrix products which Microsoft prices separately
                          and the primary function of which is to add Multi-User
                          functionality to applicable versions of Windows NT
                          Server ("Add-on Products"), Microsoft shall pay a
                          royalty of [CONFIDENTIAL TREATMENT REQUESTED]/*/ of
                          its Net Receipts from distribution of such products.

                 9.1.2.2  Microsoft shall pay Citrix an additional royalty of
                          [CONFIDENTIAL TREATMENT REQUESTED]/*/ of its Net
                          Receipts from licenses that enable customers to attach
                          Hydrix client devices to a Hydrix Server and execute
                          Windows applications on such servers (but excluding
                          Net Receipts from any other Microsoft software which
                          may be distributed or licensed in conjunction with the
                          right to attach and execute Windows applications on
                          the server).

- --------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED
MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                      -18-

                 9.1.2.3  In each quarter, Microsoft shall calculate the
                          revenues Citrix would have been due from a royalty of
                          [CONFIDENTIAL TREATMENT REQUESTED]/*/. If, in a given
                          quarter, this alternative royalty would have exceeded
                          that sum due to Citrix under Sections 9.1.2.1 and
                          9.1.2.2, then this alternative royalty shall apply.

                 9.1.2.4  Within forty five (45) days after the end of each
                          calendar quarter with respect to which Microsoft owes
                          Citrix any royalties hereunder, Microsoft shall
                          furnish Citrix a statement together with payment for
                          any amount shown thereby to be due to Citrix. The
                          royalty statement shall be based upon Net Receipts for
                          the quarter then ended, and shall contain information
                          sufficient to discern how the royalty payment was
                          computed in a form agreed upon.

                 9.1.2.5  Microsoft shall not be obligated to pay any royalties
                          to Citrix with respect to (i) any product which is
                          distributed as "free," "complimentary," "no charge,"
                          or at nominal prices to cover shipping and handling,
                          in support of normal marketing activities, or (ii) MS'
                          internal use and sale to employee copies. Microsoft
                          shall be entitled to withhold from all royalty sums
                          otherwise payable hereunder a reasonable reserve, made
                          in good faith, against anticipated returns of Hydrix
                          products and Key System Client Software which it
                          distributes, provided that such reserve shall not
                          exceed fifteen percent (15%) of all amounts due
                          hereunder for the two (2) most recent calendar
                          quarters, without adjustment for reserve, and which
                          reserve shall be reviewed quarterly in light of the
                          actual returns of the preceding two (2) quarters. The
                          excess (short-fall), if any, of such reserve balance
                          at the time of such quarterly review over (under) the
                          actual aggregate amount of returns for such period
                          shall be credited to (debited against) the next
                          payment due Citrix hereunder.

     9.2  Minimum and Maximum Payments.
          ---------------------------- 

          9.2.1  In the event that during any of the five calendar quarters
                 after the commercial release of Hydrix 4.0, Microsoft's payment
                 of fees with respect to Hydrix 4.x products for such quarter
                 does not equal at least [CONFIDENTIAL TREATMENT REQUESTED]/*/ ,
                 Microsoft shall within forty-five (45) days after the end of
                 such calendar quarter pay an additional amount to Citrix such
                 that the cumulative payment for such 

- --------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED
MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                      -19-

                 quarter equals [CONFIDENTIAL TREATMENT REQUESTED]/*/. Once
                 Microsoft has made payments to Citrix hereunder totaling Fifty
                 Million Dollars ($50,000,000.00) for royalty-bearing products
                 associated with Hydrix 4.x, Microsoft's obligation to make any
                 further payments under Section 9.1.2 associated with Hydrix 4.0
                 shall cease.

                 9.2.1.1  Notwithstanding the provisions of the foregoing
                          paragraph, if Citrix achieves delivery of Hydrix 4.0
                          which is accepted by Microsoft (such acceptance not to
                          be unreasonably withheld) prior to [CONFIDENTIAL
                          TREATMENT REQUESTED]/*/ , then any unearned portion of
                          Hydrix royalties remaining payable on Hydrix 4.0 below
                          $50 Million, shall be added to the $50 Million Dollar
                          cap on royalties to be paid to Citrix on Hydrix 5.0.

          9.2.2  In the event that during any of the five calendar quarters
                 after the commercial release of Hydrix 5.0, Microsoft's payment
                 of fees with respect to Hydrix 5.x products for such quarter
                 does not equal at least [CONFIDENTIAL TREATMENT REQUESTED]/*/,
                 Microsoft shall within forty-five (45) days after the end of
                 such calendar quarter pay an additional amount to Citrix such
                 that the cumulative payment for such quarter equals
                 [CONFIDENTIAL TREATMENT REQUESTED]/*/. Except as provided in
                 Section 9.2.1.1 above, once Microsoft has made payments to
                 Citrix hereunder totaling Fifty Million Dollars
                 ($50,000,000.00) for royalty-bearing products associated with
                 Hydrix 5.0, Microsoft's obligation to make any further payments
                 under Section 9.1.2 associated with Hydrix 5.0 shall cease.

     9.3  Further Payment.  In no case shall Microsoft be required to make any
          ---------------                                                     
          payments on major Product Release of Hydrix beyond version 5.x, or any
          amount in excess of $175 Million Dollars under this Agreement.

     9.4  Address for Payments.  Payments provided for in this Section shall be
          --------------------                                                 
          made electronically to an address and account to be provided by
          Citrix.

     9.5  Taxes.  Payments provided for in this Section are exclusive of any
          -----                                                             
          federal, state, municipal or other governmental taxes.

- --------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED
MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                      -20-

     9.6   Audits.
           ------ 

           9.6.1  During the term of this Agreement and for three (3) years
                  thereafter, Microsoft agrees to keep all usual and proper
                  records and books of account and all usual and proper entries
                  relating to Hydrix sufficient to substantiate the number of
                  copies of Hydrix, distributed or otherwise disposed of by or
                  for Microsoft. Microsoft shall maintain such records for
                  itself and for each Microsoft subsidiary which exercises
                  rights under this Agreement.

           9.6.2  In order to verify statements issued by Microsoft and
                  Microsoft's compliance with the terms of this Agreement, upon
                  prior written notice to Microsoft, Citrix may cause (i) an
                  audit to be made of Microsoft's and/or Microsoft's
                  subsidiaries' books and records; and/or (ii) an inspection to
                  be made of Microsoft's and/or Microsoft's subsidiaries'
                  facilities and procedures. Any audit and/or inspection shall
                  be conducted during regular business hours at Microsoft's
                  and/or Microsoft's subsidiaries' facilities. Any audit shall
                  be conducted by a nationally recognized independent certified
                  public accountant selected by Citrix (other than on a
                  contingent fee basis).

           9.6.3  Microsoft agrees to provide Citrix' designated audit or
                  inspection team access to the relevant Microsoft and/or
                  Microsoft subsidiaries' records and facilities.

           9.6.4  Prompt adjustment shall be made to compensate for any errors
                  or omissions disclosed by such audit. Any such audit shall be
                  paid for by Citrix unless material discrepancies are
                  disclosed. "Material" shall mean more than five percent (5%)
                  of the amount that was reported. If material discrepancies are
                  disclosed, Microsoft agrees to pay Citrix for the costs
                  associated with the audit. In no event shall audits be made
                  more frequently than annually.

10   Term, Termination, and Limitation of Remedies
     ---------------------------------------------

     10.1  The term of this Agreement shall commence as of the Effective Date
           and shall continue for a period of [CONFIDENTIAL TREATMENT
           REQUESTED]/*/ , unless terminated in accordance with the provisions
           of this Section 10 or extended by a mutually agreed amendment hereto.

     10.2  After escalation to the parties' Named Executives, including a
           presentation by each party to the Named Executive of the other party
           of their respective concerns, 

- --------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED
MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                      -21-

           either party may terminate this Agreement if the other party is in
           material breach of any term or condition of this Agreement and fails
           to cure that breach within ninety (90) days after receipt of written
           notice thereof.

