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                                                                Exhibit 10.21(b)

                              AGREEMENT AND RELEASE

      THIS AGREEMENT AND RELEASE (the "Agreement") is entered into as of
December 31, 2002, between General Dynamics Government Systems Corporation
("GSC") and Ezenia! Inc. ("Ezenia!").

                                    RECITALS

      A. Pursuant to an agreement dated as of December 28, 2000 (the "Asset
Purchase Agreement"), Ezenia! purchased certain assets related to the
InfoWorkSpace software program (the "IWS Products") from GSC (the "IWS Sale");

      B. Ezenia! has requested and GSC has agreed to amend the Put Agreement
between them dated as of March 27, 2001 (the "Put Agreement") in order to extend
the time during which Ezenia! is required to purchase its Shares (as defined in
the Put Agreement) back from GSC; and

      C. In consideration for GSC's amendment of the Put Agreement, Ezenia! is
willing to release GSC from liabilities and obligations arising out of the Asset
Purchase Agreement, as set forth herein.

      NOW THEREFORE, in consideration of the promises set forth herein and for
other good and valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, the parties agree as follows:

1.   AMENDMENT TO PUT AGREEMENT.

(a)  Section 2 of the Sale of Licenses and Amendment to Put Agreement dated
September 27, 2001 between GSC and Ezenia! is deleted in its entirety. Section 1
of the Put Agreement between Ezenia! and GSC dated March 27, 2001 (the "Put
Agreement") is deleted in its entirety and replaced with the following text:

               1. GRANT OF PUT RIGHT. At any time during the period of thirty
          (30) consecutive days beginning on March 31, 2004 with respect to
          290,000 Shares, GSC will have the right (the "Put Right") to elect to
          sell the Shares to the Company, and the Company will be required to
          purchase such Shares from GSC, at a purchase price per Share equal to
          the Purchase Price (as defined below); provided, however, that the Put
          Right will expire at such time as the last reported closing price of
          the Common Stock on the NASDAQ National Market (or such national
          securities exchange on which the Common Stock may then be listed), has
          been equal to or greater than $11.00 per share for fifteen (15)
          consecutive trading days.

(b)  Section 3 of the Put Agreement is deleted in its entirety and replaced with
the following text:

             3. EXERCISE OF PUT RIGHT; CLOSING OF SALE. In order to exercise a
          Put Right, GSC will deliver written notice of such exercise to the
          Company.

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          The closing of the purchase and sale of Shares pursuant to this
          Agreement will take place within thirty (30) days following the
          Company's receipt of such notice. In the event that any such closing
          of the purchase and sale of Shares pursuant to this Agreement does not
          take place during such 30-day period due to the Company's
          unwillingness or inability to do so other than as a result of a
          default by GSC (a "Company Default"), then the parties agree and
          stipulate that, at the expiration of such 30-day period, and in
          addition to any other remedy available to GSC at law or in equity, for
          so long as the Purchase Price remains unpaid, the Company will forego
          and hereby waives all of its rights in connection with any payment due
          and owing from GSC under any agreement between the parties (including
          without limitation license fees), and including without limitation all
          rights to receive such payments or to demand or collect any such
          payments or to pursue any claim, action or suit to recover any such
          payments, for so long as, and to the extent of, any amount due GSC as
          a result of a Company Default remains unpaid, it being understood that
          (i) the Company is entitled to payment and recovery of any such amount
          in the absence of and/or upon the cure or satisfaction of any Company
          Default, and (ii) any applicable fees payable with respect to the
          License (as defined in Section 14(b) of the Development Agreement)
          will continue to accrue during such period but not be payable unless
          or until the absence of and/or upon the cure or satisfaction of any
          Company Default..

