<PAGE>
                                                                    EXHIBIT 2.1
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                               ASSET PURCHASE AGREEMENT



                                    BY AND BETWEEN



                                KLA-TENCOR CORPORATION

                                         AND

                                  OBJECTSPACE, INC.









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                                                                    EXHIBIT 2.1

                                  TABLE OF CONTENTS

<TABLE>
<CAPTION>
<S>                                                                                 <C>
Section                                                                             Page
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1.     TRANSFER OF ASSETS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   1

     (a)  Personal Property. . . . . . . . . . . . . . . . . . . . . . . . . . . . .   1

     (b)  Intellectual Property. . . . . . . . . . . . . . . . . . . . . . . . . . .   1

     (c)  Contracts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2

     (d)  Prepaid Assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2

     (e)  Marketing and Sales Information. . . . . . . . . . . . . . . . . . . . . .   2

     (f)  Documents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2

     (g)  Licenses and Permits . . . . . . . . . . . . . . . . . . . . . . . . . . .   2

2.     ASSETS EXCLUDED FROM SALE . . . . . . . . . . . . . . . . . . . . . . . . . .   2

3.     PURCHASE PRICE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4

     (a)  Amount of Purchase Price . . . . . . . . . . . . . . . . . . . . . . . . .   4

     (b)  Manner of Payment of the Purchase Price. . . . . . . . . . . . . . . . . .   4

     (c)  Allocation of Purchase Price . . . . . . . . . . . . . . . . . . . . . . .   4

4.     ASSUMPTION OF LIABILITIES . . . . . . . . . . . . . . . . . . . . . . . . . .   4

     (a)  Generally. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4

     (b)  Excluded Liabilities . . . . . . . . . . . . . . . . . . . . . . . . . . .   5

     (c)  Limitations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   7

5.     LABOR AND EMPLOYMENT MATTERS. . . . . . . . . . . . . . . . . . . . . . . . .   7

     (a)  Employment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   7

     (b)  Employment Transition Provisions . . . . . . . . . . . . . . . . . . . . .   8

     (c)  Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   9

6.     CLOSING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   9

     (a)  Location and Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . .   9

     (b)  Costs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   9

     (c)  Seller's Closing Documents . . . . . . . . . . . . . . . . . . . . . . . .   9

     (d)  Purchaser's Closing Documents. . . . . . . . . . . . . . . . . . . . . . .  10

     (e)  Further Assurances . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11

     (f)  Prorations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  12

     (g)   Purchase Price Escrow . . . . . . . . . . . . . . . . . . . . . . . . . .  12


                                             i
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                                                                               EXHIBIT 2.1

     (h)  Working Capital Adjustment . . . . . . . . . . . . . . . . . . . . . . . .  12

     (i)  Employee Retention Funds . . . . . . . . . . . . . . . . . . . . . . . . .  14

7.     REPRESENTATIONS AND WARRANTIES OF SELLER. . . . . . . . . . . . . . . . . . .  14

     (a)  Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14

     (b)  Authorization of Agreement . . . . . . . . . . . . . . . . . . . . . . . .  14

     (c)  Business Financial Statements. . . . . . . . . . . . . . . . . . . . . . .  15

     (d)  Tax Matters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  15

     (e)  Actions, Suits, Proceedings. . . . . . . . . . . . . . . . . . . . . . . .  16

     (f)  Compliance with Applicable Laws and Other Instruments. . . . . . . . . . .  16

     (g)  Facility Lease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  16

     (h)  Title to the Purchased Assets. . . . . . . . . . . . . . . . . . . . . . .  16

     (i)  Intellectual Property Rights . . . . . . . . . . . . . . . . . . . . . . .  17

     (j)  Contracts, Leases, Commitments and Agreements. . . . . . . . . . . . . . .  17

     (k)  Composition and Condition of Purchased Assets. . . . . . . . . . . . . . .  18

     (l)  Insurance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  18

     (m)  Major Suppliers and Customers. . . . . . . . . . . . . . . . . . . . . . .  18

     (n)  Employee Plans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  18

     (o)  Labor Matters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19

     (p)  Government License and Regulation. . . . . . . . . . . . . . . . . . . . .  19

     (q)  Location of the Assets . . . . . . . . . . . . . . . . . . . . . . . . . .  19

     (r)  Year 2000. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19

8.     REPRESENTATIONS AND WARRANTIES OF PURCHASER . . . . . . . . . . . . . . . . .  19

     (a)  Corporate Organization . . . . . . . . . . . . . . . . . . . . . . . . . .  20

     (b)  Corporate Authority. . . . . . . . . . . . . . . . . . . . . . . . . . . .  20

     (c)  Litigation and Other Proceedings . . . . . . . . . . . . . . . . . . . . .  20

9.   CONDITIONS TO OBLIGATION OF PURCHASER TO CLOSE. . . . . . . . . . . . . . . . .  20

     (a)  Representations and Warranties . . . . . . . . . . . . . . . . . . . . . .  20

     (b)  Observance and Performance . . . . . . . . . . . . . . . . . . . . . . . .  21

     (c)  Violations of Laws and Ordinances. . . . . . . . . . . . . . . . . . . . .  21

     (d)  Officer's Certificate. . . . . . . . . . . . . . . . . . . . . . . . . . .  21

     (e)  Change in Assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  21


                                            ii
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                                                                             EXHIBIT 2.1

     (f)  Key Employees. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  21

     (g)  Searches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  21

     (h)  Consents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  21

     (i)  Closing Documents. . . . . . . . . . . . . . . . . . . . . . . . . . . . .  22

     (j)  Proceedings and Documents. . . . . . . . . . . . . . . . . . . . . . . . .  22

     (k)  Hiring of Employees. . . . . . . . . . . . . . . . . . . . . . . . . . . .  22

10.    CONDITIONS TO OBLIGATION OF SELLER TO CLOSE . . . . . . . . . . . . . . . . .  22

     (a)  Representations and Warranties . . . . . . . . . . . . . . . . . . . . . .  22

     (b)  Observance and Performance . . . . . . . . . . . . . . . . . . . . . . . .  22

     (c)  Violations of Laws and Ordinances. . . . . . . . . . . . . . . . . . . . .  22

     (d)  Officer's Certificate. . . . . . . . . . . . . . . . . . . . . . . . . . .  22

     (e)  Closing Documents. . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23

     (f)  Proceedings and Documents. . . . . . . . . . . . . . . . . . . . . . . . .  23

     (g)  Purchase Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23

11.    GOVERNMENTAL FILINGS. . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23

12.    COVENANTS OF SELLER . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23

     (a)  Operation of Business Prior to Closing . . . . . . . . . . . . . . . . . .  23

     (b)  Notices to Employees; Continuation of Benefits . . . . . . . . . . . . . .  24

     (c)  Access and Information . . . . . . . . . . . . . . . . . . . . . . . . . .  24

     (d)  Public Announcements . . . . . . . . . . . . . . . . . . . . . . . . . . .  25

     (e)  Notice of Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . .  25

     (f)  Transfer Taxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  25

     (g)  No Solicitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  25

     (h)  Further Actions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  26

     (i)  Covenant not to Sue. . . . . . . . . . . . . . . . . . . . . . . . . . . .  26

13.    COVENANT NOT TO COMPETE . . . . . . . . . . . . . . . . . . . . . . . . . . .  26

14.    COVENANTS OF PURCHASER. . . . . . . . . . . . . . . . . . . . . . . . . . . .  27

     (a)  Public Announcements . . . . . . . . . . . . . . . . . . . . . . . . . . .  27

     (b)  Notice of Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  27

     (c)  Further Actions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  27

     (d)  Use of Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  27


                                           iii
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                                                                             EXHIBIT 2.1

15.    INDEMNIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  27

     (a)  Survival of Representations and Warranties . . . . . . . . . . . . . . . .  28

     (b)  Indemnification by Seller. . . . . . . . . . . . . . . . . . . . . . . . .  28

     (c)  Indemnification by Purchaser . . . . . . . . . . . . . . . . . . . . . . .  29

     (d)  Procedures for Indemnification . . . . . . . . . . . . . . . . . . . . . .  29

     (e)  Sole Remedy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  30

16.    TERMINATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  30

17.    DISPUTE RESOLUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  32

     (a)  Arbitration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  32

     (b)  Discovery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  32

     (c)  Court Proceedings. . . . . . . . . . . . . . . . . . . . . . . . . . . . .  32

     (d)  Rulings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  33

     (e)  Findings of Fact . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  33

     (f)  Authority. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  33

     (g)  Equitable Remedies . . . . . . . . . . . . . . . . . . . . . . . . . . . .  33

     (h)  Selection of Arbitrator. . . . . . . . . . . . . . . . . . . . . . . . . .  33

     (i)  Other Arbitration Provisions . . . . . . . . . . . . . . . . . . . . . . .  34

18.    ADDITIONAL AGREEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . .  34

     (a)  Confidential Information . . . . . . . . . . . . . . . . . . . . . . . . .  34

     (b)  Transition Services. . . . . . . . . . . . . . . . . . . . . . . . . . . .  35

19.    MISCELLANEOUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  35

     (a)  Amendments and Waiver. . . . . . . . . . . . . . . . . . . . . . . . . . .  35

     (b)  Governing Law. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  36

     (c)  Notices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  36

     (d)  Benefit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  37

     (e)  Entire Agreement . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  37

     (f)  Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  37

     (g)  Brokers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  37

     (h)  Disclosure Schedule. . . . . . . . . . . . . . . . . . . . . . . . . . . .  37

     (i)  Counterparts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  37
</TABLE>

                                            iv
<PAGE>

                                                                    EXHIBIT 2.1

                              ASSET PURCHASE AGREEMENT


     THIS ASSET PURCHASE AGREEMENT (the "AGREEMENT") is made and entered into as
of this 8th  day of March, 2000 by and between KLA-Tencor Corporation, a
Delaware corporation ("PURCHASER"), and OBJECTSPACE, INC., a Delaware
corporation ("SELLER").

                                       RECITALS

     A.   Seller is engaged, among other things, in the business of providing
software products and services in the area of electronics manufacturing yield
and productivity improvement through development, application, and support of
factory monitoring and control software solutions (collectively, the
"BUSINESS").

     B.   Seller desires to sell to Purchaser and Purchaser desires to purchase
and acquire from Seller the Purchased Assets (as hereinafter defined) relating
to the Business and Purchaser desires to assume, as part of the purchase price
of the Purchased Assets, the Assumed Liabilities (as hereinafter defined) as of
the Closing Date (as hereinafter defined), all upon the terms and conditions set
forth herein.

                                      AGREEMENTS

     NOW, THEREFORE, in consideration of the foregoing recitals and the mutual
covenants and agreements contained herein, the parties agree as follows:

     1.   TRANSFER OF ASSETS.  On the terms and subject to the conditions of
this Agreement, Seller agrees to sell, transfer, convey, deliver and assign to
Purchaser, and Purchaser agrees to purchase, acquire and accept from Seller, at
and effective as of the Closing Date, for the consideration hereinafter
provided, all of Seller's rights, title and interest in and to the following
assets, properties and rights in and related to the Business, other than the
Excluded Assets (as hereinafter defined) (the "PURCHASED ASSETS"):

          (a)  PERSONAL PROPERTY.  All machinery, equipment, computer hardware,
     cabling, data viewers, improvements, tools, furniture, furnishings and
     other tangible personal property listed on SCHEDULE 1(A) hereto.

          (b)  INTELLECTUAL PROPERTY.  All of Seller's rights in the trademarks,
     trade secrets, copyrights (including those in software), patents, pending
     patent applications, and other intellectual property, and all associated
     goodwill, and all related applications and registrations for the foregoing
     (collectively, the "INTELLECTUAL PROPERTY") that are listed on
     SCHEDULE 1(b) attached hereto.

<PAGE>

                                                                    EXHIBIT 2.1

          (c)  CONTRACTS.  To the extent the consents listed on the Disclosure
     Schedule to Section 7(j) have been obtained, all rights of Seller under the
     contracts, agreements, personal property leases, licenses, purchase orders,
     sales orders and other instruments, agreements and arrangements that are
     listed on SCHEDULE 1(c) (hereinafter collectively referred to as the
     "ASSUMED CONTRACTS").

          (d)  PREPAID ASSETS.  All deposits or other prepaid items relating to
     services or products provided by the Business and accepted by Seller prior
     to the Closing (as hereinafter defined) but to be delivered by Purchaser on
     or subsequent to the Closing that are listed on SCHEDULE 1(d), as such may
     be amended by mutual agreement of the parties up to the Closing.