     10.3  In the event that Citrix ships a Product Release incorporating
           technology from Microsoft Windows NT Server version 3.51, except as
           permitted by Section 8.5, (i) Citrix' rights to Windows NT Server
           v.3.51 Source Code and Object Code, as they exist as of the Effective
           Date under this Agreement, will be extended by an additional
           [CONFIDENTIAL TREATMENT REQUESTED]/*/ from the date they would
           otherwise expire; (ii) all of Microsoft's further payment obligations
           to, Citrix under Sections 9.1 and 9.2 shall immediately terminate and
           Microsoft's licenses under this Agreement shall thereafter be 
           royalty-free; and (iii) all of Microsoft's obligations under Sections
           6.3, 8.7, and 8.8 shall immediately cease.

     10.4  Citrix may, at its option, also invoke the remedies set forth in
           Section 10.3(i), (ii), and (iii) at any time in its sole discretion,
           provided that such election of remedies shall be Citrix' sole and
           exclusive remedy in the event of any breach by Microsoft of Section
           8.3 or its development obligations hereunder.

     10.5  The following Sections shall survive any expiration or termination of
           this Agreement in accordance with their terms: Sections 1, 4.1, 4.2,
           4.5, 5, 6 (excluding 6.3), 10, 11, 12, 13, 14.1, 15, 16, 17, 19, 22,
           and Exhibit F (Patent License). Section 21 shall survive according to
           its terms.

11   Warranties
     ----------

     11.1  Each party represents and warrants that:

           11.1.1  It has full power to enter into this Agreement and grant the
                   license rights set forth herein:

           11.1.2  It has not previously and will not grant any rights to any
                   third party that are in conflict with the rights granted to
                   the other party herein;

           11.1.3  The information or materials delivered to the other party
                   hereunder do not (i) infringe any copyright enforceable under
                   the laws of the countries listed in Section 11.3; (ii)
                   violate any trade secret right of any third party, or (iii)
                   to the best of the delivering parties' knowledge infringe any
                   patent right of any third party as of the Effective Date.

     11.2  EXCEPT AS PROVIDED IN SECTION 11.1 ABOVE, THE INFORMATION AND
           MATERIALS DELIVERED BY EACH PARTY TO THE OTHER 

- --------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED
MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                      -22-

           PURSUANT TO THIS AGREEMENT ARE PROVIDED "AS IS" WITHOUT WARRANTY OF
           ANY KIND. ANY REPRESENTATIONS OR WARRANTEES MADE BY EITHER PARTY TO
           ITS CUSTOMERS, EXPRESS OR IMPLIED, BY LAW OR OTHERWISE, REGARDING
           INTELLECTUAL PROPERTY ARE THE SOLE RESPONSIBILITY OF SUCH PARTY. EACH
           PARTY DISCLAIMS ALL OTHER WARRANTIES OF MERCHANTABILITY AND FITNESS
           FOR A PARTICULAR PURPOSE.

     11.3  Neither party shall have any obligation to the other for any
           copyright infringement claim made against the other which arises from
           the use or distribution of products outside the geographical
           boundaries of the United States, Canada, Australia, Japan, the
           European Economic Community, Sweden, Norway, and Finland, and each
           party hereby releases and discharges the other from any and all
           copyright infringement claims resulting from such use or
           distribution.

12   Indemnity
     ---------

     12.1  Each party shall (the "Indemnifying Party"), at its expense and upon
           request, defend any claim or action brought against the other party,
           and the other party's subsidiaries, affiliates, directors, officers,
           employees, agents and independent contractors (the "Indemnified
           Party"), which, if true, would constitute a breach of a warranty set
           forth in Section 11, and the party will indemnify and hold the other
           party harmless from and against any costs, damages and fees
           reasonably incurred by the other party, including but not limited to
           fees of attorneys and other professionals, that are attributable to
           such claim; provided that: (i) the Indemnified Party provides the
           Indemnifying Party with reasonably prompt notice in writing of any
           such claim or action and permits the Indemnifying Party, through
           counsel reasonably acceptable to the Indemnified Party, to answer and
           defend such claims or action; and (ii) the Indemnified Party provides
           the Indemnifying Party information, assistance and authority to help
           the Indemnifying Party to defend such claim or action. The
           Indemnifying Party shall reimburse the Indemnified Party upon demand
           for any payments made or loss suffered by the Indemnified Party at
           any time after the date hereof in respect of any liability or claim
           to which the foregoing indemnity relates, and which has resulted in
           an adverse judgment of a court of competent jurisdiction or has been
           settled with the consent of the Indemnifying Party.

     12.2  The Indemnified party shall have the right to employ separate counsel
           and participate in the defense of any claim or action at its expense.

     12.3  Following notice of an Infringement Claim, the Indemnifying Party
           may, at its expense, without obligation to do so, procure for the
           Indemnified Party the right to continue to market, use and have
           others use the information or materials claimed to be infringing or,
           without obligation to do so, may replace any information or materials
           to make them non-infringing. If the Indemnifying Party 

<PAGE>
 
                                      -23-

           elects to replace or modify any information or materials, such
           replacement shall meet substantially the specifications for such
           information or materials provided for in this Agreement, if any, and
           shall be subject to any acceptance provisions of this Agreement
           applicable to the delivery of such information or materials.

     12.4  Neither party shall have any liability for any infringement claim
           based on the other party's (i) use or distribution of products after
           receipt of notice from the other party that the party should cease
           use or distribution of the product due to an infringement claim; or
           (ii) combination of information or materials delivered by the other
           party hereunder with other programs or data, if such infringement
           claim would have been avoided by the exclusive use of the information
           or materials delivered hereunder. For all infringement claims arising
           under this Section 12.4, the other party agrees to indemnify and
           defend the delivering party from and against all damages, costs and
           expenses, including reasonable attorneys' fees.

13   Limitation of Liability; Actions
     --------------------------------

     13.1  Except with respect to Section 21 and breach of Section 6.1, 6.2, and
           6.3 (subject to 13.2), NEITHER PARTY SHALL BE LIABLE FOR ANY
           INDIRECT, INCIDENTAL, CONSEQUENTIAL, PUNITIVE OR SPECIAL DAMAGES,
           EVEN IF SUCH PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
           DAMAGES IN ADVANCE. The parties acknowledge that other parts of this
           Agreement rely upon the inclusion of this Section.

     13.2  Notwithstanding Section 13.1, Citrix may recover against Microsoft
           indirect, incidental, consequential, or special damages that are
           awarded by a court of competent jurisdiction following exhaustion of
           all appeals to which Microsoft is entitled, up to a total cap of
           [CONFIDENTIAL TREATMENT REQUESTED]/*/ for any uncured, material
           breach of Section 6.3.

     13.3  Nothing in this Agreement shall affect or limit either party's right
           to collect any amounts otherwise due under the terms of this
           Agreement or to institute and prosecute proceedings in any court of
           competent jurisdiction (as provided in Section 19), under any
           applicable laws, seeking direct damages for breach of this Agreement,
           specific performance of this Agreement, or an order enjoining the
           other party from activities in violation of this Agreement.

14   Agreements with Employees and Others
     ------------------------------------

     14.1  Each party represents that it has or will obtain appropriate
           agreements with its employees or others including subcontractors,
           whose services it may require, 

- --------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED. ALL SUCH OMITTED
MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                      -24-

           sufficient to enable such party to comply with all the provisions of
           this Agreement.

     14.2  Personnel used or supplied by Microsoft in the performance of work
           hereunder shall be employees or contractors of Microsoft, and under
           no circumstances are such personnel to be considered employees or
           agents of Citrix. Microsoft shall have the sole responsibility for
           supervision and control of its personnel, payment of salary,
           including withholding of income taxes and social security taxes,
           worker's compensation, disability benefits and the like.

     14.3  Personnel used or supplied by Citrix in the performance of work
           hereunder shall be employees or contractors of Citrix, and under no
           circumstances are such personnel to be considered employees or agents
           of Microsoft. Citrix shall have the sole responsibility for
           supervision and control of its personnel, payment of salary,
           including withholding of income taxes and social security taxes,
           worker's compensation, disability benefits and the like.