2.   AMENDMENT TO THE RESELLER AGREEMENT.

(a)  The following text is added as new Section 29 of the Reseller Agreement
between GSC and Ezenia! dated as of March 27, 2001 (the "Reseller Agreement"):

              29. PUT AGREEMENT. Notwithstanding any provision to the contrary
                  in this Agreement, the Reseller and the Vendor agree and
                  stipulate that any and all fees due and payable to the Vendor
                  by the Reseller hereunder (including without limitation,
                  license fees), whether during the term of this Agreement or
                  post-termination, will be subject to the last sentence of
                  Section 3 of the Put Agreement, as amended, except that the
                  foregoing provision will be read so that the word "Vendor"
                  will be substituted for the word "Company" and the word
                  "Reseller" will be substituted for "GSC."

(b)  Section 2 of the Reseller Agreement is deleted in its entirety and replaced
with the following text:

               2. TERM OF AGREEMENT. The term of this Agreement will commence on
                  the Effective Date and, unless terminated by either Party as
                  set forth in this Agreement, will remain in full force and
                  effect until the earlier of (a) seven (7) years after the
                  Effective Date, or (b) the effective date of termination of
                  the InfoWorkSpace(TM) Software Development Agreement dated
                  March 27, 2001 between Vendor and Reseller.

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3.   AMENDMENT TO THE DEVELOPMENT AGREEMENT.

     (a) Section 13(d) of the InfoWorkSpace Software Development Agreement
between GSC and Ezenia! dated as of March 27, 2001 (the "Development Agreement")
is amended by adding the following text at the end of that section:

               This Agreement is to be interpreted in accordance with Section
               365(n) of the Bankruptcy Code. It is understood and agreed that
               the licensed matter hereunder is intellectual property as defined
               in Section 101(35A) of the Bankruptcy Code and that Section
               365(n) shall govern this Agreement in the event that the
               Purchaser files or has filed against it a bankruptcy case.

(b)  The following text is added as new Section 27 to the Development Agreement

               27. PUT AGREEMENT CONDITIONS. Notwithstanding any provision to
                   the contrary in this Agreement, the Seller and the Purchaser
                   agree and stipulate that any and all fees due and payable to
                   the Purchaser by the Seller hereunder (including without
                   limitation, license fees), whether during the term of this
                   Agreement or post-termination, will be subject to the last
                   sentence of Section 3 of the Put Agreement, as amended,
                   except that the foregoing provision will be read so that the
                   word "Purchaser" will be substituted for the word "Company"
                   and the word "Seller" will be substituted for "GSC."

(c)  The following text is added as new Section 28 to the Development Agreement:

                   28. SOURCE CODE ESCROW. Upon execution of the escrow
                   agreement referenced below, Purchaser agrees to deposit and
                   maintain thereafter in escrow a copy of the most up-to-date
                   source code for the Products (in both human- and
                   machine-readable form), and all releases, updates, revisions,
                   improvements, enhancements, and other changes thereto within
                   thirty (30) days after they become generally commercially
                   available (hereafter collectively referred to as the "Program
                   Documentation"). For the avoidance of doubt, "Program
                   Documentation" shall not include any third party software or
                   materials. The deposit in escrow shall be administered by a
                   law firm (which may be outside counsel to Seller) or an
                   institutional escrow agent in accordance with an escrow
                   agreement to be mutually agreeable to the parties. Subject to
                   the release conditions specified below, Seller shall only
                   have access to the Program Documentation as is reasonably
                   necessary to enable Seller to use the Program Documentation
                   in accordance with and for the purposes specified in and
                   pursuant to the License (as such term is defined in Section
                   14(b)). The cost of entering into and maintaining this escrow
                   arrangement shall be borne by Seller. The escrow agreement
                   will provide, subject to its terms and conditions, that the
                   escrowed materials will be released (a) to the Seller upon
                   the occurrence of a Company Default (under and as defined in
                   the Put Agreement) that is not cured within the applicable
                   thirty (30) day cure period or a For-Cause Termination

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                   under Section 14(b) of this Agreement, and (b) to the
                   Purchaser upon termination or expiration of this Agreement
                   (other than a For-Cause Termination).