          (e)  MARKETING AND SALES INFORMATION.  All customer lists, vendor or
     supplier lists, prospect lists, database information, marketing or
     advertising brochures or pamphlets, documents, records or other
     information, whether in electronic form or otherwise, owned by Seller and
     relating to current or planned sales or marketing operations of the
     Business.

          (f)  DOCUMENTS.  All copies of records, computer software and
     documents, books, work orders, drawings, electronic art, database
     information, program and process documentation owned by Seller and
     primarily related to the Business.

          (g)  LICENSES AND PERMITS.  To the extent transferable, all of
     Seller's rights in all government licenses, permits and authorizations
     listed on SCHEDULE 1(g) hereto.

     2.   ASSETS EXCLUDED FROM SALE.  Notwithstanding other contrary provisions
of this Agreement, the following property and assets of Seller are expressly
excluded from the sale to Purchaser (the "EXCLUDED ASSETS"):

          (a)  Any employee benefit plan (within the meaning of Section 3(3) of
     the Employee Retirement Income Security Act of 1974 ("ERISA")) with respect
     to which Seller or any entity which, together with Seller, would be deemed
     a "single employer" (within the meaning of Sections 414(b), (c), (m) or (o)
     of the Internal Revenue Code of 1986, as amended (the "CODE")) is a plan
     sponsor or would otherwise have any potential liability.

          (b)  Any of Seller's causes of action, judgments, claims and demands
     of whatever nature, except those related to the Purchased Assets and the
     Assumed Liabilities.

          (c)  Articles of Incorporation, Bylaws, corporate seal and original
     minute books of Seller (it being agreed that copies of those minutes
     relating to the sale of the Business shall be supplied to Purchaser before
     the Closing), qualifications to conduct business as a foreign corporation,
     taxpayer and other identification numbers and other documents relating to
     the organization, maintenance and existence of Seller as a corporation.


                                       2
<PAGE>

                                                                    EXHIBIT 2.1

          (d)  All financial records of Seller relating to the Business,
     including Seller's general ledger and related items, tax returns and
     related work papers (it being agreed that copies of those financial records
     relating to the Business shall be supplied to Purchaser before the
     Closing).

          (e)  All of Seller's cash (including cash received after the Closing
     for products or services relating to the Business delivered on or before
     the Closing) and cash equivalents, including all deposits and other prepaid
     items not described in Section 1(d) of this Agreement.

          (f)  All rights of Seller under this Agreement and all other related
     agreements to which Seller is a party contemplated by this Agreement.

          (g)  All of Seller's personnel records and other records that Seller
     is required by law to retain in its possession and all invoices, expense
     reports and purchase orders.

          (h)  All of Seller's claims for refunds of Taxes and other
     governmental charges of whatever nature relating to periods prior to the
     Closing Date.

          (i)  Other than the licensed software located on the personal
     computers used by the Scheduled Employees, all of Seller's enterprise-wide
     licensed software including, without limitation, Lotus/Notes software used
     for artifact management, server software that connects the Austin IT
     infrastructure of the Business to Seller's Dallas office, and corporate
     financial systems.

          (j)  All of Seller's rights in insurance policies and insurance
     claims.

          (k)  All trademarks, trade names, service marks and other intellectual
     property relating to or including the name "ObjectSpace" and "Voyager," and
     all derivations thereof, and all intellectual property relating to Seller's
     Voyager Software and C++ toolkit (Standards Toolkit; Foundations Toolkit;
     Communications Toolkit; Systems Toolkit).

          (k)  All rights of Seller in the T1 line used in the Business to
     connect the Business to Seller's Dallas headquarters.

          (m)  All of Seller's rights in its Dallas server, which is currently
               used to host the Web site relating to the Business.

          (n)  All assets listed on Schedule 2(n) hereto.


                                       3
<PAGE>

                                                                    EXHIBIT 2.1

     3.   PURCHASE PRICE.

          (a)  AMOUNT OF PURCHASE PRICE.  In addition to the assumption of the
     Assumed Liabilities (as hereinafter defined) by Purchaser, Purchaser shall
     pay to Seller for the Purchased Assets an amount equal to $8,000,000 (the
     "PURCHASE PRICE"), including the $800,000 which shall be held in an escrow
     account pursuant to Section 6(g), and subject to adjustment as set forth in
     Section 6(h).  The Purchase Price will be exclusive of all Transfer Taxes
     (as hereinafter defined).  All references to "$" and "dollars" herein shall
     mean United States dollars.

          (b)  MANNER OF PAYMENT OF THE PURCHASE PRICE.  At the Closing,
     Purchaser shall assume the Assumed Liabilities and deliver $6,930,000 (the
     Purchase Price minus the Purchase Price Escrow Funds (defined below) and
     the Employee Retention Funds (defined below)) (the "CASH PURCHASE PRICE")
     by wire transfer of immediately available funds to Seller.

          (c)  ALLOCATION OF PURCHASE PRICE.  The parties agree to allocate the
     aggregate of the Purchase Price and the Assumed Liabilities to the
     Purchased Assets and to the covenants not to compete of Seller as set forth
     on SCHEDULE 3(c) hereto which shall comply with Section 1060 of the Code.
     Seller and Purchaser agree that they will adopt and utilize the amounts
     allocated to each Purchased Asset and such other assets and benefits for
     purposes of all Tax Returns (as hereinafter defined) filed by them and that
     they will not voluntarily take any position inconsistent therewith.
     Purchaser agrees to prepare and timely file all applicable Internal Revenue
     Service and other governmental authority forms, and each party hereto
     agrees to cooperate with the other party's reasonable request in the
     preparation of such forms, and to furnish the other party with a copy of
     such forms prepared in draft, within a reasonable period before the filing
     due date thereof.

     4.   ASSUMPTION OF LIABILITIES.

          (a)  GENERALLY.  On the Closing Date, as partial consideration for the
     purchase of the Purchased Assets, Purchaser shall assume and agree to pay,
     perform and discharge, to the extent not theretofore performed, paid or
     discharged, the following (and only the following) liabilities and/or
     obligations of Seller relating to the Business (collectively, the "ASSUMED
     LIABILITIES"):

               (1)  FACILITY LEASE.  The Office Lease between Steve R. Scott and
          Seller dated June 9, 1997, as amended (the "FACILITY LEASE"), relating
          to the facility located at 811 Barton Springs Road, Suite 300, Austin,
          Texas 78704-1163 (the "FACILITY").

               (2)  ASSUMED CONTRACTS.  The obligations of Seller under the
          Assumed Contracts.


                                       4
<PAGE>

                                                                    EXHIBIT 2.1

               (3)  PRORATED ITEMS.  The pro rated amounts determined pursuant
          to Section 6(f) of this Agreement.

               (4)  TAXES. Any and all liabilities and obligations, direct or
          indirect, fixed or contingent, for Taxes attributable to and incurred
          in connection with the Business or the Purchase Assets after the
          Closing Date, including, without limitation, any AD VALOREM, real or
          personal or intangible property, sales or other Taxes which are
          attributable to any period after the Closing Date.

               (5)  EMPLOYEE LIABILITIES. All (i) accrued payroll taxes
          attributable to the Scheduled Employees on the Closing Date, (ii) all
          accrued liabilities owed to the Scheduled Employees on the Closing
          Date, including accrued vacation benefits, sick leave benefits,
          bonuses, and commissions and (iii) those liabilities set forth on
          SCHEDULE 4(a)(5) related to other employee benefits for the Scheduled
          Employees.

          (b)  EXCLUDED LIABILITIES.  Except for the liabilities and
     obligations of Seller expressly assumed by Purchaser under Section 4(a)
     hereof, Purchaser shall not assume, and the term "Assumed Liabilities"
     shall not include, any liabilities or obligations of Seller
     (collectively, the "EXCLUDED LIABILITIES"), including, without
     limitation, the following, and Seller expressly agrees it will remain
     liable for, it will indemnify Purchaser, its stockholders, affiliates,
     employees, agents and representatives for, and it will discharge, the
     Excluded Liabilities:

               (1)  Any liability or claim with respect to accidents or
          occurrences arising on or before the Closing Date.

               (2)  Any claim by a third party for personal injury, injury or
          damage to property or economic loss, whether sounding in tort, breach
          of warranty or any other theory of recovery, seeking compensatory,
          special, exemplary, punitive or consequential damages, or any other
          relief, relating, directly or indirectly, to an alleged defective or
          unsuitable product arising prior to the Closing Date.

               (3)  Any claims (including severance claims) relating to the
          termination by Seller of the employment of any of its employees
          (including any such termination deemed to have occurred upon the
          transfer of any such employee from Seller to Purchaser).

               (4)  Except as set forth in Section 4(a), any unpaid liability
          for Taxes (as hereinafter defined) incurred prior to the Closing
          Date, including without limitation the following:  any and all
          liabilities and obligations, direct or indirect, fixed or
          contingent, for Taxes (i) of Seller or any member of any affiliated
          group (within the

                                      5

<PAGE>

                                                                    EXHIBIT 2.1

          meaning of Section 1504(a) of the Code) or any combined, consolidated
          or unitary group for state or other tax purposes of which Seller is
          or has been a member, whenever incurred; (ii) except as expressly
          set forth herein, attributable to or incurred in connection with the
          Business or the Purchased Assets prior to or on the Closing Date,
          including, without limitation, any AD VALOREM, real or personal or
          intangible property, sales or other Taxes which are not due or
          assessed until after the Closing Date but which are attributable to
          any period (or portion thereof) ending on the Closing Date and (iii)
          attributable to interest, fines, additions to tax or penalties
          relating to Taxes. For purposes of this Agreement, (A) the term
          "TAXES" shall mean any and all taxes, duties, premiums, imposts,
          charges, fees, levies, excises, deductions, withholdings or other
          like assessments (and all related interest, fines, additions to tax
          and penalties), including, without limitation, those levied on, or
          measured by, or referred to as income, transfer, gains, gross
          receipts, profits, capital, excise, inventory, property (real,
          personal or intangible), land transfer, value-added, goods and
          services, sales, use, license, withholding, payroll, health,
          employment, stamp, business, capital stock, franchise, social
          services, education and social security taxes, all surtaxes, all
          customs duties and import and export taxes, all license, franchise
          and registration fees and all unemployment insurance, health
          insurance and other government pension plan premiums, imposed by the
          United States or any state, local or foreign government or
          subdivision or agency thereof, whether computed on a consolidated,
          unitary, combined or any other basis; and (B) the term "TAX RETURNS"
          shall mean any and all reports, returns or other information filed
          with or required to be supplied to a taxing authority in connection
          with Taxes.

               (5)  Any cause of action or judicial or administrative action,
          suit, proceeding or investigation relating to periods prior to the
          Closing.

               (6)  Any governmental compliance, enforcement or regulatory
          action, suit or claim or any claim by any person or entity based upon
          an actual or alleged failure of Seller to comply prior to the Closing
          with, or an actual or alleged violation by Seller prior to the
          Closing of, any law, rule, regulation, statute, ordinance, permit,
          permit requirement, judgment, injunction, order, decree, license or
          other governmental authorization or approval applicable to Seller or
          the Purchased Assets.

               (7)  Any infringement of the rights of any other person or
          entity arising out of the use of any of the Purchased Assets prior to
          the Closing.

               (8)  Except as set forth in Section 4(a), any liability under
          any employee benefit plan maintained or contributed to by Seller or
          any ERISA Affiliate (as hereinafter defined) which is not assumed by,
          or plan assets are not transferred to, the Purchaser.

                                      6

<PAGE>

                                                                    EXHIBIT 2.1

               (9)  Any liabilities with respect to contracts of Seller (other
          than the Assumed Contracts).

               (10) Any liabilities or obligations of Seller relating to
          casualty or liability claims attributable to the period prior to the
          Closing.

               (11) Bank overdrafts and other liabilities of Seller to banks
          for money borrowed.

               (12) Any and all other liabilities and/or obligations of Seller
          not specifically included in the Assumed Liabilities.

          (c)  LIMITATIONS.  The parties expressly agree (1) that the only
     liabilities and obligations of Seller which Purchaser has agreed to pay or
     assume are the Assumed Liabilities and (2) that Purchaser has not agreed
     to pay, shall not be required to assume and shall not have any liability
     or obligation, direct or indirect, absolute or contingent, of Seller, the
     Business, or any other person or entity, the assumption of which by
     Purchaser is not expressly provided for in this Agreement as an Assumed
     Liability.