     14.4  Neither Microsoft nor Citrix shall knowingly and intentionally induce
           any Engineer (as defined below) to terminate his or her employment
           with the other party while such person is serving as an Engineer,
           provided that it shall not be a breach of this Section for either
           party to hire an Engineer of the other party who has responded to
           general advertisements or has applied for a position via normal
           recruitment channels. An "Engineer" refers to a development or test
           engineer who has significant experience in working with Multi-User
           technology.

15   No Partnership, Joint Venture or Franchise
     ------------------------------------------

     Neither this Agreement, nor any terms and conditions contained herein,
     shall be construed as creating a partnership, joint venture or agency
     relationship or as granting a franchise as defined in the Washington
     Franchise Investment Protection Act, RCW 19.100, as amended, or 16 CFR
     Section 436.2(a).

16   Compliance with Laws and Regulations
     ------------------------------------

     Each party agrees that it will not export or re-export any product or
     technical data of the other party to any country, person, entity or end
     user to which such export would be a violation of any applicable export
     restriction. Restricted countries for purposes of U.S. law and regulations
     currently include, but are not necessarily limited to, Cuba, Iran, Iraq,
     Libya, North Korea, the Sudan, and Syria. Each party further agrees to do
     all things necessary to comply with all applicable laws, rules and
     regulations concerning exports of products and technical data of the other
     party.

17   Notices
     -------

     17.1  All notices and requests in connection with this Agreement shall be
           deemed given as of the day they are received either by messenger,
           delivery service, or in the 

<PAGE>
 
                                      -25-

          United States of America mails, postage prepaid, certified or
          registered, return receipt requested, and addressed as follows:

          To Citrix:

               Citrix Systems, Inc.
               6400 NW 6th Way
               Fort Lauderdale, Florida 33309

               Attention: President

               Phone:  (954) 267-3000
               Fax:    (954) 267-9319

               Copy to: General Counsel, George W. Thibeault
               Fax:   (617) 248-7100

          To Microsoft:

               Microsoft Corporation
               One Microsoft Way
               Redmond, WA 98052-6399

               Attention:  Group Vice President, Platforms

               Phone:  (425) 882-8080
               Fax:    (425) 936-7329

               Copy to: Law & Corporate Affairs
               Fax:(425) 936-7409

          17.1.1  or to such other address as a party may designate pursuant to
                  this notice provision.

18   Excusable Delays
     ----------------

     Neither party hereto shall be in default by reason of any failure in the
     performance hereunder in accordance with any terms, if such failure is due
     to, acts of the public enemy, acts of the Government in either its
     sovereign or contractual capacity, fires, floods, epidemics, quarantine
     restrictions, freight embargoes, civil commotions and the like.

19   Governing Law; Jurisdiction; Attorneys' Fees
     --------------------------------------------

     This Agreement shall be governed by the laws of the State of Washington as
     though entered into between Washington residents and to be performed
     entirely within the State of Washington.  In any formal action or suit to
     enforce any right or remedy under this Agreement or to interpret any
     provision of this Agreement (i) the prevailing party shall be 

<PAGE>
 
                                      -26-

     entitled to recover its costs, including reasonable attorneys' fees, and
     (ii) the party bringing the action shall bring the action in a court in the
     state and county where the other party's corporate headquarters is located.

20   Assignment
     ----------

     20.1  Neither party shall assign or otherwise transfer any of its rights or
           privileges under this Agreement, including the patent licenses
           granted hereunder, to any third party, under action of law or
           otherwise, including without limitation in connection with any
           acquisition of a party by a third party (including without limitation
           by merger, sale of stock, or otherwise) or in connection with the
           insolvency or bankruptcy of either of the parties, without the prior
           written consent of the other party. An assignment shall be deemed to
           include Citrix' acquisition of a controlling interest in a company
           listed on Exhibit H. Microsoft may revise the list on Exhibit H upon
           notice to Citrix, but may not increase the number of companies on the
           list may not add companies to the list more often than quarterly, and
           may not add a company to the list if, at that time, Citrix can
           demonstrate that it is already in acquisition discussions with such
           company for as long as such negotiation discussions continue. Any
           attempted assignment in derogation of the foregoing shall be void.

     20.2  This Section shall supersede the equivalent section in any contracts
           between the parties entered into prior to the Effective Date.

21   Pre-Agreement Claims
     --------------------

     21.1  Citrix covenants and agrees that it (and any other person or entity
           under its direction or control, and any other person or entity which
           Citrix has engaged to act on its behalf) will not assert any claims
           against Microsoft, any Microsoft employee, or any Microsoft
           subsidiary based upon any matter that occurred prior to the Effective
           Date of this Agreement ("Pre-Agreement Claims"). Notwithstanding
           anything to the contrary in the preceding sentence, Citrix may assert
           any Pre-Agreement Claims against Microsoft, Microsoft employees, or
           Microsoft subsidiaries in the event that (a) Microsoft commits a
           material breach of the Agreement which has not been cured within
           sixty (60) days of notice of breach, and Citrix elects to terminate
           the Agreement because of such breach; or (b) Microsoft terminates the
           Agreement for any reason other than material breach by Citrix which
           has not been cured within sixty (60) days of notice of breach.

     21.2  Microsoft covenants and agrees that it (and any other person or
           entity under its direction or control, and any other person or entity
           which Microsoft has engaged to act on its behalf) will not assert any
           claims against Citrix, any Citrix employee, or any Citrix subsidiary
           based upon any matter that occurred prior to the Effective Date of
           this Agreement ("Pre-Agreement Claims"). Notwithstanding anything to
           the contrary in the preceding sentence, Microsoft may assert any Pre-
           Agreement Claims against Citrix, Citrix employees, or Citrix
           subsidiaries in the event that 

<PAGE>
 
                                      -27-

           (a) Citrix commits a material breach of the Agreement which has not
           been cured within sixty (60) days of notice of breach, and Microsoft
           elects to terminate the Agreement because of such breach; or (b)
           Citrix terminates the Agreement for any reason other than material
           breach by Microsoft which has not been cured within sixty (60) days
           of notice of breach.

     21.3  This Section 21 shall survive expiration of the five-year term of the
           Agreement but shall not survive termination for breach of the
           Agreement.

22   Construction
     ------------

     If for any reason a court of competent jurisdiction finds any provision of
     this Agreement, or portion thereof, to be unenforceable, that provision of
     the Agreement will be enforced to the maximum extent permissible so as to
     effect the intent of the parties, and the remainder of this Agreement will
     continue in full force and effect. Failure by either party to enforce any
     provision of this Agreement will not be deemed a waiver of future
     enforcement of that or any other provision. This Agreement has been
     negotiated by the parties and their respective counsel and will be
     interpreted fairly in accordance with its terms and without any strict
     construction in favor or against either party.

23   Entire Agreement
     ----------------

     This Agreement constitutes the entire agreement between the parties with
     respect to its subject matter and merges all prior and contemporaneous
     communications, and this Agreement supersedes those provisions of the
     License, Development, and Marketing Agreement dated July 9, 1996 between
     the parties pertaining to Microsoft's distribution of a Multi-User product.
     It shall not be modified except by a written agreement dated subsequent to
     the date of this Agreement and signed on behalf of Citrix and Microsoft by
     their respective duly authorized representatives.

Except as otherwise provided in this Agreement, nothing in this Agreement shall
modify any agreement between the parties entered into prior to the Effective
Date.

                 [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK.]

<PAGE>
 
                                      -28-

IN WITNESS WHEREOF, the parties have entered into this Agreement as of the
Effective Date written above.


MICROSOFT CORPORATION               CITRIX SYSTEMS, INC.


