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Exhibit 4.3    
    


 
  GUARANTEE    
    


        The Guarantors listed below (hereinafter referred to as the "Guarantors," which term includes any successors or assigns under the Indenture, dated May 15,
2003 (the "Indenture"), among the Guarantors party thereto, the Company (as defined below) and Deutsche Bank Trust Company Americas, as trustee (the "Trustee"), and any additional Guarantors), have
jointly and severally, irrevocably and unconditionally guaranteed on an unsecured senior subordinated basis the Guarantee Obligations (as defined in Section 10.1 of the Indenture), which
include (i) the due and punctual payment of the principal of, premium, if any, and interest (and Liquidated Damages, if any) on the 8% Senior Subordinated Notes due 2011 (the "Notes") of The
Titan Corporation, a Delaware corporation (the "Company"), whether at maturity, by acceleration, call for redemption, upon a Change of Control Offer, upon an Asset Sale Offer or otherwise, and the
prompt payment of interest on the overdue principal and premium, if any, and (to the extent permitted by law) interest on any interest on the Notes, and all other payment Obligations of the Company,
to the Holders or the Trustee all in accordance with the terms set forth in Article X of the Indenture, and (ii) in case of any extension of time of payment or renewal of any Notes or
any such other Obligations, the prompt payment in full of such Notes or other Obligations when due in accordance with the terms of the extension or renewal, whether at stated maturity, by
acceleration, call for redemption, upon a Change of Control Offer, upon an Asset Sale Offer, or otherwise, subject in the case of clauses (i) and (ii) above, to the limitations set forth
in Section 10.5 of the Indenture. 


        The
obligations of each Guarantor to the Holders and to the Trustee pursuant to this Guarantee and the Indenture are expressly set forth in Article X of the Indenture and
reference is hereby made to such Indenture for the precise terms of this Guarantee. 


        The
obligations of each Guarantor to the Holders and to the Trustee pursuant to this Guarantee and the Indenture are expressly subordinated to Senior Debt of the Guarantor as set forth
in Section 10.7 of the Indenture and reference is hereby made to such Section for the precise terms of such subordination. 


        No
past, present or future director, officer, employee, incorporator or stockholder (direct or indirect) of the Guarantors (or any such successor entity), as such, shall have any
liability for any obligations of the Guarantors under this Guarantee or the Indenture or for any claim based on, in respect of, or by
reason of, such obligations or their creation, except in their capacity as an obligor or Guarantor of the Notes in accordance with the Indenture. 


        This
is a continuing Guarantee and shall remain in full force and effect and shall be binding upon each Guarantor and its successors and assigns until full and final payment of all of
the Company's obligations under the Notes and Indenture or until released or legally defeased in accordance with the Indenture and shall inure to the benefit of the successors and assigns of the
Trustee and the Holders, and, in the event of any transfer or assignment of rights by any Holder or the Trustee, the rights and privileges herein conferred upon that party shall automatically extend
to and be vested in such transferee or assignee, all subject to the terms and conditions hereof. This is a Guarantee of payment and performance and not of collectibility. 


        This
Guarantee shall not be valid or obligatory for any purpose until the certificate of authentication on the Note upon which this Guarantee is noted shall have been executed by the
Trustee under the Indenture by the manual signature of one of its authorized officers. 



        The
obligations of each Guarantor under this Guarantee shall be limited to the extent necessary to insure that it does not constitute a fraudulent conveyance under applicable law. 


        THE
TERMS OF ARTICLE X AND XI OF THE INDENTURE ARE INCORPORATED HEREIN BY REFERENCE. 


        Capitalized
terms used herein have the same meanings given in the Indenture unless otherwise indicated. 






        IN
WITNESS WHEREOF, each of the Guarantors has caused this instrument to be duly executed. 



	Dated: May 15, 2003	 	THE TITAN CORPORATION
	

 	
 	

By:	

/s/  MARK W. SOPP      
	 	 	 	
 Name:

Title:
	

 	
 	

ACS TECHNOLOGIES, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

ATLANTIC AEROSPACE ELECTRONICS CORPORATION
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

AVERCOM CORPORATION
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

BTG, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

BTG TECHNOLOGY RESOURCES, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

BTG TECHNOLOGY SYSTEMS, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

BTG SYSTEMS ENGINEERING, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	 	 	 	 







	

 	
 	

C&N ENTERPRISES, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

CALIFORNIA TUBE LABORATORY, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

CAYENTA EUTILITY SOLUTIONS—EMUNICIPAL SOLUTIONS, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

CAYENTA OPERATING LLC
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

CONCEPT AUTOMATION, INC. OF AMERICA
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

DATACENTRIC AUTOMATION CORPORATION
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

DBA SYSTEMS, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

DELFIN SYSTEMS
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	 	 	 	 







	

 	
 	

DELTA CONSTRUCTION MANAGEMENT, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

GLOBALNET, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

GLOBALNET INTERNATIONAL, LLC
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

HORIZONS SERVICES COMPANY, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

INTERMETRICS INTERNATIONAL, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

INTERMETRICS SECURITIES, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

INTERNATIONAL SYSTEMS, LLC
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

JAYCOR, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	 	 	 	 







	

 	
 	

LINCOM CORPORATION
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

LINCOM WIRELESS, LLC
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

LINKABIT WIRELESS LLC
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

MICROLITHICS CORPORATION
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

MIDNIGHT OIL SERVICES, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

MJR ASSOCIATES, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

NATIONS, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

PROCOM SERVICES, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	 	 	 	 







	

 	
 	

PROGRAM SUPPORT ASSOCIATES, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

PULSE ENGINEERING, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

PULSE SCIENCES, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

RW CONSULTANTS, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

RESEARCH PLANNING, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

SENCOM CORPORATION
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

STAC, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

TITAN AFRICA, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	 	 	 	 







	

 	
 	

TITAN SCAN TECHNOLOGIES CORPORATION
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

TITAN VIGIL, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

TITAN WIRELESS AFRIPA HOLDINGS, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

TITAN WIRELESS, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

TOMOTHERAPEUTICS, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

UNIDYNE, LLC
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

UNIVISION TECHNOLOGIES, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

VISICOM LABORATORIES, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:
	

 	
 	

WAVESCIENCES, INC.
	

 	
 	

By:	

/s/  CHERYL L. BARR      
	 	 	 	
 Name:

Title:













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Exhibit 4.3


GUARANTEE