     5.   LABOR AND EMPLOYMENT MATTERS.

          (a)  EMPLOYMENT.  Attached hereto as SCHEDULE 5(a) is a list of all
     active employees of the Business, on the payroll and available for duty on
     the Closing Date (the "SCHEDULED EMPLOYEES"). Purchaser agrees to offer
     employment, effective from the Closing, to all of the Scheduled Employees.
     In addition, Purchaser agrees to provide Scheduled Employees with group
     health insurance benefits immediately after Closing and to waive, and to
     cause its appropriate insurer to waive, any pre-existing illness
     limitations. Purchaser agrees to provide each Scheduled Employee with past
     service credit for the period of time that the Scheduled Employee has been
     employed by Seller under Purchaser's group health plan and Purchaser's
     401(k) plan and/or any other defined contribution or defined benefit
     pension plan maintained by the Purchaser. Subject to the foregoing two
     sentences, Purchaser agrees to provide the Scheduled Employees with
     medical, dental, 401(k) retirement and other benefits in accordance with
     Purchaser's standard employee benefit plans.

          (b)  EMPLOYMENT TRANSITION PROVISIONS. (i) Seller shall furnish its
     employees, their representatives and appropriate governmental authorities
     such notice as may be required of Seller by and in accordance with
     applicable laws and regulations, including, without limitation, any mass
     lay-off laws for events that occur prior to Closing which require such
     notices; Purchaser shall be responsible for all such notices for events
     which occur on or after Closing. Seller shall be solely responsible for
     providing continuation coverage under the Consolidated Omnibus Budget
     Reconciliation Act of 1985, as amended ("COBRA") to

                                      7

<PAGE>

                                                                    EXHIBIT 2.1

     Scheduled Employees and their dependents who are qualified beneficiaries
     (as defined in Section 4980B(g)(1) of the Code) and Seller shall
     indemnify Purchaser for any and all loss, cost, or expense relating to
     any and all outstanding obligations, liabilities and claims arising under
     COBRA and relating to Seller's employment of Scheduled Employees. Each
     person employed by Seller in the Business and to be employed after the
     Closing by Purchaser in accordance with Section 5(a) hereof shall cease
     to be an employee of Seller effective immediately following the Closing.
     In addition, except for those items set forth in Section 4(a) hereof,
     Seller shall pay or provide for all other employee benefits maintained by
     Seller for all periods prior to and including the Closing Date, all in
     accordance with applicable law.

          (ii) Purchaser and Seller agree to use their commercially reasonable
     efforts to enable the Scheduled Employees to transfer their aggregate
     account balances from Seller's 401(k) plan to Purchaser's 401(k) plan.
     Seller shall amend its 401(k) plan to transfer an amount equal to the
     account balances of the Scheduled Employees in the Seller's 401(k) plan
     valued at the most recent valuation date preceding the date the transfer
     is made to Buyer's 401(k) plan. The transfer will be accomplished by way
     of a single transfer of plan assets, except that any outstanding
     participant loans from the Seller's 401(k) plan to Scheduled Employees
     that are not in default may be transferred in kind to the extent not
     repaid prior to the transfer. Seller and Purchaser agree to cooperate
     fully and to file in a timely manner whatever reports, forms, and notices
     (including, without limitation, Form 5310-A) as necessary or appropriate
     under applicable law as a result of, and to effect, the transfer. Seller
     agrees to provide to Purchaser in a timely manner all information and
     documentation concerning its 401(k) plan that Purchaser reasonably
     requests in order to ensure that Seller's 401(k) plan and the transfer
     described herein are in compliance with applicable law, including without
     limitation ERISA and the Code. Seller also agrees to provide to Purchaser
     in a timely manner all information for each Scheduled Employee, including
     without limitation the account balances under the Seller's 401(k) plan as
     of the date of transfer, vesting service, and any other employee
     information reasonably required by Purchaser to determine the status of
     each such Scheduled Employee's account under the 401(k) plans of Buyer
     and Seller.

          (iii) Seller shall be solely responsible for providing any and all
     severance benefits owed to Scheduled Employees (and, as applicable, their
     beneficiaries) under the terms of any severance, separation or retention
     plan, policy or arrangement maintained by Seller or relating to the
     Seller's employment of a Scheduled Employee and Seller shall indemnify
     Buyer for any and all loss, cost or expense arising under any severance,
     separation or retention plan, policy or arrangement maintained by Seller
     or relating to Seller's employment of a Scheduled Employee.

          (c)  CONSTRUCTION. Sections 5(a) and 5(b) hereof are solely for the
     purpose of defining the obligations between Purchaser and Seller concerning
     the Scheduled Employees and shall in no way be construed as creating any
     employment contract or other contract between Purchaser or Seller and any
     employee.

                                      8

<PAGE>

                                                                    EXHIBIT 2.1

     6.   CLOSING.

          (a)  LOCATION AND TIME. The closing of the transactions contemplated
     by this Agreement (the "CLOSING") shall take place at the offices of
     Haynes and Boone, LLP, 901 Main Street, Dallas, Texas 75202, at 9:30
     a.m., local time, on March 9, 2000 (the "CLOSING DATE"), or at such other
     time and place as is mutually agreed to by the parties.

          (b)  COSTS. Except as provided in Section 12(f) hereof, Purchaser and
     Seller shall each bear their respective expenses, costs and fees
     (including attorneys and accountants fees and expenses) in connection
     with the transactions contemplated hereby, including the negotiation,
     preparation, execution and delivery of this Agreement and compliance
     herewith, whether or not the transactions contemplated hereby are
     consummated.

          (c)  SELLER'S CLOSING DOCUMENTS. On the Closing Date, Seller shall
     deliver to Purchaser the following (collectively, "SELLER'S CLOSING
     DOCUMENTS"):

               (1)  bills of sale, in form and substance satisfactory to
          Purchaser, for all personal property constituting a part of the
          Purchased Assets and Seller shall deliver actual possession of the
          Purchased Assets, free and clear of all encumbrances (except
          Permitted Encumbrances (as hereinafter defined));

               (2)  assignments, in form and substance reasonably satisfactory
          to Purchaser, of all intangibles constituting a part of the Purchased
          Assets and all Assumed Contracts, licenses, appurtenances and rights
          relating to the Business, except to the extent consent from a third
          party is required to assign such Assumed Contracts, licenses,
          appurtenances and rights and such consent has not been obtained;

               (3)  an assignment of the Facility Lease duly executed by Seller
          evidencing the assignment and assumption of the Facility Lease by
          Purchaser;

               (4)  such other instrument or instruments of transfer as shall
          be necessary or appropriate to vest in Purchaser all rights and title
          to the Purchased Assets;

               (5)  such keys, lock and safe combinations and other similar
          items as Purchaser shall require to obtain full occupation,
          possession and control of the Facility and the Purchased Assets;

               (6)  duly certified copies of the resolutions adopted by
          Seller's board of directors authorizing the execution, delivery and
          due performance of this Agreement and all transactions contemplated
          hereby;

                                      9

<PAGE>

                                                                    EXHIBIT 2.1

               (7)  good standing or similar certificates from the Secretaries
          of State and the appropriate taxing authorities of the States of
          Delaware and Texas with respect to Seller;

               (8)  the license agreement relating to the license of Seller's
          Voyager technology in the form set forth as Exhibit 6(c)(1) (the
          "LICENSE AGREEMENT") duly executed by Seller;

               (9)  the Purchase Price Escrow Agreement (defined below) duly
          executed by Seller;

               (10) such other documents, certificates, instruments or
          agreements which Seller is required to deliver to Purchaser or the
          Scheduled Employees pursuant to this Agreement; and

               (11) Seller shall prepare and deliver to Purchaser, at least
          three business days before the Closing Date, the Current Balance
          Sheet.

          (d)  PURCHASER'S CLOSING DOCUMENTS.  On the Closing Date, Purchaser
     shall deliver to Seller the following (collectively, "PURCHASER'S CLOSING
     DOCUMENTS");

               (1)  payment of the Cash Purchase Price as provided in Section
          3(c);

               (2)  duly certified copies of the resolutions adopted by
          Purchaser's board of directors authorizing the execution, delivery,
          and due performance of this Agreement and all transactions
          contemplated hereby and all documents to be executed and delivered
          hereunder by Purchaser at Closing;

               (3)  instruments executed by Purchaser, in form and substance
          satisfactory to Seller, whereby Purchaser agrees to assume the
          Assumed Liabilities;

               (4)  an assignment of the Facility Lease duly executed by Seller
          evidencing the assignment and assumption of the Facility Lease by
          Purchaser;

               (5)  such further instruments as any person to whom Seller is
          obligated with respect to any Assumed Liability may timely and
          reasonably request in order to effect the assumption by Purchaser of
          Seller's obligations thereunder;

               (6)  the License Agreement duly executed by Purchaser;

               (7)  the Purchase Price Escrow Agreement duly executed by
          Purchaser; and


                                     10

<PAGE>

                                                                    EXHIBIT 2.1

               (8)  such other documents, certificates, instruments,
          agreements, which Purchaser is required to deliver to Seller or the
          Scheduled Employees pursuant to this Agreement.

          (e)  FURTHER ASSURANCES. Seller and Purchaser agree that, at and
     after the Closing Date:

               (1)  at the request of Purchaser, Seller shall execute and
          deliver such further instruments of transfer and assumption as may be
          necessary or appropriate, and shall take all commercially reasonable
          action as may be necessary or appropriate (A) to vest in Purchaser
          title to the Purchased Assets, (B) to transfer to Purchaser all
          licenses, agreements and permits necessary for the operation of the
          Business (other than the Excluded Assets) and to the extent that
          consents to the assignment of such licenses, agreements and permits
          have not been obtained prior to Closing, to secure the benefits and
          liabilities of such licenses, agreement and permits in some other
          manner and (c) to aid and assist Purchaser in collecting and reducing
          to possession any or all of the Purchased Assets; and

               (2)  each will at any time and from time to time after the
          Closing, upon the request of the other, execute, acknowledge,
          deliver, and perform, or cause to be executed, acknowledged,
          delivered, and performed, all such further acts, deeds, assignments,
          transfers, conveyances, powers of attorney, assumption agreements,
          and assurances as may reasonably be required in connection with the
          transactions contemplated by this Agreement.

               Notwithstanding anything in this Agreement to the contrary, this
          Agreement shall not constitute an agreement to assign any agreement,
          license, approval, authorization, contract, lease or other commitment
          if an attempted assignment thereof without the consent of a third
          party thereto would constitute a breach thereof.

          (f)  PRORATIONS.  At Closing, Seller and Purchaser shall prorate as
     of the Closing Date:

               (1)  all rent payable on the Facility Lease or any leases of
          equipment which are being assumed by Purchaser;

               (2)  all utility bills for utilities provided to the Facility;
          and

               (3)  all personal property taxes levied or assessed against any
          of the Purchased Assets for the current tax year.

                                     11

<PAGE>

                                                                    EXHIBIT 2.1

          (g)  PURCHASE PRICE ESCROW. Purchaser shall deliver to Bank One,
     Texas, NA (the "ESCROW AGENT") $800,000.00 by wire transfer of immediately
     available funds at the Closing (the "PURCHASE PRICE ESCROW FUNDS").
     Purchaser and Seller shall enter into an escrow agreement in the form of
     EXHIBIT 6(g) (the "PURCHASE PRICE ESCROW AGREEMENT") with the Escrow Agent
     that provides the following:

               (1)  Purchaser shall deliver to the Escrow Agent the Purchase
          Price Escrow Funds by wire transfer of immediately available funds at
          the Closing.

               (2)  The Purchase Price Escrow Funds shall remain in the escrow
          account for 365 days (the "PURCHASE PRICE ESCROW PERIOD"). If no
          claims against Seller exist at the end of the Purchase Price Escrow
          Period, the Purchase Price Escrow Funds shall be paid to Seller on
          the day after the end of the Purchase Price Escrow Period. Interest
          income shall accrue to the benefit of Seller. The Purchase Price
          Escrow Funds shall be placed in an interest bearing account
          acceptable to Seller, Purchaser and the Escrow Agent. Purchaser and
          Seller shall each pay 50% of all of the costs and expenses of the
          Escrow Agent in connection with the Purchase Price Escrow Funds.

               (3)  The Purchase Price Escrow Funds shall be released only as
          set forth in the Purchase Price Escrow Agreement.