/s/  Paul Maritz                    /s/  Edward E. Iacobucci
- -----------------------------       --------------------------------- 
By (Sign)                           By (Sign)


Paul Maritz                         Edward E. Iacobucci
- -----------------------------       --------------------------------- 
(Name (Print)                       Name (Print)


Group Vice President                Chairman
- -----------------------------       --------------------------------- 
Title                               Title


May 9, 1997                         May 9, 1997
- -----------------------------       --------------------------------- 
Date                                Date
<PAGE>
 
                                   Exhibit A

                              Citrix Deliverables
                              -------------------

Multi-User enabler Source Code from WinFrame 2.0/4.0. The Multi-User enabler
Source Code includes the Source Code that has been integrated into the Windows
NT 4.0 source base to enable Windows NT for a Multi-User execution model.
Specifically, this includes but is not limited to:

[CONFIDENTIAL TREATMENT REQUESTED]/*/

Communications Subsystem Source Code for WinFrame 2.0/4.0.  The Communications
Subsystem includes the infrastructure components used to establish and interface
with a connection-based communications stack.  Specifically, this includes:

[CONFIDENTIAL TREATMENT REQUESTED]/*/

 . To the extent of Citrix' rights therein, any and all administrative tools,
  diagnostic tools, tests, and test support systems, test harnesses, performance
  measurement and monitoring tools, and any additional software specifically
  used in development and testing of the code above.

 . Citrix' databases on application-compatibility deficiencies of all versions
  of WinFrame, including without limitation all quality, performance and
  scalability test suites used by Citrix to verify WinFrame Multi-User
  performance.

An initial delivery of Citrix Deliverables (including but not limited to the
Multi-User enabler Source Code and currently available documentation) of shall
be provided by Citrix to Microsoft within [CONFIDENTIAL TREATMENT REQUESTED]/*/
business days of the Effective Date, a complete delivery shall be delivered
within [CONFIDENTIAL TREATMENT REQUESTED]/*/, and updated versions thereof shall
be delivered by Citrix to Microsoft upon availability in connection with the
parties' development obligations under this Agreement.

Other Deliverables
- ------------------

In addition to the "Citrix Deliverables" above, Citrix shall deliver the
following to Microsoft:

[CONFIDENTIAL TREATMENT REQUESTED]/*/

- --------------------------
*  [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED.  ALL SUCH OMITTED
MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                    - 30 -

                                   Exhibit B

                             Microsoft Deliverables
                             ----------------------

[CONFIDENTIAL TREATMENT REQUESTED]/*/

The foregoing deliverables shall be delivered by Microsoft as soon as reasonably
practical to Citrix, but within [CONFIDENTIAL TREATMENT REQUESTED]/*/ of the
Effective Date, and updated versions thereof shall be delivered by Microsoft to
Citrix upon availability in connection with the parties' development obligations
under this Agreement.

- ---------------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED.  ALL SUCH OMITTED
MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                    - 31 -


                                   Exhibit C

                                   Hydrix 4.0
                                   ----------

Development Responsibilities
- ----------------------------

[CONFIDENTIAL TREATMENT REQUESTED]/*/

Development Requirements
- ------------------------

As part of its development responsibilities hereunder, Citrix will:

[CONFIDENTIAL TREATMENT REQUESTED]/*/

Schedule
- --------

 . Citrix will make commercially reasonable efforts to provide an initial
  commercial release candidate of Hydrix 4.0 for final conformance testing by
  Microsoft as early as possible in order for Microsoft to be able to issue a
  commercial product release in calendar year 1997.  In the event the commercial
  release candidate product delivered by Citrix pursuant to the foregoing does
  not pass Microsoft's final conformance testing, at Microsoft's discretion,
  Citrix will provide a minimum of [CONFIDENTIAL TREATMENT REQUESTED]/*/ key
  development and/or test engineers on site at Microsoft's Redmond campus who
  will be dedicated to modifying such code in order for it to pass final
  testing, recognizing that time is of the essence in such release.

 . Citrix shall also provide to Microsoft: 1) development and milestone
  schedule within [CONFIDENTIAL TREATMENT REQUESTED]/*/, 2) weekly status
  reports, 3) monthly status meetings, 3) beta not later than [CONFIDENTIAL
  TREATMENT REQUESTED]/*/.

 . The parties acknowledge that, although time is always of the essence in
  product development, the milestones and other key checkpoint dates agreed upon
  by the parties are target dates and failure to achieve any of said target
  dates shall not constitute a breach of this Agreement.  Not withstanding the
  foregoing, each party shall act in good faith and make commercially reasonable
  efforts to achieve the target dates.  Any issues regarding a failure to
  fulfill a party' obligation to undertake commercially reasonable efforts shall
  be promptly escalated to the Named Executives for resolution.

- ---------------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED.  ALL SUCH OMITTED
MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                    - 32 -

Development Personnel and Locations
- -----------------------------------

 . Each party shall provide such technical personnel as are reasonably
  necessary to work on the premises of the other party to assist in integration
  and conformance testing of portions of the Hydrix code developed by such
  party.  Each party shall pay its own employees' salaries and expenses,
  including travel, communications, and living expenses during such site visits,
  with the exception that each party shall provide office space and appropriate
  computer equipment to employees of the other party during such site visits.

<PAGE>
 
                                    - 33 -

                                   Exhibit D

                                   Hydrix 5.0
                                   ----------

Development Responsibilities
- ----------------------------

[CONFIDENTIAL TREATMENT REQUESTED]/*/

Schedule
- --------

[CONFIDENTIAL TREATMENT REQUESTED]/*/

- ---------------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED.  ALL SUCH OMITTED
MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                    - 34 -

                                   Exhibit E

                         Joint Marketing; Announcements
                         ------------------------------

Microsoft Endorsement

 . Both companies agree to a joint press release and related events, and to
  endorse each other's solutions including migration of WinFrame customers to
  Hydrix when available, though not at the expense of their own offerings.

 . Subject to provisions of section 8, Microsoft agrees to endorse only ICA as
  the preferred way to provide Windows access to non-Windows family platforms
  for a period of two and one-half (2.5) years from the Effective Date.

Co-Marketing Partnership

 . Microsoft and Citrix will provide designated Marketing Liaisons for
  handling of all Citrix/Microsoft co-marketing programs.

Announcement

 . Microsoft and Citrix will issue a joint press release announcing the
  signing of this Agreement.

 . Microsoft and Citrix will conduct a joint press conference on a mutually
  agreed upon date and location with participation of senior executives from
  both companies announcing the signing of this Agreement.

 . Microsoft and Citrix will issue a joint press release announcing the
  availability of Hydrix 4.0.

 . Microsoft will endorse only ICA as the preferred solution for non-Windows32
  devices in one or more of the announcements above.

 . Microsoft and Citrix will post relevant news announcements on their
  Internet web sites.

 . Microsoft will provide access to appropriate marketing executives &
  managers for written and verbal comment to press and industry analysts.

Attribution

 . Microsoft shall include appropriate Citrix copyright or technology
  licensing notifications in the "Help About" box which is included Hydrix 4.0,
  in product documentation which is included in the packaging for Hydrix 4.0,
  and in any advertising and promotional materials which the parties may
  mutually agree upon for "Hydrix 4.0.

Training

 . Microsoft agrees to provide sales and technical training on Hydrix 4.x and
  5.x at no cost to the Citrix sales/systems engineering and support teams.

<PAGE>
 
                                    - 35 -

 . Citrix agrees to provide sales and technical training on Citrix Plug-In
  Software at no cost to the Microsoft sales/systems engineering and support
  teams.

 . Microsoft agrees to install Citrix Plug-In Software and to connect at least
  one ICA device to Hydrix systems installed at Microsoft customer briefing
  centers.

 . Microsoft and Citrix will jointly develop an ICA overview component to be
  included in Hydrix 4.x and 5.x end user and reseller training materials.

Promotion

 . Microsoft and Citrix agree to develop a joint promotional plan for Hydrix
  and Citrix Plug-In Software.  The promotional plan may include but is not
  limited to joint participation in:

      .  industry tradeshows,
      .  seminars,
      .  advertising,
      .  web links, and
      .  direct mail

 . Upon Microsoft's request Citrix will supply Microsoft with up to l00,000
  pieces of Citrix Plug-In Software promotional materials at no charge.