(d)  The first sentence of Section 14(b) of the Development Agreement is deleted
in its entirety and replaced with the following text:

               Subject to the terms and conditions hereof, including without
               limitation, the last sentence of Section 3 of the Put Agreement,
               Purchaser hereby grants to Seller a non-exclusive, worldwide,
               transferable license (with the right to sublicense) (the
               "License") to use, make, have made, offer to sell, sell, and
               import the Products (as defined in the Reseller Agreement and the
               Development Agreement, any conflict between definitions in the
               two agreements being resolved in favor of the broadest possible
               interpretation; provided that notwithstanding anything to the
               contrary herein, in every respect and in all instances, third
               party content and products is/are excluded from "Products" and
               the License hereunder), as well as to exercise all rights under
               Purchaser's copyright(s) in, the Products and the Program
               Documentation (as defined in Section 28 hereof), for itself, its
               customers and its sublicensees for any and all purposes
               contemplated in this Agreement and in the Reseller Agreement;
               provided that, although this license is granted as of the date of
               this Agreement, as amended, Seller agrees that it shall not use
               or otherwise exercise the License unless and until the earlier to
               occur of: (i) the termination of this Agreement by Seller
               pursuant to subsections 13(b), (c), (d), (e), or (f) (a
               "For-Cause Termination"), or (ii) the occurrence of a Company
               Default (as defined in the Put Agreement) which is not cured
               within the applicable thirty (30) day cure period, and only for
               so long as such Company Default remains uncured. No further
               actions shall be required by Seller or Purchaser to make this
               license effective.

(e)  The fourth sentence of Section 14(b) of the Development Agreement is
amended by adding the following language to the beginning of the sentence:
"Subject to the last sentence of Section 3 of the Put Agreement,".

4.   RELEASE.

(a)  For and in consideration of GSC's agreement to amend the Put Agreement as
set forth herein, and other good and valuable consideration paid to and/or
realized, directly or indirectly, tangibly or intangibly, by Ezenia!, the
receipt and sufficiency of which are hereby acknowledged, Ezenia!, its
successors and assigns (collectively, the "Releasors"), do hereby remise,
release and forever discharge GSC and its Affiliates (as defined in the Asset
Purchase Agreement) and their respective successors and assigns (collectively,
the "Releasees") of and from any and all manner of all liabilities, obligations,
action and actions, cause and causes of action, suits, claims and demands of any
kind and nature whatsoever in law or in equity (whether actual or contingent,
liquidated or unliquidated, asserted or unasserted, known or unknown), which the
Releasors, or any of them, now has, has ever had or may ever have against any or
all of the Releasees, under or in connection with the IWS Sale, the Asset
Purchase Agreement or the Closing Agreement between GSC and Ezenia! executed as
of March 27, 2001, but excluding

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Sections 7.5, 7.6, 8.1 and 8.2 of the Asset Purchase Agreement, the Reseller
Agreement, as amended, the Put Agreement, as amended, the Development Agreement,
as amended, and the other Ancillary Documents (as defined in the Asset Purchase
Agreement).

(b)  Each of the parties hereto acknowledges and agrees that the release
contained in this Section 4 is intended to constitute a full release and
discharge with respect to all unknown claims of the types described therein, and
Ezenia! hereby covenants and agrees not to raise any equitable or legal claim or
defense, including any claim or defense as to the invalidity and
unenforceability of such release with respect to any such unknown claims.

5.   MISCELLANEOUS.

(a)  AMENDMENTS. The provisions of this Agreement may be amended or waived only
by a written agreement executed and delivered by Ezenia! and GSC. No other
course of dealing between the parties to this Agreement or any delay in
exercising any rights hereunder will operate as a waiver of any rights of such
parties.