          (h)  WORKING CAPITAL ADJUSTMENT. The Purchase Price shall be subject
     to adjustment in accordance with the following:

               (1)  On a date not more than twenty (20) days after the Closing
          Date, Seller shall prepare and deliver to Purchaser a "CLOSING DATE
          BALANCE SHEET" (herein so called) consisting of an unaudited balance
          sheet of the Business as of the Closing Date which shall reflect the
          Current Assets (defined below) and Current Liabilities (defined
          below) as of the Closing Date. Such Closing Date Balance Sheet
          shall be prepared by the Seller. If within ten (10) days following
          delivery of the Closing Date Balance Sheet, Purchaser has not given
          Seller notice of its objection to the Closing Date Balance Sheet
          (such notice must contain a statement of the basis of Purchaser's
          objection), then the Closing Date Balance Sheet prepared by Seller
          shall be used in computing the Adjustment Amount (defined below).
          If Purchaser gives such notice of objection, then Ernst & Young LLP,
          Seller's certified public accountants and PricewaterhouseCoopers
          LLP, Purchaser's certified public accountants, shall use their best
          efforts to resolve the issues in dispute. If such accounting firms
          are unable to resolve the issues in dispute within twenty (20) days
          thereafter, then the issues in dispute shall be submitted to
          mutually agreed upon certified public accountants (the
          "ACCOUNTANTS"), for resolution. If issues in dispute are submitted
          to the Accountants for resolution, (i) each party shall furnish to
          the Accountants such work papers and

                                     12

<PAGE>

                                                                    EXHIBIT 2.1

          other documents and information relating to the disputed issues as
          the Accountants may request and are available to that party, and
          shall be afforded the opportunity to present to the Accountants any
          material relating to the determination and to discuss the
          determination with the Accountants; (ii) the determination by the
          Accountants, as set forth in a notice delivered to both parties by
          the Accountants, shall be binding and conclusive on the parties; and
          (iii) Purchaser and Seller shall each bear 50% of the fees of the
          Accountants for such determination. The Accountants shall use their
          best efforts to resolve any disputes within thirty (30) days after
          submission.

          "CURRENT ASSETS" means the cash, consolidated inventory, accounts
          receivable, prepaid expenses and other current assets of the
          Business, and noncurrent investments, in each case determined in a
          manner consistent with the presentation in the Current Balance
          Sheet. "CURRENT LIABILITIES" means the consolidated accounts
          payable, accrued expenses, customer deposits, and other current
          liabilities of the Business, in each case determined in accordance
          with the presentation in the Current Balance Sheet.

               (2)  On the tenth business day following the final resolution of
          any disputes with respect to the Closing Date Balance Sheet if the
          Closing Date Balance Sheet shows the Working Capital (defined below)
          of the Business on the Closing Date is less than $300,000.00, Seller
          shall pay the difference to Purchaser. If the Closing Date Balance
          Sheet shows the Working Capital of the Business on the Closing Date
          exceeds $300,000, Purchaser shall pay the excess to the Seller. The
          amount owed or owing shall constitute the "ADJUSTMENT AMOUNT" (herein
          so called). To the extent any amounts are owed by Seller, it is
          understood and agreed that Purchaser shall be entitled to receive
          such amount from the Escrow Funds, to the extent then available.

          "WORKING CAPITAL" shall mean the difference between Current Assets
          and Current Liabilities as shown on the Closing Date Balance Sheet.

          (i)  EMPLOYEE RETENTION FUNDS.  At the Closing, $270,000 (the
     "EMPLOYEE RETENTION FUNDS") shall be deducted from the Purchase Price paid
     to Seller. The Employee Retention Funds shall be used by Purchaser solely
     to make payments to the Scheduled Employees for the purpose of retaining
     such employees in the employment of Purchaser.

     7.   REPRESENTATIONS AND WARRANTIES OF SELLER.  Seller hereby represents
and warrants to Purchaser as follows (each such representation and warranty
being qualified in its entirety by the disclosures set forth on the Disclosure
Schedule of Seller attached hereto) (the "DISCLOSURE SCHEDULE"):

                                     13

<PAGE>

                                                                    EXHIBIT 2.1

          (a)  ORGANIZATION.  Seller is a corporation duly organized, validly
     existing and in good standing under the laws of the State of Delaware.
     Seller has the requisite corporate power and authority to own its property
     and assets and to carry on its business as now being conducted.  Seller is
     duly qualified, registered or licensed to do business as a foreign
     corporation in each other jurisdiction wherein the nature of its activities
     or of its properties owned or leased makes such qualification necessary and
     failure to be so qualified, registered or licensed could have a material
     adverse effect upon the Business or the Purchased Assets.  No stockholder,
     officer, director or employee of Seller or any affiliated entity is
     currently a party to any transaction with Seller relating to any aspect of
     the Business.

          (b)  AUTHORIZATION OF AGREEMENT.  Seller has the requisite corporate
     power and authority to execute and deliver this Agreement and to consummate
     the transactions contemplated hereby.  The execution and delivery of this
     Agreement by Seller and the performance by Seller of its obligations
     hereunder have been duly authorized by all necessary action on the part of
     Seller, including without limitation approval by Seller's board of
     directors.  The execution and delivery of this Agreement and the
     consummation of the transactions contemplated hereby do not and will not
     conflict with, or result in a breach of, or constitute a default under, the
     terms or conditions of Seller's Certificate of Incorporation, Bylaws, any
     court or administrative order, judgment or decree, any agreement or
     instrument to which Seller is a party or by which Seller or any of its
     assets is bound (subject to obtaining consents to the assignment of the
     agreements set forth on SCHEDULE 7(j)) or, to the knowledge of Seller, any
     statute or regulation of any governmental agency.  The execution and
     delivery of this Agreement and the consummation of the transactions
     contemplated hereby do not require the consent of any third party.  This
     Agreement and all other instruments required hereby to be executed and
     delivered by Seller are, or when delivered will be, valid and binding
     obligations of Seller, enforceable against Seller in accordance with their
     terms, except to the extent that such enforceability may be limited by
     applicable bankruptcy, insolvency, reorganization or other laws affecting
     the enforcement of creditors' rights generally and except that the
     availability of equitable remedies, including specific performance, is
     subject to the discretion of the court before which any proceedings
     therefor may be brought.

          (c)  BUSINESS FINANCIAL STATEMENTS.  Schedule 7(c) sets forth the
     Seller's unaudited balance sheet for the Business as of December 31, 1999
     (the "CURRENT BALANCE SHEET"). The Current Balance Sheet is correct in all
     material respects and has been prepared in accordance with GAAP
     consistently applied on a basis consistent throughout the periods indicated
     and consistent with each other (except as set forth therein and except that
     it does not contain footnotes and other presentation items that may be
     required by GAAP).  The Current Balance Sheet presents fairly the financial
     condition, of the Business as of the date indicated therein, subject to
     normal year-end adjustments, which are not material in amount or
     significance in any individual case or in the aggregate.


                                      14
<PAGE>

                                                                    EXHIBIT 2.1

          (d)  TAX MATTERS.

               (1)  Seller has duly and timely filed all Tax Returns with the
          appropriate governmental or taxing authority and has duly completed
          and correctly reported in all material respects all income and all
          other amounts and information required to be reported thereon.

               (2)  Seller has duly and timely paid, accrued or properly
          provided for all Taxes, including all installments on account of Taxes
          for the current year, that are due and payable or collectible by it.

               (3)  Neither Seller nor any member of any affiliated group
          (within the meaning of Section 1504 of the Code), combined group,
          consolidated or unitary group (any such affiliated, combined,
          consolidated or unitary group hereinafter referred to as an
          "AFFILIATED GROUP") of which Seller is or was a member has received
          notice of any deficiency or assessment from any federal, state, local
          or foreign governmental authority with respect to any liability for
          Taxes attributable to the Business or the Purchased Assets.  No
          administrative, judicial or other proceeding is presently pending with
          respect to any Taxes or Tax Returns of Seller or any member of an
          Affiliated Group of which Seller is or was a member or otherwise with
          respect to the Business or the Purchased Assets.

               (4)  There are no actions, suits, proceedings, investigations,
          audits or claims now pending or threatened in a writing delivered to
          Seller against Seller relating to the Business in respect of any Taxes
          and there are no matters under discussion, audit or appeal with any
          governmental authority relating to Taxes.

               (5)  There are no liens for Taxes upon the Purchased Assets,
          except for liens for Taxes not yet due.

               (6)  None of the Purchased Assets transferred pursuant to this
          Agreement is property that is or will be required to treat as being
          owned by another person pursuant to the provisions of Section 168(f)
          of the Code (as in effect prior to the amendment by the Tax Reform Act
          of 1986) or is "tax-exempt use property" within the meaning of Section
          168 of the Code.

               (7)  Seller has timely deducted and withheld and will deduct and
          withhold from any amount paid or credited or deemed paid or credited
          up to and including the Closing Date by it to or for the account or
          benefit of any person, including, without limitation, any of its
          employees, officers or directors, the amount of all Taxes and other
          deductions required by any applicable law to be deducted or withheld
          from any


                                      15
<PAGE>

                                                                    EXHIBIT 2.1

          such amount and has duly and timely collected and remitted and will
          collect and remit the same to the appropriate governmental authority.

          (e)  ACTIONS, SUITS, PROCEEDINGS.  There are no actions, suits or
     proceedings (including, without limitation, condemnation proceedings and
     actions, suits or proceedings in respect of product liability claims)
     pending or, to the knowledge of Seller, threatened against Seller or any of
     its properties or business in any court or before any federal, state,
     municipal, foreign or other governmental agency relating to the Purchased
     Assets or the Business or the consummation of the transactions contemplated
     hereby.  Neither Seller, the Business nor the Purchased Assets are subject
     to any order, writ, injunction or decree of any court or governmental
     agency relating to the Business or the Purchased Assets.

          (f)  COMPLIANCE WITH APPLICABLE LAWS AND OTHER INSTRUMENTS.  The
     Business is being, and since its inception has been, conducted in all
     material respects in compliance with all applicable laws, rules or
     regulations of all governmental authorities.  Seller is not in violation of
     its Certificate of Incorporation or Bylaws.

          (g)  FACILITY LEASE.  The Facility Lease is the only lease or sublease
     of real property relating to real property used or occupied by Seller in
     connection with the Business. All payments required to be made by Seller
     pursuant to the Facility Lease have been duly paid and Seller is not
     otherwise in default in meeting its obligations under the Facility Lease or
     in violation of any provision of the Facility Lease.

          (h)  TITLE TO THE PURCHASED ASSETS.  Seller has good and marketable
     title to all of the personal property included in the Purchased Assets,
     free and clear of all security interests, liens, mortgages, encumbrances
     and restrictions, except encumbrances listed and described in SCHEDULE 7(h)
     hereto (the "PERMITTED ENCUMBRANCES").  To the extent that any Permitted
     Encumbrances contain covenants or obligations by which Seller is bound,
     Seller is not in default under such covenants or obligations.

          (i)  INTELLECTUAL PROPERTY RIGHTS.  SCHEDULE 7(i) hereto contains a
     complete and accurate list as of the date hereof of (1) all patents,
     registered trademarks, trade names, registered service marks and registered
     copyrights (and all applications therefor) owned by Seller that are
     reasonably necessary to conduct the Business in the manner and to the
     extent presently conducted by Seller, and (2) all agreements relating to
     the Intellectual Property which Seller is licensed or authorized to use by
     others and included in the Purchased Assets. Seller owns or has the right
     to use all Intellectual Property included in the Purchased Assets. Other
     than with respect to the agreements listed in SCHEDULE 7(i), Seller is not
     a party to any agreement or contract which obligates Seller to pay
     royalties, fees or other payments to any owner of, licensor of, or other
     claimant to, any Intellectual Property included in the Purchased Assets.
     Seller has not transferred or conveyed any rights to others in the
     Intellectual Property of Seller included in the Purchased Assets other than
     rights to use that


                                      16
<PAGE>

                                                                    EXHIBIT 2.1

     are expressly granted in connection with customer licenses.  No claims
     have been asserted in writing and delivered to Seller by any person to
     the use in the conduct of the Business of any Intellectual Property
     included in the Purchased Assets or challenging or questioning the
     validity or effectiveness of any such Intellectual Property.  To the
     Seller's knowledge, there exists no valid basis for any such claim,
     except for such claims an adverse determination of which, in the
     aggregate, could not have a material adverse effect on the Business;
     and, to the knowledge of Seller, the use of the Intellectual Property
     included in the Purchased Assets in the conduct of the Business does not
     infringe on the rights of any person.  Except for the Excluded Assets,
     the Intellectual Property included in the Purchased Assets constitute
     all of the Intellectual Property reasonably necessary to conduct the
     Business in the manner and to the extent presently conducted.