 . Microsoft will supply Citrix with soft or camera-ready master copies of
  promotional materials for reproduction and distribution by Citrix in
  conjunction with Citrix' ongoing marketing activities.

 . Microsoft will provide to Citrix at [CONFIDENTIAL TREATMENT REQUESTED]/*/ a
  minimum of [CONFIDENTIAL TREATMENT REQUESTED]/*/ Not For Resale (NFR) units of
  Hydrix 4.0 and a minimum [CONFIDENTIAL TREATMENT REQUESTED]/*/ Not For Resale
  (NFR) seed units of Hydrix 5.0, and five (5) keys to allow Pure ICA clients
  using Key System Client Software to connect for each NFR seed unit. Microsoft
  will incur no royalty obligations to Citrix on these units.

 . Microsoft will provide a page on their web site for 12 months that features
  Citrix Plug-In Software for Hydrix.

 . Citrix will provide to Microsoft at [CONFIDENTIAL TREATMENT REQUESTED]/*/
  Not For Resale (NFR) units of Citrix Plug-In Software.

 . Microsoft and Citrix will jointly provide a commercially viable
  upgrade/migration program for users of Citrix WinFrame 2.0 and previous
  WinFrame products.

- ----------------------------
/*/  [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
  AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED.  ALL SUCH OMITTED
  MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
  UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                    - 36 -

                                   Exhibit F

                            Patent License Agreement
                            ------------------------

This Patent License (the "License") is entered into as of the Effective Date by
and between Microsoft Corporation, a Washington corporation ("Microsoft"), and
Citrix Systems, Inc., a Delaware corporation ("Citrix").

WHEREAS Microsoft and Citrix each own rights in certain patents and/or patent
applications for computer software inventions related to multiple user software
systems, including the right to grant patent licenses and releases to the other,

AND WHEREAS each of the Parties expects to continue research and development
which will produce further patents or applications,

AND WHEREAS, in connection with the License, Development and Marketing Agreement
which the Parties are entering into as of the Effective Date and to which this
License is an Exhibit (the "License, Development and Marketing Agreement"), each
of the Parties wishes to be granted freedom from suit under such patents of the
other Party,

     NOW, THEREFORE, in consideration of the covenants, terms and conditions
contained in this License, the Parties agree as follows:

1.   DEFINITIONS
     -----------

     1.1. Effective Date shall mean the date upon which this License is signed,
          if simultaneously executed by the Parties, or the later of the two
          dates on which this License is signed by the Parties, if signed on
          different dates.

     1.2. Subject Patents shall mean, with respect to each party, all patents
          worldwide, including utility models but not including design patents,
          with claims directed to a Multi-User Software System or component
          thereof, issued or issuing from applications entitled to a first
          effective filing date on or before the Patent Date, under which
          patents or the applications therefore either Party or any of its
          Subsidiaries now has, or hereafter obtains, the right to grant a
          license or freedom from suit to the other Party; notwithstanding the
          foregoing definition, all patents and applications owned or controlled
          by Citrix as of the Effective Date are Citrix Subject Patents.  The
          term Subject Patents shall include all patents and patent applications
          with claims directed to the work performed by the parties under the
          License, Development and Marketing Agreement.  The term Subject
          Patents shall also include all extensions, divisionals, continuations,
          continuations-in-part, reexaminations, reissue and provisional patents
          as well as patent applications to the extent rights attach to such
          applications.

<PAGE>
 
                                    - 37 -

     1.3. Multi-User Software System shall mean the client and server
          components of a computer software system (and the functions thereof)
          in which the server separately supports multiple concurrent clients
          connected to the server and wherein (i) the clients (such as
          terminals, network computers, personal computers, network PCs, cash
          registers, etc.) comprise input and output devices, (ii) the primary
          function of the client is to provide output of, and gather input for,
          the operating system and other applications that are executing on the
          server on behalf of the client; and (iii) the end result is the
          appearance to the user of the client that the operating system and
          server application(s) are running on the client.  A Multi-User
          Software System is composed of (and limited to) the following
          functional components (which may be packaged separately or in
          combination):

          1.3.1.  A server Base Subsystem for managing multiple user memory,
                  sessions, processes and threads in an underlying operating
                  system by allocating operating system resources on behalf of
                  individual clients and server applications during the multiple
                  user session, and managing memory and other system resources
                  that are not otherwise allocated to an individual user; a Base
                  Subsystem does not include operating system components or
                  operating system functions which operating system components
                  or operating system functions are not substantially used for
                  multi-user systems, but does include the underlying operating
                  system components that have been modified or enhanced to
                  support the operations of the Base Subsystem,
          
          1.3.2.  Server Session Subsystem for creating and destroying multiple
                  user sessions, and for delivering to and collecting from
                  multiple clients, user data and control information,

          1.3.3.  Client and server Protocol Subsystems for formatting and
                  transmitting the user data and control information between the
                  clients and server, the Protocol Subsystem includes the multi-
                  user data transfer protocol used by the system, and

          1.3.4.  A Client Subsystem for cooperatively sharing actions directed
                  by or on behalf of the user and server-based programmatic
                  behavior between the multiple-user system and the other
                  systems operating on the client.

     Multi-User Software System shall not include operating system components or
     operating system functions except for those multi-user operating system
     components and functions explicitly set forth in section 1.3.1 through
     1.3.4 above. Multi-User Software System shall not include any application
     programs that may simply be executed in conjunction with a Multi-User
     Software System.

     1.4.  Combination Product shall mean a product resulting from the
           combination of Microsoft or Citrix Product(s) with a product(s)
           provided by a third party, which is not a party to this License.

     1.5.  Foundry Product shall mean a Microsoft or Citrix Product sold,
           leased, licensed or otherwise transferred by one Party (the 'Foundry
           Party") to this License, 


<PAGE>
 
                                    - 38 -

           wherein the Product is designed by or for a third party without
           substantial design input from the Foundry Party and is transferred
           (i) essentially exclusively to that third party or its customers or
           (ii) through or by the Foundry Party for the purpose of circumventing
           any patent rights of the other Party.

     1.6.  Clone Product shall mean a Party's Product (which is not a Multi-User
           Software System) designed, developed or acquired after the Effective
           Date that competes with and is a fully compatible look-alike or act-
           alike (by providing the same or substantially the same user interface
           and/or APIs) version of an Established Product of the other Party. An
           Established Product is a Product publicly released or released for
           significant public beta testing and designed, developed, or acquired
           before the introduction of the Party's Product; Clone Product shall
           exclude software, such as drivers, network protocols, etc., where
           such similarity with the user interface or APIs is dictated by
           adherence to an industry standard which was widely recognized prior
           to the release of the Party's Product. A Party's Product shall not be
           deemed to be a Clone Product solely on the basis that it provides the
           same or substantially the same functionality as a product of the
           other Party. For the purposes of this definition, neither the ICA
           protocol nor Microsoft created interfaces and protocols in Microsoft
           Windows Operating System Products shall be deemed to be an "industry
           standard." "Microsoft Windows Operating System Products" shall mean
           Windows (and successors and derivatives), Windows NT (and successors
           and derivatives), and Windows CE (and successors and derivatives).

     1.7.  Microsoft Product shall mean a software product or component thereof
           designed, developed, duplicated, manufactured or rendered by or for
           Microsoft or one of its Subsidiaries, but shall not include any
           Foundry Product or Clone Product.

     1.8.  Citrix Product shall mean a software product or component thereof
           designed, developed, duplicated, manufactured or rendered by or for
           Citrix or one of its Subsidiaries, but shall not include any Foundry
           Product or Clone Product.