(b)  SUCCESSORS AND ASSIGNS. Neither party may assign or delegate any of its
rights or obligations under or in connection with this Agreement without the
written consent of the other party; provided that GSC may without the written
consent of Ezenia! assign its rights under this Agreement to any of its
Affiliates; provided that with respect to any right or obligation under Section
1, 2(b), 3, 4 or 5, such Affiliate must otherwise meet all of Ezenia!'s usual
and customary requirements for qualifying as a reseller of the Products under
the Reseller Agreement; and further provided that either party may assign its
rights without the consent of the other party to any purchaser of substantially
all of the assets or, in Ezenia!'s case, the capital stock of such party. Except
as otherwise expressly provided herein, all covenants and agreements in this
Agreement by or on behalf of any of the parties hereto will be binding upon and
enforceable against the respective successors and assigns of such party and will
be enforceable by and will inure to the benefit of their respective successors
and permitted assigns.

(c)  SEVERABILITY. Whenever possible, each provision of this Agreement will be
interpreted in such manner as to be effective and valid under applicable law,
but if any provision of this Agreement is held to be prohibited by or invalid
under applicable law, such provision will be ineffective only to the extent of
such prohibition or invalidity, without invalidating the remainder of this
Agreement.

(d)  COUNTERPARTS. This Agreement may be executed simultaneously in two or more
counterparts, any one of which need not contain the signatures of more than one
party, but all such counterparts taken together will constitute one and the same
Agreement.

(e)  NO THIRD-PARTY BENEFICIARIES. This Agreement will not confer any rights or
remedies upon any person other than Ezenia! and GSC and their respective
successors and permitted assigns; provided that to the extent there are any
third party beneficiaries to the Reseller Agreement or the Development
Agreement, such third parties are intended third party beneficiaries of this
Agreement to the extent that, and only with respect to, such portions hereof as
constitute an amendment to the Reseller Agreement or Developer Agreement, as
applicable.

(f)  ENTIRE AGREEMENT. This Agreement, the Put Agreement, the Development
Agreement, and the Reseller Agreement, each as amended hereby, constitute the
entire agreement between

                                        5
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the parties regarding the subject matter covered herein, and supersedes any
prior understandings, agreements or representations by or among the parties,
written or oral, that may have related to the same subject matter hereof.

(g)  GOVERNING LAW. ALL QUESTIONS CONCERNING THE CONSTRUCTION, VALIDITY AND
INTERPRETATION OF THIS AGREEMENT WILL BE GOVERNED BY THE INTERNAL LAW, AND NOT
THE LAW OF CONFLICTS, OF THE STATE OF DELAWARE.

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     IN WITNESS WHEREOF, each of the parties hereto has caused this Agreement
and Release to be executed by a duly authorized officer as of the date first
above written.

                                      EZENIA! INC.

                                      By:  /s/ Khoa D. Nguyen
                                          -------------------------------------
                                          Name: Khoa D. Nguyen
                                          Title: Chief Executive Officer

                                      GENERAL DYNAMICS GOVERNMENT
                                      SYSTEMS CORPORATION

                                      By:  /s/ Michael W. Kauffman
                                          -------------------------------------
                                          Name: Michael W. Kauffman
                                          Title: Asst. Secretary

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EXHIBIT (10)(p)    
  

 
  FIRST AMENDMENT TO THE AGREEMENT AND PLAN OF MERGER    
  

        This First Amendment to the Agreement and Plan of Merger ("First Amendment") is entered into as of November 27, 2001, among International Bancshares
Corporation, a Texas corporation ("Parent"), NBC Acquisitions Corp., a Delaware corporation and a direct wholly-owned subsidiary of Parent ("Delaware Sub"), and National Bancshares Corporation of
Texas, a Texas corporation (the "Company"). 