          (j)  CONTRACTS, LEASES, COMMITMENTS AND AGREEMENTS.  All material
     contracts, leases, agreements and commitments relating to the Business or
     the Purchased Assets that exist as of the date hereof are set forth on
     SCHEDULE 1(c).  For the purpose of the foregoing sentence, material
     contracts, leases, agreements or commitments are contracts, leases,
     agreements or commitments providing for payment or receipt of $5,000 or
     more over the life of the contract or which may not be terminated without
     penalty with notice of 30 days or less.  Seller and each other party
     thereto have in all respects substantially performed all obligations
     required to be performed by them to date, and are not in default under any
     of the Assumed Contracts.  Each of the Assumed Contracts is in full force
     and effect and is assignable to Purchaser without the consent of third
     parties, and Seller has not waived or assigned to any other person any of
     its rights thereunder.

          (k)  COMPOSITION AND CONDITION OF PURCHASED ASSETS.  The Purchased
     Assets comprise all material property and assets currently employed by
     Seller in the Business, except for the Excluded Assets.  Except for the
     Excluded Assets, the Purchased Assets are all assets that are reasonably
     necessary to conduct the Business in the manner and to the extent presently
     conducted by Seller.

          (l)  INSURANCE.  Seller maintains and will maintain prior to the
     Closing such policies of insurance, issued by responsible insurers, as are
     appropriate to the Business and the Purchased Assets, in such amounts and
     against such risks as it believes are adequate.  All such policies of
     insurance are in full force and effect and Seller is not in default, as to
     the payment of premiums or otherwise, under the terms of any such policy.

          (m)  MAJOR SUPPLIERS AND CUSTOMERS.   SCHEDULE 7(m) lists each
     supplier of goods and services related to the Business to whom Seller paid
     in excess of $15,000 in the aggregate, and each customer related to the
     Business to whom Seller billed in excess of $25,000 in the aggregate,
     during the 12 month period ending December 31, 1999.  No material supplier
     or customer has expressed, either orally or in writing, any intention to
     change its relationship or the terms upon which it conducts business with
     respect to the


                                      17
<PAGE>

                                                                    EXHIBIT 2.1

     Business as a result of the transfer of the Purchased Assets as
     contemplated in this Agreement.

          (n)  EMPLOYEE PLANS.

               (1)  The requirements of Section 4980B of the Code and Part 6 of
          Subtitle B of Title I of ERISA relating to COBRA continuation of
          health coverage have been materially satisfied with respect to each
          "group health  plan" (within the meaning of Section 4980B(g)(2) of the
          Code) of Seller in which any employee whose last employment was with
          respect to the assets sold pursuant to this Agreement participated.

               (2)  Neither Seller nor any ERISA Affiliate maintains or has ever
          maintained a "multiemployer plan" within the meaning of Section
          4001(a)(3) of ERISA.

          (o)  LABOR MATTERS.

               (1)  Seller is not a party to any collective bargaining
          agreement, and no union or association of employees has been certified
          or recognized as the collective bargaining representative of any of
          Seller's employees or has attempted to engage in negotiations with
          Seller regarding terms and conditions of employment.

               (2)  Seller is in compliance in all material respects with
          applicable federal, state and local laws and regulations governing
          employee relations, including but not limited to anti-discrimination
          laws, wage/hour laws, labor relations laws and occupational safety and
          health laws, and no suits, charges or administrative proceedings
          relating to any such law or regulation are pending, and no suit,
          charge or administrative investigation alleging a violation of any
          such law or regulation has been threatened orally to Seller or in a
          writing delivered to Seller.

          (p)  GOVERNMENT LICENSE AND REGULATION.  Set forth on SCHEDULE 1(g) is
     a list of all material domestic and foreign governmental and third party
     licenses, permits, certificates, consents, approvals, waivers,
     authorizations, and registrations (collectively, "APPROVALS") as of the
     date hereof which Seller has obtained, which are all of the material
     Approvals necessary to conduct the Business as presently conducted and to
     own and use the Purchased Assets, and such Approvals are in full force and
     effect.  All of the rights of Seller under such Approvals are transferable
     to Purchaser under applicable law solely upon the assignment of such
     Approvals by Seller to Purchaser hereunder and will be exercisable by
     Purchaser after the consummation of the transactions contemplated by this
     Agreement.  No proceeding is pending or threatened regarding the revocation
     or limitation of any such Approvals and there is no basis or grounds for
     any such revocation or limitation.


                                      18
<PAGE>

                                                                    EXHIBIT 2.1

          (q)  LOCATION OF THE ASSETS.  All of the tangible Personal Property
     included in the Purchased Assets will be located at the Facility at the
     Closing Date.

          (r)  YEAR 2000. All computer hardware and software included in the
     Purchased Assets and material to the operations of the Business that were
     created by Seller and, to the knowledge of Seller, were not created by
     Seller are Year 2000 Complaint (defined below). "YEAR 2000 COMPLIANT" means
     that the hardware and software will not materially fail to operate
     according to their specifications as a result of the use of properly
     formatted date data, before and after the year 2000, for dates within the
     normal operating life of such hardware and software.

     8.   REPRESENTATIONS AND WARRANTIES OF PURCHASER.  Purchaser hereby
represents and warrants to Seller as follows:

          (a)  CORPORATE ORGANIZATION.  Purchaser is a corporation duly
     organized and validly existing under the laws of the State of Delaware.
     Purchaser has the corporate power and authority to own its property and
     assets and to carry on its business as now conducted.

          (b)  CORPORATE AUTHORITY.  Purchaser has the requisite corporate power
     and authority to execute and deliver this Agreement and to consummate the
     transactions contemplated hereby.  The execution and delivery of this
     Agreement and performance by Purchaser of its obligations hereunder have
     been duly authorized by all necessary corporate action on the part of
     Purchaser.  The execution and delivery of this Agreement and the
     consummation of the transactions contemplated hereby do not and will not
     conflict with, or result in a breach of, or constitute a default under, the
     terms and conditions of the Certificate of Incorporation or Bylaws of
     Purchaser, any court or administrative order, judgment or decree any
     agreement or instrument to which Purchaser is a party or by which it or any
     of its assets is bound or, to the knowledge of Purchaser, any statute or
     regulation of any governmental agency.  This Agreement and all other
     instruments required hereby to be executed and delivered by Purchaser are,
     or when delivered will be, valid and binding obligations of Purchaser
     enforceable against Purchaser in accordance with their terms, except to the
     extent that such enforceability may be limited by applicable bankruptcy,
     insolvency, reorganization or other laws affecting the enforcement of
     creditors' rights generally and except that the availability of equitable
     remedies, including specific performance, is subject to the discretion of
     the court before which any proceedings therefor may be brought.  The
     execution and delivery of this Agreement and the consummation of the
     transactions contemplated hereby do not require the consent of any third
     party.

          (c)  LITIGATION AND OTHER PROCEEDINGS.  There is no litigation,
     action, suit, investigation or proceeding pending or, to Purchaser's
     knowledge, threatened against or affecting Purchaser's business before any
     court, agency or other governmental body that


                                      19
<PAGE>

                                                                    EXHIBIT 2.1

     would result in any material adverse effect upon Purchaser's ability to
     perform its obligations under this Agreement.

     9.   CONDITIONS TO OBLIGATION OF PURCHASER TO CLOSE.  The obligations of
Purchaser to effect the closing of the transactions contemplated by this
Agreement is subject to the satisfaction prior to or at the Closing of the
following conditions (each of which is acknowledged to be included for the
exclusive benefit of Purchaser and may be waived by Purchaser in whole or in
part):

          (a)  REPRESENTATIONS AND WARRANTIES. There shall be no failure of the
     representations and warranties of Seller to be true and correct at the
     Closing Date that would have a material adverse effect on the Purchaser,
     except as otherwise expressly contemplated by this Agreement and except for
     such representations and warranties made as of a particular date.

          (b)  OBSERVANCE AND PERFORMANCE.  Seller shall have performed and
     complied in all material respects with all covenants, obligations and
     agreements required by this Agreement to be performed and complied with by
     it prior to or as of the Closing Date.

          (c)  VIOLATIONS OF LAWS AND ORDINANCES.  On or before the Closing
     Date, Seller shall not have received any notice or have knowledge of any
     injunction or lawsuit pending or threatened, any violation or alleged
     violation of any city ordinance, state law, rule or regulation of any
     governmental authority, with respect to Seller's use and operation of any
     of the Purchased Assets or Assumed Liabilities that could materially
     interfere with, or materially adversely affect, the Business, the Purchased
     Assets or Seller's ability to consummate the transactions contemplated by
     this Agreement.

          (d)  OFFICER'S CERTIFICATE.  Seller shall have delivered to Purchaser
     a certificate, dated the Closing Date, executed by a duly authorized
     executive officer of Seller and certifying to the satisfaction of the
     conditions specified in Sections 9(a), (b), and (c) hereof.

          (e)  CHANGE IN ASSETS.  There shall have been no material adverse
     change in the nature of the Purchased Assets between the date hereof and
     the Closing;

          (f)  KEY EMPLOYEES.  All employees designated as key employees on
     Schedule 5(a) shall have accepted employment offers with Purchaser.

          (g)  SEARCHES.  Purchaser shall have received, as of a date no more
     than 15 days prior to the Closing Date, Uniform Commercial Code searches
     against Seller from the Secretaries of State of the States of Delaware and
     Texas and from such other jurisdictions as Purchaser shall reasonably
     request, together with tax lien and judgment searches, disclosing no liens
     or security interests against the Purchased Assets other than the Permitted


                                      20
<PAGE>

                                                                    EXHIBIT 2.1

     Encumbrances and liens and security interests for which Seller shall have
     obtained releases on or before the Closing Date.

          (h)  CONSENTS.  Purchaser shall have received duly executed copies of
     all material consents and agreements necessary to effect (i) the transfer
     of the Purchased Assets to Purchaser, including, without limitation, the
     assignment to Purchaser of the Assumed Contracts, and (ii) the assumption
     of the Assumed Liabilities.  Purchaser hereby agrees to use commercially
     reasonable efforts to assist Seller in obtaining such consents and
     agreements.

          (i)  CLOSING DOCUMENTS.  Purchaser shall have received duly executed
     copies of the Seller's Closing Documents and such other bills of sale,
     assignments and other documents of transfer reasonably required to transfer
     to Purchaser the interests of Seller in the Purchased Assets and the
     Business, and to assume the Assumed Liabilities, consistent with the terms
     of this Agreement.

          (j)  PROCEEDINGS AND DOCUMENTS.  All corporate and other proceedings
     and actions taken in connection with the transactions contemplated hereby
     and all certificates, opinions, agreements, instruments and documents
     mentioned herein or incident to any such transaction shall be reasonably
     satisfactory in form and substance to Purchaser and its counsel.

          (k)  HIRING OF EMPLOYEES.   Purchaser shall have offered at-will
     employment to all Scheduled Employees and before the Closing eighty-five
     percent (85%) of such individuals shall have accepted employment with
     Purchaser.

     10.  CONDITIONS TO OBLIGATION OF SELLER TO CLOSE.  The obligation of
Seller to effect the transactions contemplated by this Agreement is subject
to the satisfaction prior to or at the Closing of the following conditions
(each of which is acknowledged to be included for the exclusive benefit of
Seller and may be waived by Seller in whole or in part):

          (a)  REPRESENTATIONS AND WARRANTIES.  There shall be no failure of the
     representations and warranties of Purchaser to be true and correct at the
     Closing Date that would have a material adverse effect on the Seller,
     except as expressly contemplated by this Agreement.

          (b)  OBSERVANCE AND PERFORMANCE.  Purchaser shall have performed and
     complied in all material respects with all covenants and agreements
     required by this Agreement to be performed and complied with by it prior to
     or as of the Closing Date.

          (c)  VIOLATIONS OF LAWS AND ORDINANCES.  On or before the Closing
     Date, Purchaser shall not have received any notice or have knowledge of any
     injunction or lawsuit pending or threatened, any violation or alleged
     violation of any city ordinance, state law, rule


                                      21
<PAGE>

                                                                    EXHIBIT 2.1

     or regulation of any governmental authority that could materially
     interfere with, or materially adversely affect, the Purchaser's ability
     to consummate the transactions contemplated by this Agreement.

          (d)  OFFICER'S CERTIFICATE.  Purchaser shall have delivered to Seller
     a certificate, dated the Closing Date, executed by a duly authorized
     executive officer of Purchaser and certifying to the satisfaction of the
     conditions specified in Sections 10(a), (b) and (c) hereof.

          (e)  CLOSING DOCUMENTS.  Seller shall have received the Purchaser's
     Closing Documents and such assumption agreements and other documents of
     transfer reasonably required to transfer to Purchaser all obligations of
     Seller with respect to the Assumed Contracts and the Assumed Liabilities
     consistent with the terms of this Agreement.