     1.9.  Subsidiary shall mean a corporation, company or other entity

           1.9.1. greater than fifty percent (50%) of whose combined voting
                  power of the total voting stock (representing the right to
                  vote for the election of directors or other managing
                  authority) is, now or hereafter; owned or controlled, directly
                  or indirectly, by a Party hereto, and is actually controlled
                  or managed by such Party, but such corporation, company or
                  other entity shall be deemed to be a Subsidiary only so long
                  as such voting power, and actual control or management,
                  exists; or

          1.9.2.  which does not have outstanding shares or securities, as may
                  be the case in a partnership, joint venture or unincorporated
                  association, but greater than fifty percent (50%) of whose
                  ownership or equity interest is, now or hereafter, owned or
                  controlled, directly or indirectly, by a Party hereto,


<PAGE>

                                    - 39 -
 
                  and is actually controlled or managed by such Party, but such
                  corporation, company or other entity shall be deemed to be a
                  Subsidiary only so long as such ownership or control of equity
                  interest, and actual control or management, exists.

          1.9.3.  For the purposes of this License, the Parties agree that the
                  Microsoft Network and any other mutually agreed less than
                  majority owned affiliates listed in Exhibit A as may be
                  amended from time to time, shall each constitute a Subsidiary
                  of Microsoft so long as Microsoft maintains at least a twenty-
                  percent (20%) ownership interest in the entity.

     1.10.  Patent Date shall mean the fifth anniversary of the Effective Date
            or the date of early termination under Section 10 of the License,
            Development and Marketing Agreement, which ever is earlier.

2.   GRANTS
     ------
     2.1.  Microsoft to Citrix
           2.1.1.  Microsoft, on behalf of itself and its Subsidiaries, grants
                   Citrix a worldwide, nonexclusive, [CONFIDENTIAL TREATMENT
                   REQUESTED]/*/ , non-transferable (except as provided in
                   Section 9) license under any of Microsoft's Subject Patents
                   to practice any right under such patents including the right
                   to make, use, sell, offer for sale or import, to commercially
                   exploit; to have made, to promulgate any specification
                   related to, to provide any service, or to test any Citrix
                   Products.

           2.1.2.  A Combination Product is licensed under a claim of a
                   Microsoft Subject Patent only to the extent that there would
                   not have been infringement (direct or indirect) of such claim
                   by the non-Citrix components of the Combination Product but
                   for the combination of the third party Product with the
                   Citrix Product. The fact that a Combination Product is
                   unlicensed under any claim shall not limit, restrict or
                   otherwise affect the license granted to the Citrix Product
                   included in the Combination Product. Notwithstanding the
                   foregoing, a Combination Product that is a Foundry Product or
                   Clone Product is not licensed under this License.

           2.1.3.  Except to the extent necessary to allow Citrix and its
                   Subsidiaries as described in Section 2.3, to conduct the
                   sale, commercial exploitation, lease, license or other
                   transfer of a Citrix Product, this license does not include a
                   right to grant a sublicense to any of Microsoft's Subject
                   Patents.

           2.1.4.  In the case of those Microsoft Subject Patents licensable
                   hereunder only upon payment of a license fee from Microsoft
                   to a third party, Citrix shall be responsible for payment of
                   such fees, and Citrix' license hereunder 


- ----------------------------
/*/  [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
  AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED.  ALL SUCH OMITTED
  MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
  UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                    - 40 -

                   shall be at Citrix' request and option and subject to payment
                   of such fees and to any other applicable restrictions of the
                   third party licensor.

     2.2.  Citrix to Microsoft

           2.2.1.  Citrix, on behalf of itself and its Subsidiaries,. grants
                   Microsoft a worldwide, nonexclusive, [CONFIDENTIAL TREATMENT
                   REQUESTED]/*/ , non-transferable (except as provided in
                   Section 9) license under any of Citrix' Subject Patents to
                   practice any right under such patents including the right to
                   make, use, sell offer for sale or import, to have made, to
                   commercially exploit, to promulgate any specification related
                   to, to provide any service, or to test any Microsoft
                   Products.

           2.2.2.  A Combination Product is licensed under a claim of a Citrix
                   Subject Patent only to the extent that there would not have
                   been infringement (direct or indirect) by the non-Microsoft
                   component of the Combination Product but for the combination
                   of the third party Product with the Microsoft Product. The
                   fact that a Combination Product is unlicensed under any claim
                   shall not limit, restrict or otherwise affect the license
                   granted to the Microsoft Product included in the Combination
                   Product. Notwithstanding the foregoing, a Combination Product
                   that is a Foundry Product or Clone Product is not licensed
                   under this License.

           2.2.3.  Except to the extent necessary to allow Microsoft and its
                   Subsidiaries as described in Section 2.3, to conduct the
                   sale, commercial exploitation, lease, license or other
                   transfer of a Microsoft Product, this license does not
                   include a right to grant a sublicense to any of Citrix'
                   Subject Patents.

           2.2.4.  In the case of those Citrix Subject Patents licensable
                   hereunder only upon payment of a license fee from Citrix to a
                   third party, Microsoft shall be responsible for payment of
                   such fees, and Microsoft's license hereunder shall be at
                   Microsoft's request and option and subject to payment of such
                   fees and to any other applicable restrictions of the third
                   party licensor.

     2.3.  Subsidiaries: The licenses granted by each Party in Sections 2.1 and
           2.2 shall include the right of the Parties to grant the benefit of
           such licenses to their respective Subsidiaries. To obtain such
           benefit, the Subsidiary shall be bound by the terms and conditions of
           this License as if it were named herein in place of the Parties. If a
           Subsidiary ceases to be a Subsidiary during the term of this License
           and holds any Subject Patents under which a Party hereto has been
           granted a license, such license will continue for the life of such
           Subject Patents. The right to any other licenses shall terminate on
           the date such Subsidiary ceases to be a Subsidiary. The license
           granted to the Subsidiary under Section 2 becomes a limited license
           under the other Party's Subject Patents, issued or issuing from


- ----------------------------
/*/  [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
  AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED.  ALL SUCH OMITTED
  MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
  UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                    - 41 -

           patent applications having a first effective filing date on or before
           the date the Subsidiary ceases to be a Subsidiary, to exercise the
           rights granted in Section 2 with respect to Products identical with
           those Subsidiary Products licensed under Section 2 and commercialized
           (released) prior to the date the Subsidiary ceases to be a
           Subsidiary. All other licenses and rights granted to the Subsidiary
           under this License shall terminate and shall not inure to the benefit
           of the Subsidiary.

3.   RELEASE
     -------

     3.1.  Microsoft to Citrix: Microsoft, on behalf of itself and its
           Subsidiaries, grants to Citrix and its Subsidiaries, including all
           officers, agents and employees (personally and as representatives of
           the company), and their respective customers (including licensees),
           an irrevocable, perpetual release from all claims of infringement of
           any of the rights of Microsoft's Subject Patents, with respect to
           Citrix Products made, used, or sold by Citrix or its Subsidiaries
           before the Effective Date of this License to the extent that such
           Citrix Product would have been the subject of any license hereunder
           had it been made, used, or sold after the Effective Date of this
           License.

     3.2.  Citrix to Microsoft: Citrix, on behalf of itself and its
           Subsidiaries, grants to Microsoft and its Subsidiaries, including all
           officers, agents and employees (personally and as representatives of
           the company), and their respective customers (including licensees),
           an irrevocable, perpetual release from all claims of infringement of
           any of the rights of Citrix' Subject Patents, with respect to
           Microsoft Products made, used, or sold by Microsoft or its
           Subsidiaries before the Effective Date of this License to the extent
           that such Microsoft Product would have been the subject of any
           license hereunder had it been made, used, or sold after the Effective
           Date of this License.

     3.3.  Subsidiary: The term Subsidiary, in this Section 3.1 and 3.2 refers
           only to those Subsidiaries that are Subsidiaries of one of the
           Parties as of the Effective Date. The releases contained in Sections
           3.1 and 3.2 shall not apply to any Person other than those specified
           in this Section 3.

4.   EXCLUSION OF OTHER RIGHTS
     -------------------------

     4.1.  No license is granted herein by or to either Party, with respect to
           any copyrights, mask work rights, trade secrets, know-how,
           trademarks, trade names or similar industrial or intellectual
           property rights. Neither Party is required hereunder to furnish or
           disclose to the other any technical or other information.