 
 

W I T N E S S E T H:    
  

        WHEREAS, Parent, the Company and NBC Acquisition Corp, a Texas corporation and predecessor in interest to Delaware Sub ("Texas Sub"), entered into that certain
Agreement and Plan of Merger dated as of July 30, 2001 (the "Merger Agreement"), providing for, among other things, (i) a tender offer (the "Offer") by Texas Sub to purchase all of the
outstanding shares of common stock, par value $0.001 per share, of the Company (the "Shares"), at a price per Share equal to the Merger Consideration (as defined in the Merger Agreement), without
interest, and (ii) subject to the satisfaction of certain conditions set forth in the Merger Agreement, the merger (the "Merger") of Texas Sub with and into the Company, with the Company as the
surviving corporation in the Merger; 

        WHEREAS,
on or about November 20, 2001, Texas Sub merged with and into Delaware Sub, with Delaware Sub as the surviving corporation in such merger; 

        WHEREAS,
the parties desire to amend the Merger Agreement upon the terms set forth herein; and 

        WHEREAS,
capitalized terms not otherwise defined herein shall have the meaning ascribed thereto in the Merger Agreement; 

        NOW,
THEREFORE, in consideration of the premises and mutual covenants and agreements of the Parties hereinafter contained, the Parties hereby agree as follows: 

        1.    Effective Time of the Merger.    Section 1.4 of the Merger Agreement is hereby amended and restated to
read in its entirety as follows: 

        1.4  Effective Time of the Merger.    The Merger shall become effective at the date and time (the "Effective Time")
when Articles of Merger meeting the requirements of the Texas Business Corporation Act (the "TBCA") and a Certificate of Merger meeting the requirements of the Delaware General Corporation Law (the
"DGCL") shall have been duly executed and filed in accordance with the TBCA and the DGCL, respectively, or at such other time as is specified in such Articles of Merger in accordance
with the TBCA and such Certificate of Merger in accordance with the DGCL, which Articles of Merger and Certificate of Merger shall be filed as soon as practicable following fulfillment of the
conditions set forth in Article VII hereof. 

        2.    Articles of Incorporation.    Section 2.1 of the Merger Agreement is hereby amended and restated to read
in its entirety as follows: 

        2.1  Articles of Incorporation.    The Articles of Incorporation of the Company, as in effect immediately prior to
the Effective Time, shall be the Articles of Incorporation of the Surviving Corporation, until further amended in accordance with their terms and as provided by law and this Agreement. 

1

 

        3.    By-laws.    Section 2.2 of the Merger Agreement is hereby amended and restated to read in its
entirety as follows: 

        2.2  By-laws.    The By-laws of the Company, as in effect immediately prior to the Effective
Time, shall be the By-laws of the Surviving Corporation, and thereafter may be amended in accordance with their terms and as provided by law and this Agreement. 

        4.    Effects of Merger.    Section 2.4 of the Merger Agreement is hereby amended and restated to read in its
entirety as follows: 

        2.4  Effects of Merger.    The Merger shall have the effects set forth in the TBCA and the DGCL. 

        5.    Counterparts.    This First Amendment may be executed in one or more counterparts, all of which taken together
shall constitute one instrument. 

        6.    Miscellaneous.    Except as otherwise expressly set forth in this First Amendment, the Merger Agreement shall
remain in full force and effect, and the parties hereto shall be bound by the terms and conditions thereof, as herein amended. 

[REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]

2

 

        IN
WITNESS WHEREOF, the undersigned have duly executed this First Amendment as of the date and year first above written. 

	 	 	INTERNATIONAL BANCSHARES CORPORATION
	

 	
 	

By:	

/s/  DENNIS E. NIXON      
 Dennis E. Nixon, President
	

 	
 	

NBC ACQUISITIONS CORP.
	

 	
 	

By:	

/s/  DENNIS E. NIXON      
 Dennis E. Nixon, President
	

 	
 	

NATIONAL BANCSHARES CORPORATION OF TEXAS
	

 	
 	

By:	

/s/  MARVIN E. MELSON      
 Marvin E. Melson, President

3

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EXHIBIT (10)(p)

FIRST AMENDMENT TO THE AGREEMENT AND PLAN OF MERGER

W I T N E S S E T H

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