          (f)  PROCEEDINGS AND DOCUMENTS.  All corporate and other proceedings
     and actions taken in connection with the transactions contemplated hereby
     and all certificates, opinions, agreements, instruments and documents
     mentioned herein or incident to any such transaction which are to be
     prepared and delivered by Purchaser shall be reasonably satisfactory in
     form and substance to Seller and its counsel.

          (g)  PURCHASE ORDER.  Seller shall have entered into a purchase order
     with Motorola, Inc. with respect to services that are being performed as of
     the date hereof on the premises of Motorola, Inc., a consultant of Seller.

     11.  GOVERNMENTAL FILINGS.  Seller and Purchaser shall cooperate with
respect to, and diligently pursue completion of, all filings with or approvals
of governmental agencies required in connection with the transactions
contemplated by this Agreement, if any.

     12.  COVENANTS OF SELLER.

          (a)  OPERATION OF BUSINESS PRIOR TO CLOSING.  Seller covenants and
     agrees that, except with the prior written consent of Purchaser, from and
     after the date hereof to the Closing Date:

               (1)  Seller shall use commercially reasonable efforts to preserve
          intact the business organization rights and privileges pertinent to
          the Business, to preserve for Purchaser the good will of suppliers,
          customers and others having business relationships with the Business,
          to preserve intact its credit arrangements with banks, other financial
          institutions and its creditors, and to preserve its relationship with
          its officers, directors, and employees, consultants and independent
          contractors;

               (2)   Seller shall maintain its books and records during such
          period in a manner consistent with past practice;


                                      22
<PAGE>

                                                                    EXHIBIT 2.1

               (3)  Seller shall not sell, transfer, dispose of or abandon any
          portion of the Purchased Assets, except inventory sold in the ordinary
          course of business and consistent with past practice in an amount less
          than $5,000;

               (4)  Seller shall not permit any of the Purchased Assets to
          become subject to any lien, pledge, security interest, conditional
          sale agreement, license agreement, charge or encumbrance, other than
          Permitted Encumbrances;

               (5)  Seller shall not modify or amend any of the Assumed
          Contracts or waive or assign to any third party any of its rights
          thereunder;

               (6)  Seller shall maintain and keep all tangible Purchased Assets
          in good condition and repair, ordinary wear and tear excepted, and
          will continue to perform all usual and normal maintenance of and upon
          the Purchased Assets in accordance with Seller's past practice;

               (7)  Seller shall pay accounts payable and other obligations of
          the Business when they become due and payable in the ordinary course
          of business consistent with prior practice;

               (8)  Seller shall not disclose any confidential information
          related to the Business to any person or entity unless such person is
          employed by Seller or Purchaser;

               (9)  Except as contemplated by this Agreement, Seller shall not
          grant any salary increase or bonus to any Scheduled Employee, or enter
          into any new, or amend or alter any existing, employment-related
          agreement with any Scheduled Employee, or provide other compensatory
          benefits to any Scheduled Employee (except normal wage or salary
          payments consistent with past practices).

               (10) Without limiting the generality of the foregoing, Seller
          shall in all other respects operate the Business in the usual, regular
          and ordinary course and consistent with past practice in compliance
          with all applicable laws, rules and regulations.

          (b)  NOTICES TO EMPLOYEES; CONTINUATION OF BENEFITS.  Upon cessation
     of employment of the Scheduled Employees hereunder by Seller, Seller shall
     give each of the Scheduled Employees all required notices and information
     with respect to the continuation of certain health insurance benefits by
     Seller.  Seller agrees to provide continuation health care coverage, if
     any, required pursuant to Section 4980B of the Code on behalf of any


                                      23
<PAGE>

                                                                    EXHIBIT 2.1

     Scheduled Employee (or any spouse or dependent of such Scheduled Employee)
     who elects not to accept employment with Purchaser or any of its
     affiliates.

          (c)  ACCESS AND INFORMATION.  Prior to the Closing Date, Seller will
     (and will cause each of its accountants, counsel, consultants, employees
     and agents) give the Purchaser and the Purchaser's accountants, counsel,
     consultants, employees and agents ("PURCHASER'S REPRESENTATIVES"), full
     access during normal business hours to, and furnish them with all
     documents, records, course templates, work papers and information with
     respect to, all of Seller's properties, assets, books, contracts,
     commitments, reports and records relating to the Business, as the Purchaser
     shall reasonably request.  In addition, prior to the Closing Date, Seller
     will permit Purchaser's Representatives reasonable access to such personnel
     of Seller during normal business hours as may be necessary or useful to the
     Purchaser in its review of the assets and business affairs of the Business
     and will keep the Purchaser generally informed as to the affairs of the
     Business.

          (d)  PUBLIC ANNOUNCEMENTS.  Prior to the Closing Date, except as
     required by applicable law, the Seller shall not, and it shall not permit
     any affiliate or representative to, make any public announcement in respect
     of this Agreement or the transactions contemplated hereby without the prior
     written consent of the Purchaser.

          (e)  NOTICE OF CHANGES. At all times prior to the Closing, Seller
     will, promptly upon becoming aware of such information, notify Purchaser in
     writing of any fact, condition, event or occurrence that will or may
     reasonably be likely to result in a failure of any of the conditions
     contained in Sections 9(a), (b), or (c) to be satisfied.

          (f)  TRANSFER TAXES.  Seller shall be responsible for the timely
     payment of, and shall indemnify and hold harmless the Purchaser against,
     all sales, use, value added, documentary, stamp, gross receipts,
     registration, transfer, conveyance, excise, recording, license and other
     similar taxes and fees ("TRANSFER TAXES"), arising out of or in connection
     with or attributable to the transactions effected pursuant to this
     Agreement.  Seller shall prepare and timely file all tax returns required
     to be filed in respect of any Transfer Taxes; PROVIDED that Purchaser shall
     be permitted to prepare any such tax returns that are the primary
     responsibility of Purchaser under applicable law.  Purchaser's preparation
     of any such tax returns shall be subject to Seller's approval, which
     approval shall not be unreasonably withheld.

          (g)  NO SOLICITATIONS.  The Seller shall not, directly or indirectly,
     through any officer, director, employee, stockholder, representative or
     agent of the Seller, solicit or encourage the initiation or submission of
     any inquiries, proposals or offers regarding the acquisition of all or any
     portion of the Purchased Assets, whether in writing or not, or similar
     transactions involving the Purchased Assets (any of the foregoing referred
     to herein as an "ACQUISITION PROPOSAL").  Seller further agrees that it
     will not, and that none of its officers


                                      24
<PAGE>

                                                                    EXHIBIT 2.1

     will, and that Seller will direct and cause its employees, agents and
     representatives (including any investment banker, attorney or accountant
     retained by any of them) not to, directly or indirectly, engage in any
     negotiations concerning, or provide any confidential information or data
     to, or have any discussions with, any person relating to an Acquisition
     Proposal, or otherwise facilitate any effort or attempt to make or
     implement an Acquisition Proposal.  Seller shall promptly notify Purchaser
     after receipt of any Acquisition Proposal or any request for information
     relating to Purchased Assets in connection with an Acquisition Proposal
     or for access to the Purchased Assets that informs the Board of Directors
     of Seller that a third party is considering making, or has made, an
     Acquisition Proposal.  Seller shall immediately cease and cause to be
     terminated any existing activities, discussions or negotiations with any
     parties conducted heretofore with respect to any of the foregoing.

          (h)  FURTHER ACTIONS.  Seller shall take all other actions prior to,
     on, or after the Closing Date as shall be reasonably required to comply
     with all other covenants of this Agreement or which shall be reasonably
     required to put Purchaser in actual possession and operating control of the
     Purchased Assets.  Subject to the terms and conditions of this Agreement,
     Seller shall use its commercially reasonable efforts to take, or cause to
     be taken, all actions and to do, or cause to be done, all things necessary,
     proper or advisable to consummate and make effective the transactions
     contemplated by this Agreement, including, but not limited to (1) Seller
     using its commercially reasonable efforts to obtain, prior to the Closing
     Date, all licenses, permits, consents, approvals, authorizations,
     qualifications and orders of governmental authorities and parties to
     contracts with Seller as are necessary to the consummation of the
     transactions contemplated hereby, (2) Seller using its commercially
     reasonable efforts to effect all necessary registrations and filings, and
     (3) Seller using its commercially reasonable efforts to furnish Purchaser
     such information as is reasonably requested in connection with the
     foregoing.

          (i)  COVENANT NOT TO SUE.  Seller hereby agrees that Seller shall not
     institute, prosecute or in any way aid in the institution or prosecution of
     any claim, suit, or cause of action against Purchaser for the Purchaser's
     use of the assets listed on Schedule 2(n).

     13.  COVENANT NOT TO COMPETE.  In consideration of the payment by Purchaser
of the Purchase Price and the assumption of the Assumed Liabilities, Seller
hereby agrees that, for a period of two years from the Closing Date, it shall
not, through any person controlling, controlled by or under common control with
Seller, alone or in association with any other person, firm, corporation,
partnership or other business organization, except as expressly provided for
herein:

          (a)  Directly engage in, or own or acquire any controlling interest in
     any company whose primary business is to engage in, electronics
     manufacturing yield and productivity improvement through development,
     application, and support of factory monitoring and control software
     solutions (a "COMPETITIVE BUSINESS"). For purposes of this Section 13(a),
     Seller may acquire any interest which arises solely from the ownership of
     less than a 5%


                                      25
<PAGE>

                                                                    EXHIBIT 2.1

     equity interest in a corporation whose stock is regularly traded on any
     national securities exchange or in the over-the-counter market.

          (b)  Seller acknowledges that the failure or threatened failure to
     comply with the provisions of this Section 13 will result in irreparable
     and continuing damage to Purchaser for which there will be no adequate
     remedy at law and that, notwithstanding any other provision of this
     Agreement, in the event of such failure or threatened failure, Purchaser
     and its successors and assigns shall be entitled to injunctive relief and
     to such other and further relief as may be proper and necessary to ensure
     compliance with the provisions of this Section 13.

     14.  COVENANTS OF PURCHASER.

          (a)  PUBLIC ANNOUNCEMENTS.  Prior to the Closing, except as required
     by applicable law, Purchaser shall not, and it shall not permit any
     affiliate or representative to, make any public announcement in respect of
     this Agreement or the transactions contemplated hereby without the prior
     written consent of Seller.

          (b)  NOTICE OF CHANGE.  At all times prior to the Closing, Purchaser
     will, promptly upon becoming aware of such information, notify Seller in
     writing of any fact, condition, event or occurrence that will reasonably be
     likely to result in a failure of any of the conditions contained in
     Sections 10(a), (b) or (c) to be satisfied.

          (c)  FURTHER ACTIONS.  Purchaser agrees to use reasonable good faith
     efforts to take actions and to do those things reasonably necessary, proper
     or advisable to consummate the transactions contemplated hereby by the
     Closing Date.  Subject to the terms and conditions of this Agreement,
     Purchaser shall use commercially reasonable efforts to take, or cause to be
     taken, all actions and to do, or cause to be done, all things necessary,
     proper or advisable to consummate and make effective the transactions
     contemplated by this Agreement.

          (d)  USE OF NAMES.  It is expressly agreed that the Purchaser is not
     purchasing or acquiring any right, title, or interest in any trade names,
     trademarks, logos or service marks employing the words "ObjectSpace" or
     "Voyager" (the "SELLER NAMES").  Except as set forth in the License
     Agreement and as promptly as practicable, but in no event later than three
     months following the Closing Date, the Purchaser shall remove, strike or
     otherwise obliterate all Seller Names from all materials constituting their
     properties and assets, including any buildings, vehicles, business cards,
     schedules, stationery, displays, signs, promotional materials, manuals,
     forms and other materials.

     15.  INDEMNIFICATION.


                                      26
<PAGE>

                                                                    EXHIBIT 2.1

          (a)  SURVIVAL OF REPRESENTATIONS AND WARRANTIES.  All representations
     and warranties made herein by Purchaser or Seller shall survive the
     execution and delivery of this Agreement and, other than the
     representations and warranties contained in Section 7(d), which shall
     survive for the period of the applicable statutes of limitation, shall
     remain in full force and effect for a period of eighteen months following
     the Closing Date, and shall be deemed to have been relied upon by each
     other party hereto, notwithstanding any investigation made by or on behalf
     of such party.  Actions for a breach of a representation or warranty may be
     commenced only during the period in which such representation or warranty
     survives.