     4.2.  Nothing contained in this License shall be construed to confer any
           right to use in advertising, publicity, or other promotional
           activities any trademark or trade name owned by the other Party. Each
           Party agrees not to use or refer to this License or any provision
           thereof in any promotional activity associated with products subject
           to a license hereunder, without express written approval of the other
           Party.


<PAGE>
 
                                    - 42 -


5.   WARRANTY
     --------

     5.1.  Each Party warrants that it has the full right and power to grant the
           license and release set forth in Sections 2 and 3, and that there are
           no outstanding agreements, assignments or encumbrances inconsistent
           with any provisions of this License. Neither Party makes any other
           warranties, express or implied, nor does either Party assume any
           liability with respect to any infringement of patents or other rights
           of third parties owing to the other Party's operation under the
           license granted herein.

     5.2.  Nothing contained in this License shall be construed as a warranty or
           representation by either Party as to the validity or scope of any of
           its Subject Patents.

6.   CONFIDENTIALITY
     ---------------

     The terms of this License shall be kept in confidence by the Parties, and
     shall not be disclosed except as may be required by law. The existence of
     the License will be disclosed only as mutually agreed between the Parties
     in writing. Further, if a specific request for information relevant to this
     License is received from a third party who is a licensee of a Product from
     one Party and who is also threatened with a claim of infringement by the
     other Party, the pertinent terms of Sections 1, 2 and 3 can be disclosed
     after notice is given to the other Party in writing.

7.   TERM AND TERMINATION
     --------------------

     The term of this License shall be from the Effective Date until the
     expiration of the last to expire of the Subject Patents.

8.   LIMITATION OF LIABILITY
     -----------------------

     Neither Party shall be liable for any consequential, incidental, special,
     or punitive damages arising out of or related to this License even if a
     Party has been advised of the possibility of such damages.

9.   ASSIGNMENT AND TRANSFER OF PATENT RIGHTS
     ----------------------------------------

     Any sale or other transfer of, or assignment or grant of any right under, a
     Subject Patent by a Party shall be subject to the rights and licenses
     granted in this License to the other Party. Neither Party shall assign or
     otherwise transfer any of its rights or privileges under this License,
     including the patent licenses granted hereunder, to any third party under
     action of law or otherwise, including without limitation in connection with
     any acquisition of a Party by a third party (including without limitation
     by merger, sale of stock, or otherwise) or in connection with the
     insolvency or bankruptcy of either of the Parties, without the prior
     written consent of the other Party. Any attempted assignment in derogation
     of the foregoing shall be void.


<PAGE>
 
                                    - 43 -


10.   OTHER TERMS
      -----------

      10.1.  No Implied Limitations: Nothing contained in this License shall be
             construed to limit the rights which the Parties have outside the
             scope of the license granted hereunder, or restricting the rights
             of either Party or any of its Subsidiaries to make, have made, use,
             lease, license, sell or otherwise dispose of any particular
             Products not subject to the License.

     10.2.   No Obligation to Obtain or Maintain Patents: No part of this
             License shall be construed to require any Party to file any patent
             application, secure any patent, maintain any patent in force,
             provide copies of patent applications or patents to the other Party
             or disclose any inventions described or claimed in such patents or
             patent applications. However, each Party shall require its
             respective employees, contractors and other persons working for the
             Party, to exclusively assign to the Party the entire right, title
             and interest in and to any patentable inventions that are conceived
             of, developed, or reduced to practice during the period of time
             that the employees or contractors are working for the Party.

     10.3.   No Obligation to Enforce Patents: No part of this License shall be
             construed to require any Party to institute any action or suit
             against third parties for infringement of any of its Subject
             Patents or to defend any action or suit brought by a third party
             challenging or concerning the validity of any of its Subject
             Patents. In addition neither Party shall have any right to
             institute any action or suit against third parties for infringement
             of any of the other Party's Subject Patents.

     10.4.   Notices and Requests: All notices, authorizations, and requests
             required or desired to be given or made in connection with this
             License will be in writing, given by certified or registered mail
             (return receipt requested), express air courier (charges prepaid),
             or facsimile and addressed as follows (or to such other address as
             the Party to receive the notice or request so designates by notice
             to the other):

                        MICROSOFT:
 
                        Microsoft Corporation
                        One Microsoft Way
                        Redmond, Washington 98052-6399
                        Facsimile:(206) 936-7329
                        Attention:  Group Vice President, Platforms
                        Attention: Legal

             With a copy to the same address, Attention: Law and Corporate
             Affairs; Facsimile:(206) 936-7409.



<PAGE>
 
                                    - 44 -
          CITRIX:

          Citrix Systems, Inc.
          6400 NW 6th Way
          Fort Lauderdale, Florida 33309

          Facsimile: President
          Attention: General Counsel

            If a notice is given by either Party by certified or registered
            mail, it will be deemed received by the other Party on the third
            business day following the date on which it is deposited for
            mailing. If a notice is given by either Party by air express
            courier, it will be deemed received by the other Party on the next
            business day following the date on which it is provided to the air
            express courier. If a notice is given by facsimile, it will be
            deemed received by the other Party after confirmation of receipt.

     10.5.  Controlling Law: This License will be construed under and controlled
            by the laws of the State of Washington.

     10.6.  Attorneys' Fees: If Microsoft or Citrix retains outside counsel to
            enforce any rights arising out of or relating to this License, the
            prevailing party will be entitled to recover the reasonable fees,
            costs and other expenses of such counsel from the other party.

     10.7.  Relationship of Parties: This License will not be construed as
            creating a partnership, joint venture or agency relationship, or as
            granting a franchise as defined in the Washington Franchise
            Investment Protection Act, RCW 19. 100, as amended, or 16 CFR
            Section 436.2(a).

     10.8.  Waiver: No waiver of any breach of any provisions of this License
            will constitute a waiver of any prior, concurrent or subsequent
            breach of the same or any other provisions hereof and no waiver will
            be effective unless made in writing and signed by an authorized
            representative of the waiving Party.

     10.9.  Section Headings: The section headings used in this License are
            intended for convenience only and will not be deemed to supersede or
            modify any provisions.

     10.10. Counterparts: This License may be executed in one or more
            counterparts, each of which will be deemed to be an original, but
            all of which together will constitute one and the same instrument.

     10.11. Severability: In the event that any provision contained in this
            license should, for any reason, be held to be invalid or
            unenforceable in any respect under the laws of any state or of the
            United States, the Parties shall negotiate in good faith to revise


<PAGE>
 
                                    - 45 -

            the terms of this License in order to adjust for the invalidity or
            unenforceability of such provision.

     10.12. Entire Agreement: This License does not constitute an offer by
            either Party and will not be effective until signed by both Parties.
            Upon execution by both Parties, this License will constitute the
            entire agreement between the Parties with respect to the subject
            matter hereof and merges all prior and contemporaneous
            communications. It will not be modified except by a written
            agreement signed on behalf of the Parties by their respective duly
            authorized representatives. Unless agreed to in a separate writing
            signed by both Parties, any statement appearing as a restrictive
            endorsement on a check or other document which purports to modify a
            right, obligation or liability of either Party will be of no force
            and effect.

IN WITNESS OF, the Parties hereto have caused this License to be signed so as to
be effective as of the effective date set forth above.


MICROSOFT CORPORATION


By:  /s/  Paul Maritz
   -------------------------

Title:  Group Vice President
      ----------------------

Date:  May 9, 1997
     -----------------------


CITRIX SYSTEMS, INC.

By:  /s/  Edward E. Iacobucci
   --------------------------

Title:  Chairman
      -----------------------

Date:  May 9, 1997
     ------------------------


<PAGE>
 
                                    - 46 -

                                   Exhibit G

                             Hydrix Product Support
                             ----------------------

The Technical Coordinators acknowledge that the optimal support structure will
be different for Hydrix 4.0 and Hydrix 5.0. The Technical Coordinators will
prepare a support plan for each Hydrix release and present such plan for
acceptance by the Named Executives as a revised Exhibit G to this Agreement.