          (b)  INDEMNIFICATION BY SELLER.  Seller shall indemnify and hold
     harmless Purchaser and its affiliates and each of their directors,
     officers, employees, advisors, agents and stockholders at all times from
     and after the Closing Date against and with respect to any and all claims,
     demands, lawsuits, proceedings, losses, assessments, taxes, fines,
     penalties, administrative orders, obligations, costs, expenses,
     liabilities, damages, interest, reasonable attorneys' fees and costs of
     investigation (all of the foregoing hereinafter referred to collectively as
     "CLAIMS") which arise or result from and to the extent they are
     attributable to:

               (1)  the Excluded Liabilities and/or the Excluded Assets;

               (2)  the untruth or breach of any representation or warranty made
          by Seller pursuant to this Agreement or any other agreement or
          document executed and delivered by Seller in connection with the
          transactions contemplated hereby;

               (3)  the breach of, or failure to perform, any of the covenants,
          commitments, obligations or agreements on the part of Seller under
          this Agreement or any other agreement or document executed and
          delivered by Seller in connection with the transactions contemplated
          hereby;

               (4)  the operation by Seller of the Business prior to the Closing
          (except with respect to Assumed Liabilities relating to such
          pre-Closing operation); and

               (5)  any and all demands, claims, actions, suits, proceedings,
          assessments, judgments, costs and legal and other expenses incident to
          any of the foregoing.

     Seller shall have no liability with respect to the matters described in
     Sections 15(b)(2), (3) and (5) until the aggregate of all claims for which
     an indemnity would otherwise be payable by Seller exceeds $50,000 in the
     aggregate (the "BASKET"), and in such event, Seller shall be responsible
     only for the amount in excess of the Basket, but in no case shall the
     liability of Seller with respect to the matters described in
     Sections 15(b)(2), (3) and (5) exceed $4,000,000 (the "CAP").  This
     limitation on indemnification, however, will not apply to, and Seller's
     liability shall be unlimited for any breach of any of the Seller's


                                      27
<PAGE>

                                                                    EXHIBIT 2.1

     representations and warranties of which the Seller had knowledge as defined
     in Section 19(f) at any time prior to the date on which such representation
     and warranty is made or any intentional breach by Seller of any covenant or
     obligation pursuant to this Agreement or any other agreement or document
     executed and delivered by Seller in connection with the transactions
     contemplated hereby.

          (c)  INDEMNIFICATION BY PURCHASER.  Purchaser shall indemnify and hold
     harmless Seller and its directors, officers, employees, advisors,
     affiliates, agents and stockholders at all times from and after the Closing
     Date against and with respect to any and all Claims which arise or result
     from and to the extent that are attributable to:

               (1)  the Assumed Liabilities and the Assumed Contracts;

               (2)  the untruth or breach of any representation or warranty made
          by Purchaser pursuant to this Agreement or any other agreement or
          document executed and delivered by Purchaser in connection with the
          transactions contemplated hereby;

               (3)  the breach of, or failure to perform, any of the covenants,
          commitments, obligations or agreements on the part of Purchaser under
          this Agreement or any other agreement or document executed and
          delivered by Purchaser in connection with the transactions
          contemplated hereby;

               (4)  the operation by Purchaser of the Business after the
          Closing;

               (5)  any and all demands, claims, actions, suits or proceedings,
          assessments, judgments, costs and legal and other expenses incident to
          any of the foregoing:

          (d)  PROCEDURES FOR INDEMNIFICATION.  Promptly after receipt by an
     indemnified party pursuant to the provisions of Sections (b) or (c) of this
     Section 15 of notice of a Claim, such indemnified party shall promptly
     notify such indemnifying party of the commencement thereof; but the
     omission to so notify such indemnifying party will not relieve it from any
     liability which it may have to the indemnified party otherwise than
     hereunder unless the indemnified party is materially prejudiced thereby.
     In case such action is brought against an indemnified party and it notifies
     the indemnifying party of the commencement thereof, the indemnifying party
     shall have the right to participate in, and, to the extent that it may
     wish, to assume the defense thereof, with counsel reasonably satisfactory
     to such indemnified party; provided, however, if the defendants in any
     action include both the indemnified party and the indemnifying party and
     the indemnified party shall have reasonably concluded that there may be
     legal defenses available to it which are different from or additional to
     those available to the indemnifying party, or if there is a conflict of
     interest which would prevent counsel for the indemnifying party from also
     representing the indemnified party, the


                                      28
<PAGE>

                                                                    EXHIBIT 2.1

     indemnified party shall have the right to select separate counsel to
     participate in the defense of such action on behalf of such indemnified
     party.  After notice from the indemnifying party to such indemnified
     party of its election so to assume the defense thereof, the indemnifying
     party shall not be liable to the indemnified party pursuant to the
     provisions of such Sections 15(b) or (c) for any legal or other expense
     subsequently incurred by such indemnified party in connection with the
     defense thereof other than reasonable costs of investigation, unless (1)
     the indemnified party shall have promptly employed counsel in accordance
     with the proviso of the preceding sentence, (2) the indemnifying party
     shall not have employed counsel reasonably satisfactory to the indemnified
     party to represent the indemnified party within a reasonable time after
     the notice of the commencement of the action, or (3) the indemnifying
     party has authorized the employment of counsel for the indemnified party
     at the expense of the indemnifying party. No indemnifying party, in the
     defense of any such claim or litigation, shall, except with the consent
     of each indemnified party (such consent not to be unreasonably withheld),
     consent to entry of any judgment or enter into any settlement which does
     not include as an unconditional term thereof the release from all liability
     in respect to such claim or litigation.

          (e)  SOLE REMEDY. This Article 15 is intended to set forth the
     exclusive and entire remedy of Seller and Purchaser against each other in
     respect of any losses that are in the nature of those subject to
     indemnification under this Article 15; the limitations on survival and
     commencement of actions in Section 15(a), the limitations on Seller's
     liability through the Cap and the Basket, and the other provisions of this
     Article 15, are intended to apply to all claims, actions and losses covered
     in substance by this Article 15, regardless of form, whether based on
     contract, tort, statute or any other theory or basis of liability, and
     whether of a legal, equitable or other nature.

     16.  TERMINATION. This Agreement may be terminated at any time prior to the
Closing Date:

          (a)  by the written agreement of Purchaser and Seller;

          (b)  by either Purchaser or Seller by written notice to the other
     party if the transactions contemplated hereby shall not have been
     consummated by 5:00 p.m. Dallas, Texas time on  March 31, 2000, unless such
     date shall be extended by the mutual written consent of Purchaser and
     Seller;

          (c)  by Purchaser by written notice to Seller if (i) a non-curable
     breach of a representation or warranty of Seller occurs that would have a
     material adverse effect on the Purchased Assets or the ability of the
     parties to consummate the transactions contemplated by this Agreement, or
     (ii) any of the conditions set forth in Section 9 shall not have been, or
     if it become apparent that any of such conditions will not be, fulfilled by
     5:00 p.m. Dallas, Texas time on  March 31, 2000, unless such failure shall
     be due to the failure of Purchaser


                                      29
<PAGE>

                                                                    EXHIBIT 2.1

     to perform or comply with any of the covenants, agreements or conditions
     hereof to be performed or complied with by it prior to the Closing; or

          (d)  by Seller by written notice to Purchaser if (i) a non-curable
     breach of a representation or warranty of Purchaser occurs that would have
     a material adverse effect on the Purchased Assets or the ability of the
     parties to consummate the transactions contemplated by this Agreement, or
     (ii) any of the conditions set forth in Section 10 shall not have been, or
     if it become apparent that any of such conditions will not be, fulfilled by
     5:00 p.m. Dallas, Texas time on March 31, 2000, unless such failure shall
     be due to the failure of Seller to perform or comply with any of the
     covenants, agreements or conditions hereof to be performed or complied with
     by it prior to the Closing.

Each party's right of termination under Section 16 is in addition to any other
rights it may have under this Agreement or otherwise, and the exercise of such
right of termination will not be an election of remedies.  If the obligations of
the parties to effect the transactions contemplated by this Agreement are
terminated pursuant to Section 16, all further obligations of the parties under
this Agreement will terminate, except that the obligations in this paragraph of
Section 16, Section 18(a) and Section 19(b) will survive; PROVIDED, HOWEVER,
that if obligations under this Agreement are terminated by a party because of
the breach of the Agreement by the other party or because one or more of the
conditions to the terminating party's obligations under this Agreement is not
satisfied as a result of the other party's failure to comply with its
obligations under this Agreement, the terminating party's right to pursue all
legal remedies will survive such termination unimpaired.

     17.  DISPUTE RESOLUTION.

          (a)  ARBITRATION.  The parties agree that (except as expressly set
     forth herein) all actions, claims, controversies or disputes of any kind
     (E.G. whether in contract or in tort, statutory or common law) ("DISPUTES")
     between them relating, directly or indirectly, to this Agreement or the
     transactions contemplated hereby, whether now existing or hereafter
     arising, are to be resolved by arbitration as provided in this Agreement.
     This agreement to arbitrate will survive the termination of this Agreement.
     All arbitration will be conducted pursuant to and in accordance with the
     following order of priority (1) the terms of this Agreement, (2) the
     Commercial Arbitration Rules of the American Arbitration Association, (3)
     the Federal Arbitration Act and (4) to the extent the foregoing are
     inapplicable, unenforceable or invalid, the laws of the State of Texas.
     The arbitrator used will be selected from impartial arbitrators designated
     by the American Arbitration Association who are familiar with the nature of
     the subject matter of the Dispute.  Any hearing regarding arbitration will
     be held in Dallas, Texas, or at another location mutually acceptable to
     Purchaser and Seller. The arbitrator will use his/her best efforts to
     conduct the arbitration hearing no later than three (3) months from the
     date of the arbitrator's appointment and will use best efforts to render a
     decision within four (4) months from such date.


                                      30
<PAGE>

                                                                    EXHIBIT 2.1

          (b)  DISCOVERY.  Each party may submit in writing to the other party,
     and the other party shall respond to a maximum of any combination of
     thirty-five (35) (none of which may be subparts) of the following:
     interrogatories, demands to produce documents and requests for admissions.
     Each party is also entitled to take the oral deposition of no more than
     five (5) individuals.  Additional discovery may be permitted upon mutual
     agreement of the parties.  The arbitrator will resolve any discovery
     disputes by such pre-hearing conferences as may be needed. All parties
     agree that the arbitrator will have the power of subpoena process as
     provided by law.  Disputes concerning the scope of depositions or document
     production, its reasonableness and enforcement of discovery requests will
     be subject to agreement by the parties or will be resolved by the
     arbitrator.  All discovery requests will be subject to the proprietary
     rights and rights of privilege and other protections granted by applicable
     law to the parties and the arbitrator will adopt procedures to protect such
     rights.  With respect to any Dispute, each party agrees that all discovery
     activities will be expressly limited to matters directly relevant to the
     Dispute and the arbitrator will be required to fully enforce this
     requirement.

          (c)  COURT PROCEEDINGS.  Except for proceedings seeking equitable
     remedies, an arbitration proceeding commenced pursuant to this Section 17
     is a condition precedent to and is a complete defense to the commencement
     of any suit, action or proceeding in any court or before any tribunal with
     respect to any Dispute.  Either party may bring an action in court to
     compel arbitration.  Any party who fails or refuses to submit to binding
     arbitration following demand by the other party shall, if the dispute is
     within the scope of this Section 17, bear all costs and expenses incurred
     by the opposing party in compelling arbitration.

          (d)  RULINGS.  The arbitrator is empowered to resolve Disputes by
     summary rulings substantially similar to summary judgments and motions to
     dismiss.  The arbitrator will resolve all Disputes in accordance with the
     applicable substantive law.  The arbitrator may grant any remedy or relief
     deemed just and equitable and within the scope of this Agreement and may
     also grant such ancillary relief as is necessary to make effective any
     award.

          (e)  FINDINGS OF FACT.  The arbitrator will be required to make
     specific, written findings of fact and conclusions of law, and the parties
     will have the right to appeal or seek vacation or modification of an award
     only (1) if that award is based in whole, or in part, upon fraud or a
     failure to follow the procedures set forth in this Section 17 or (2)  to
     the extent otherwise allowed by applicable law.  Subject to the foregoing,
     the determination of the arbitrator shall be binding on all parties and
     shall not be subject to further review or appeal.  Any judgment upon the
     award rendered by the arbitrator may be entered in any court having
     jurisdiction thereof. The decision of the arbitrator will be enforceable in
     any court of competent jurisdiction.  To the extent permitted by applicable
     law, the arbitrator will have


                                      31
<PAGE>

                                                                    EXHIBIT 2.1

     the power to award recovery of all costs and fees (including attorneys'
     fees, administrative fees, and arbitrators' fees) to the prevailing party.

          (f)  AUTHORITY.  The arbitrator will be limited to interpreting the
     applicable provisions of this Agreement and will not have the authority or
     power to alter, amend, modify, revoke or suspend any condition or provision
     of this Agreement or to create, draft or form a new agreement between the
     parties, or to render an award which, by its terms, has the effect of
     altering or modifying any condition or provision of this Agreement.  The
     arbitrator will have the sole authority to resolve issues regarding whether
     Disputes are subject to arbitration, including the applicability of any
     statute of limitations.

          (g)  EQUITABLE REMEDIES.  No provision of, nor the exercise of any
     rights under, this Agreement will limit the right of any party, during any
     Dispute, to seek, use, and employ ancillary or provisional equitable
     remedies.  Such rights may be exercised at any time except to the extent
     such action is contrary to an award or decision of the arbitrator.  The
     pursuit of provisional or ancillary equitable remedies will not constitute
     a waiver of the right of any party, including the plaintiff, to submit a
     Dispute to arbitration, nor render inapplicable the compulsory arbitration
     provisions of this Section 17.

          (h)  SELECTION OF ARBITRATOR.  The arbitrator will be chosen by mutual
     agreement of Purchaser and Seller.  If they cannot agree within 30 days
     upon the selection of the arbitrator, the arbitrator will be selected by
     the Dallas, Texas office of the American Arbitration Association in
     accordance with its rules and procedures.  Subject to the provisions of
     Section 15 and any other indemnification obligation set forth in this
     Agreement, (1) each party will be responsible for one-half of the expenses
     and fees of the arbitrator and (2) each party will bear its own attorney's
     and expert's fees.

          (i)  OTHER ARBITRATION PROVISIONS.

               (1)  All arbitration proceedings will be conducted in the English
          language and all monetary awards will be denominated in and will be
          payable in United States Dollars.

               (2)  The statute of limitations applicable to any Dispute shall
          be tolled upon the initiation of arbitration under this Agreement and
          shall remain tolled until the arbitration process is completed.

               (3)  Except to the extent necessary to enforce the rights of the
          parties or as required by law, the parties agree to keep confidential
          the existence, content and results of any arbitration proceeding
          conducted pursuant to this Section 17.

     18.  ADDITIONAL AGREEMENTS


                                      32
<PAGE>

                                                                    EXHIBIT 2.1

          (a)  CONFIDENTIAL INFORMATION.  From and after the date of this
     Agreement, Purchaser shall not (and shall take all reasonably necessary
     steps to ensure that its respective officers, directors, employees, agents
     and other representatives do not), without the prior written consent of
     Seller, use, disclose, publish, copy, distribute or furnish to any person
     or entity any list, summary, schedule, description, record, document or
     data storage device, describing, containing, or relating to, or any
     information about, any Seller Confidential Information (as defined below).
     From and after the date of this Agreement, Seller shall not (and shall take
     all reasonably necessary steps to ensure that its respective officers,
     directors, employees, agents and other representatives do not), without the
     prior written consent of Purchaser, use, disclose, publish, copy,
     distribute or furnish to any person or entity any list, summary, schedule,
     description, record, document or data storage device, describing,
     containing, or relating to, or any information about, any Purchaser
     Confidential Information (as defined below).

               (1)  As used herein, "PURCHASER CONFIDENTIAL INFORMATION" shall
          mean,  the various trade secrets and other proprietary and
          confidential information (except as such pertain to the Excluded
          Assets) of the Business which is of a special and unique nature and
          value relating to such matters as, but not limited to, the Business'
          prior business operations, financial affairs, programs, software,
          systems, procedures, manuals, confidential reports and marketing
          methods which consist of compilations of information, records, and
          similar items relating to the Business and included in the Purchased
          Assets.  As used herein, "SELLER CONFIDENTIAL INFORMATION" shall mean,
          with respect to information owned by Seller, any non-public
          information concerning Seller which was obtained by Purchaser in
          connection with the transactions contemplated by this Agreement, other
          than information pertaining to the Purchased Assets.

               (2)  A party's obligations under this Section 18(a) with respect
          to any portion of the Seller Confidential Information or Purchaser
          Confidential Information will terminate if such party can document
          that (i) such confidential information was in the public domain as of
          the date hereof, (ii) such confidential information entered the public
          domain subsequent to the date hereof (but prior to the use or public
          disclosure of such confidential information by the disclosing party)
          through no fault of the disclosing party, or (iii) the communication
          of such confidential information is in response to a valid order by a
          court or other governmental body or was otherwise required by law (but
          only to the extent of such order or requirement).

               (3)  Either party may disclose the terms of this Agreement to
          those its employees who have a need to know such information.


                                      33
<PAGE>

                                                                    EXHIBIT 2.1

               (4)  Seller's obligations under this Section 18(a)(x) will not
          limit Seller's ability to use the Purchaser Confidential Information
          in the normal course of business, consistent with past practices, in
          order to operate the Business from the date hereof through the Closing
          Date and (y) will terminate upon the termination of this Agreement in
          accordance with Article 16.

          (b)  TRANSITION SERVICES.  For three months after the Closing Date,
     Seller shall maintain the information technology systems and support that
     were in effect before the Closing Date that relate solely to electronic
     mail, Internet access, and system accounts related to these services.
     Purchaser shall reimburse Seller for the reasonable cost or reasonable
     allocated share of such information technology systems and support on the
     same basis as it was calculated before the Closing Date.

     19.  MISCELLANEOUS

          (a)  AMENDMENTS AND WAIVER.  This Agreement may be amended only by an
     agreement in writing by the parties hereto.  The failure of any party to
     insist, in any one or more instances, upon performance of any of the terms
     and conditions of this Agreement shall not be construed as a waiver or
     relinquishment of any rights granted hereunder or of the future performance
     of any such term, covenant or condition.  If any provision, clause or part
     of this Agreement, or the application thereof under certain circumstances,
     is held invalid, the remainder of this Agreement, or the application of
     each provision, clause or part under other circumstances, shall not be
     affected thereby.

          (b)  GOVERNING LAW.  THIS AGREEMENT SHALL BE CONSTRUED AND INTERPRETED
     IN ACCORDANCE WITH THE SUBSTANTIVE LAWS OF THE STATE OF CALIFORNIA, WITHOUT
     GIVING EFFECT TO CHOICE OF LAW PRINCIPLES.  TO THE MAXIMUM EXTENT
     PRACTICABLE, THIS AGREEMENT IS PERFORMABLE IN  SANTA CLARA COUNTY,
     CALIFORNIA.

          (c)  NOTICES.  Any notice to be given hereunder shall be deemed given
     and sufficient if either (1) delivered by hand messenger or (2) mailed via
     an overnight "express mail" service with a telecopy being sent within two
     days of such "express mail" notice, in the case of Purchaser, to:

                                   KLA-Tencor
                                   160 Rio Robles
                                   San Jose, CA 95134
                                   Attention: Vice President, General Counsel
                                   Fax: 408-875-2002


                                      34
<PAGE>

                                                                    EXHIBIT 2.1

     with a copy to:               KLA-Tencor
                                   160 Rio Robles
                                   San Jose, CA 95134
                                   Attention: Chief Operating Officer
                                   Fax: 408-875-2002

     or in the case of Seller to:  ObjectSpace, Inc.
                                   14850 Quorum Drive
                                   Suite 500
                                   Dallas, Texas 75240
                                   Attention: David Norris, Chief Executive
                                   Officer
                                   Fax: (972) 726-4200

     with a copy to:               Haynes and Boone, LLP
                                   901 Main Street, Suite 3100
                                   Dallas, Texas 75202-3789
                                   Attention: Gregory R. Samuel, Esq.
                                   Fax: (214) 651-5940

Each party may designate by notice in writing a new address to which any notice,
claim, instruction or communication may thereafter be so given, served or sent.

     (d)  BENEFIT.  This Agreement shall be binding upon and inure to the
benefit of and shall be enforceable by Purchaser and Seller and their respective
successors and permitted assigns.  This Agreement may not be assigned without
the written consent of the other party or parties hereto, except that Purchaser
may assign this Agreement to an affiliate of Purchaser upon written notice to
Seller but any such assignment shall not release Purchaser from its obligations
hereunder.

     (e)  ENTIRE AGREEMENT.  This Agreement, including the schedules and
exhibits attached hereto, constitutes the entire agreement and understanding
among Purchaser and Seller with respect to the sale and purchase of the
Purchased Assets and the other transactions contemplated by this Agreement and
supercedes any prior understandings or written or oral agreements.

     (f)  DEFINITIONS.  The qualification of a statement made in this Agreement
by the phrase "to the knowledge of Seller," "to Seller's knowledge", or a
similar phrase shall indicate that no information that would give any officer,
director or manager of Seller actual knowledge of the inaccuracy of such
statement has come to the attention of any such person, but that such persons
have not undertaken any independent investigation to determine the accuracy of
such statement.

     (g)  BROKERS.  Purchaser and Seller represent and warrant to each other
that there are no brokerage or finder's fees in connection with the transactions
contemplated hereby resulting from any actions taken by them and they hereby
indemnify, save and hold each other harmless from and


                                      35
<PAGE>

                                                                    EXHIBIT 2.1

against any claims by any broker or finder for a fee or expense which is
based in any way on an agreement, arrangement or understanding made or
alleged to have been made by them relating to the transactions contemplated
hereby.

     (h)  DISCLOSURE SCHEDULE.  Disclosure of any fact or item in any Schedule
hereto referenced by a particular paragraph or section in this Agreement shall,
should the existence of the fact or item or its contents be relevant to any
other paragraph or section, be deemed to be disclosed with respect to that other
paragraph or section whether or not an explicit cross-reference appears.

     (i)  COUNTERPARTS.  This Agreement may be executed in multiple
counterparts, each of which will be deemed to be an original and all of which
will be deemed to be a single agreement.

           [The remainder of this page has intentionally been left blank.]




                                      36
<PAGE>

                                                                    EXHIBIT 2.1

     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
executed as of the day, month and year first above written.


                                   KLA-TENCOR CORPORATION


                                   By:  /s/ SAM HARRELL
                                      ---------------------------------------
                                      Name:  Sam Harrell
                                           ----------------------------------
                                      Title:  Senior Vice President
                                            ---------------------------------


                                   OBJECTSPACE, INC.


                                   By:  /s/ DAVID NORRIS
                                      ---------------------------------------
                                      David Norris, Chief Executive Officer


<PAGE>

                                                                     EXHIBIT 2.1

                INDEX OF OMITTED SCHEDULES: A COPY OF ANY OMITTED
                 SCHEDULE MAY BE FURNISHED SUPPLEMENTALLY TO THE
                SECURITIES AND EXCHANGE COMMISSION UPON REQUEST.

1(a)          PERSONAL PROPERTY.

                  Annex A provides a description, location, and fair market
                  value of the personal property acquired.

1(b)          INTELLECTUAL PROPERTY.

                  The schedule lists the specific copyrights, names, and
                  software systems acquired.

1(c)          ASSUMED CONTRACTS.

                  These include contracts entered into with various customers,
                  contractors, partners, government entities, and local
                  suppliers.

1(g)          LICENSES AND PERMITS.

                  None.

2(n)          ADDITIONAL EXCLUDED ASSETS.

                  Annex C identifies the name and type of document excluded from
                  the acquisition.

3(c)          ALLOCATION OF PURCHASE PRICE.

                  Annex D describes the allocation of the purchase price.

4(a)(5)       EMPLOYEE BENEFITS LIABILITY.

                  None.

5(a)          SCHEDULED EMPLOYEES.

                  The schedule lists the names of scheduled employees.

7(b)          CONSENTS.

                  These include the consent of Silicon Valley Bank and the third
                  parties listed in Schedule 7(j).

7(c)          CURRENT BALANCE SHEET.

                  Annex B contains the Balance Sheet current as of December 31,
                  1999.

7(h)          PERMITTED ENCUMBRANCES.

                  The schedule identifies permitted encumbrances.

7(i)          INTELLECTUAL PROPERTY RIGHTS.

                  The schedule describes patents, registered trademarks,
                  agreements relating to intellectual property, and trademark
                  claims.

<PAGE>

                                                                    EXHIBIT 2.1

7(j)          CONTRACTS.

                  The schedule identifies performance issues related to certain
                  contracts and those contracts requiring the consent of third
                  parties to assign the assumed contracts to the Purchaser.

7(m)          MAJOR SUPPLIERS AND CUSTOMERS.

                  The schedule lists the names of major suppliers and customers.

19(g)         BROKERS.

                  Seller designated a broker for the transactions contemplated
                  by the Purchase Agreement.

                                       2