In general, Citrix will provide technical bug-fix support to Microsoft for
Hydrix 4.0 and responses to priority requests for problem assistance with regard
to unmodified portions of Hydrix shall be provided within the following
escalation guidelines:

Priority 1:  [CONFIDENTIAL TREATMENT REQUESTED]/*/
- ----------                                        

Priority 2:  [CONFIDENTIAL TREATMENT REQUESTED]/*/
- ----------                                        

Priority 3:  [CONFIDENTIAL TREATMENT REQUESTED]/*/
- ----------                                        

- ----------------------------
/*/  [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
  AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED.  ALL SUCH OMITTED
  MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
  UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.
<PAGE>
 
                                    - 47 -

                                   Exhibit H
                                   ---------


Designated Companies
[CONFIDENTIAL TREATMENT REQUESTED]/*/

- ---------------------------
/*/ [CONFIDENTIAL TREATMENT REQUESTED] INDICATES MATERIAL THAT HAS BEEN OMITTED
AND FOR WHICH CONFIDENTIAL TREATMENT HAS BEEN REQUESTED.  ALL SUCH OMITTED
MATERIAL HAS BEEN FILED WITH THE COMMISSION PURSUANT TO RULE 24b-2 PROMULGATED
UNDER THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED.

<PAGE>

                                                                      EXHIBIT 99

MICROSOFT AND CITRIX SIGN TECHNOLOGY CROSS-LICENSING AND DEVELOPMENT AGREEMENT


REDMOND, Wash., May 12 /PRNewswire/ -- Microsoft Corp. (Nasdaq:  MSFT) today
announced a joint development agreement with Citrix Systems Inc. (Nasdaq:  CTXS)
to provide Windows(R)-based terminal support for the Microsoft(R) Windows NT(R)
Server network operating system.  Under the agreement, Microsoft will license
Citrix multiuser technology and the companies will cooperate on the development
of advanced multiuser capabilities for both Windows NT Server 4.0 generation
servers and Windows NT Server 5.0 generation servers.  These advanced multiuser
capabilities allow applications to be executed from the server and support the
concept of "Windows-based terminals."

A Windows-based terminal is a true "thin client" that launches and runs Windows
NT-based applications from the server.  These Windows-based terminals can be
used by task-based workers who only need a limited-function device on their
desktop.  The Windows-based terminal is 100 percent Windows-compatible across a
full range of solutions.  This means customers will be able to deploy a
combination of Windows-based terminals, NetPCs and PCs, depending upon user
requirements, and will know that their applications will run across all types of
Windows-based systems.  The Windows-based terminal completes the broad range of
Windows family solutions, from handheld PCs running Windows CE to NetPCs to PCs
to high-end Windows NT Workstation-based systems.

"Customers have told us that reducing total cost of ownership is a critical
issue," said Paul Maritz, group vice president of platform and applications at
Microsoft.  "We are evolving the Windows platform with key hardware and software
initiatives to aggressively address this fundamental issue for our customers."

With Microsoft's Zero Administration for Windows initiative, businesses can
reduce the cost of managing users, software and hardware.  In addition,
Microsoft is addressing the fundamental cost of computing hardware by endorsing
two new corporate Windows-based devices, the NetPC and the Windows-based
terminal.  The NetPC is a redefined personal computer providing all of the power
of a normal PC while providing hardware-related management features, such as a
sealed case, to reduce end-user support costs.  The Windows-based terminal will
round out the Windows product family, providing the "thinnest" and most
manageable of the Windows-based clients and will provide the lowest cost of
ownership.  The Zero Administration initiative improvements will apply to all PC
devices, not just these two new members of the hardware family.

Microsoft and Citrix will cooperate on the development of base multiuser
capabilities.  These base capabilities will be marketed by Microsoft as part of
its Windows NT Server 4.0 and 5.0 generations of server products.  Citrix and
Microsoft will each develop and market additional components, built upon these
base services, to support their ICA and T.Share protocols, respectively.  These
protocols are used to remotely display the user interface of applications
running on the server on the client device.  Microsoft will support the T.Share
protocol, which is currently used in products such as NetMeeting(TM)
conferencing software, for support of clients 
<PAGE>
 
                                      -2-

running Windows-family operating systems such as Windows CE. ICA is the protocol
that has been developed by Citrix, and will be the preferred protocol for
heterogeneous devices and clients. The Citrix environment will include full
support for features and functions currently supported by its existing WinFrame
servers, and Citrix will continue to provide support to its customer base.

Citrix is a leader in multiuser Windows-based application server software with
an installed base of more than 500,000 concurrent user connections to its
WinFrame servers.  WinFrame is a proven solution for thousands of organizations
across a broad range of industries worldwide.

"This is the next logical step in the close relationship we've enjoyed with
Microsoft since Citrix was founded over eight years ago," said Edward Iacobucci,
Citrix chairman and chief technical officer.  "This joint development agreement
will result in a Windows NT Server platform on which we can continue to address
growing customer demand for innovative thin client solutions through our
Independent Computing Architecture."

Microsoft also announced today an agreement with Prologue Software to license
its multiuser technology and for Prologue to cooperate in the development and
deployment of multiuser capabilities for Windows NT Server.  Prologue engineers
will cooperate to further enhance these efforts.  Prologue Software, a leading
supplier of multiuser operating systems in Europe, has more than 20 years
experience in multiuser operating systems and more than four years experience
developing terminal support for Windows NT Server.

"Prologue Software looks forward to helping Microsoft produce a great product
and assisting its customers in the deployment of Windows-based terminals," said
Georges Seban, chairman of the board and president at Prologue Software.
"Prologue Software plans to provide Windows NT-based multiuser administration
tools along with consulting and training services for Windows NT Server
multiuser solutions."

Citrix's Windows NT Server-based WinFrame enterprise software will continue to
be available for customers deploying solutions today and Citrix will offer a
smooth migration to the future Windows NT Server-based multiuser solutions.
More details on the product availability and beta test time line will be
announced in the future.  Information for Windows NT Server can be found at
http://www.microsoft.com/ntserver.
- ----------------------------------

Founded in 1975, Microsoft (Nasdaq "MSFT") is the worldwide leader in software
for personal computers.  The company offers a wide range of products and
services for business and personal use, each designed with the mission of making
it easier and more enjoyable for people to take advantage of the full power of
personal computing every day.

Founded in 1989, Citrix Systems Inc. is a leader in multiuser application server
software, developed under license and strategic agreement with Microsoft.  The
company's flagship WinFrame product line is marketed through a worldwide
business alliance of value-added resellers, system integrators, OEM licensees
and industry partners.  Citrix is based in Fort Lauderdale, Fla., and is traded
on the Nasdaq stock exchange under the symbol CTXS.
<PAGE>
 
                                      -3-

Forward-looking statements in this release are made pursuant to the safe harbor
provisions of the Private Securities Litigation Reform Act of 1995.  Investors
are cautioned that statements in this press release which are not strictly
historical statements, including, without limitation, statements regarding
management's plans and objectives for future operations, product plans and
performance, management's assessment of market factors, as well as statements
regarding the strategy and plans of the Company and its strategic partners,
constitute forward-looking statements which involve risks and uncertainties,
including, without limitation, risks associated with the Company's reliance upon
its strategic relationships with Microsoft and other strategic partners,
dependence upon broad-based acceptance of the Company's ICA protocol, management
of growth, the possibility of undetected software errors, and dependence on
proprietary technology, as well as risks of downturns in economic conditions
generally, and in the software industry specifically, risks associated with
competition and competitive pricing pressures, and other risks detailed in the
Company's filings with the Securities and Exchange Commission.

Microsoft, Windows, Windows NT and NetMeeting are either registered trademarks
or trademarks of Microsoft Corp. in the United States and/or other countries.

Other product and company names herein may be trademarks of their respective
owners.

Copyright 1997, PR Newswire


© 2022 IncJournal is not affiliated with or endorsed by the U.S. Securities and Exchange Commission