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                                                                   EXHIBIT 10.23

             THIRD AMENDMENT TO AMENDED AND RESTATED LOAN AGREEMENT
                            DATED JUNE 28, 2002 AMONG
           DYNAMICS RESEARCH CORPORATION, DRC METRIGRAPHICS, INC., DRC
         SOFTWARE, INC.,DRC TELECOM, INC., DYNAMICS RESEARCH INVESTMENT
              CORPORATION, DRC INTERNATIONAL CORPORATION, H.J. FORD
                    ASSOCIATES, INC. AND ANDRULIS CORPORATION
                                       AND
           BROWN BROTHERS HARRIMAN & CO., AS ADMINISTRATIVE AGENT AND
         LENDER, BANKNORTH, N.A., AS DOCUMENTATION AGENT AND LENDER, AND
           KEY CORPORATE CAPITAL INC., AS SYNDICATION AGENT AND LENDER

         This Third Amendment to Amended and Restated Loan Agreement
(hereinafter, this "Amendment") is made as of the 23rd day of December, 2003
by and among DYNAMICS RESEARCH CORPORATION, DRC METRIGRAPHICS, INC., DRC
SOFTWARE, INC., DRC TELECOM, INC., DYNAMICS RESEARCH INVESTMENT CORPORATION, DRC
INTERNATIONAL CORPORATION, H. J. FORD ASSOCIATES, INC., AND ANDRULIS
CORPORATION, each of which is a Massachusetts corporation (other than H.J. Ford
Associates, Inc. and Andrulis Corporation which are Delaware corporations) with
their principal executive offices at 60 Frontage Road, Andover, Massachusetts
(hereinafter, individually and collectively, jointly and severally, the
"Borrowers") and BROWN BROTHERS HARRIMAN & CO., as administrative agent and as a
lender, BANKNORTH, N.A., as documentation agent and as a lender, and KEY
CORPORATE CAPITAL INC., as syndication agent and as a lender (hereinafter,
individually and collectively, the "Lenders"), in consideration of the mutual
covenants contained herein and the benefits to be derived herefrom. Unless
otherwise specified herein, all capitalized terms used herein shall have the
same meaning as set forth in the Credit Agreement (as defined hereinbelow).

                              W I T N E S S E T H:

         WHEREAS, the Borrowers executed and delivered to the Lenders a certain
Amended and Restated Loan Agreement dated June 28, 2002, as amended by a certain
Amendment dated December 16, 2002, and a certain Second Amendment dated as of
March 26, 2003 (hereinbefore and hereinafter, as amended, the "Credit
Agreement") pursuant to which, among other things, the Lenders extended in favor
of the Borrowers a Revolving Credit in the maximum principal amount of
$50,000,000.00 and a Term Loan in the maximum principal amount of
$10,000,000.00; and

         WHEREAS, the Borrowers have requested that the Lenders (i) amend the
Capital Expenditure restrictions set forth in Section 7-30 of the Credit
Agreement, and (ii) otherwise modify the terms and conditions of the Credit
Agreement as set forth herein; and

         WHEREAS, the Lenders have indicated their willingness to do so, BUT
ONLY on the terms and conditions contained in this Amendment; and

         WHEREAS, the Borrowers have determined that this Amendment is in the
Borrowers' respective best interests.

         NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto agree as
follows:

         1.       Amendment to the Credit Agreement.

                  (a)      Section 7-30 of the Credit Agreement is hereby
         amended by deleting same in its entirety and substituting the following
         Section 7-30 therefor:

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                  "7-30.   Capital Expenditures. None of the Borrowers will, nor
                  will any Borrower permit any Subsidiary to, make any Capital
                  Expenditures during any fiscal year of the Lead Borrower
                  unless the aggregate amount of all Capital Expenditures made
                  or committed to be made by all Borrowers and their respective
                  Subsidiaries in such fiscal year does not exceed $9,000,000 in
                  fiscal year 2003, $7,000,000 in fiscal year 2004, or
                  $6,000,000 in any fiscal year thereafter."

         2.       Fees. Upon the execution of this Amendment, the Borrowers
shall be liable to the Lenders for an amendment fee in the amount of $5,000.00
(the "Amendment Fee"). The Amendment Fee shall (i) be paid to the Administrative
Agent concurrently with the execution and delivery of this Amendment by the
Borrowers, (ii) be deemed fully earned as of the date hereof, and (iii) in all
events, constitute a fee and shall not be applied in reduction of any of the
other Liabilities of the Borrowers. Upon the Administrative Agent's receipt of
the Amendment Fee, the Amendment Fee shall be distributed to the Lenders on a
pro rata basis.

         3.       Conditions to Effectiveness. This Amendment shall become
effective upon receipt by the Administrative Agent of (i) this fully executed
Amendment bearing the original signatures of each Borrower and each Lender, and
(ii) the Amendment Fee.

         4.       Representations; No Events of Default. The Borrowers hereby
certify to the Lenders that, to the best of the Borrowers' knowledge and belief
after due inquiry, the representations and warranties contained in the Credit
Agreement, as modified by this Amendment, are true as of the date hereof and
that, after the effectiveness of this Amendment, no Event of Default has
occurred and is continuing under the Credit Agreement or any document executed
in connection therewith.

         5.       Incorporation of Discussions; Modifications. This Amendment
and all other documents, instruments or agreements executed in connection
herewith incorporate all discussions and negotiations between the Borrowers and
the Lenders, either expressed or implied, concerning the matters included
herein, any statute, custom, or usage to the contrary notwithstanding. No such
discussions or negotiations shall limit, modify or otherwise affect the
provisions hereof. No modification, amendment, or waiver of any provision of
this Amendment or the Credit Agreement or any provision under any other
agreement, document or instrument between the Borrowers and the Lenders shall be
effective unless executed in writing by the party to be charged with such
modification, amendment or waiver, and if such party be the Lenders, then by a
duly authorized officer of each Lender.

         6.       Ratification of Credit Agreement. Except as specifically
modified herein, the Credit Agreement shall remain in full force and effect as
originally written and the Borrowers hereby ratify and confirm all terms and
conditions contained therein and further ratify and reaffirm all representations
and warranties made therein as of the date hereof.

         7.       Governing Law. This Amendment shall be construed in accordance
with and governed by the laws of the Commonwealth of Massachusetts and shall
take effect as a sealed instrument.

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         IN WITNESS WHEREOF, the parties have hereunto set their hands and seals
as of the date first written above.

                                   DYNAMICS RESEARCH CORPORATION

                                   By:____________________________

                                   Title: ________________________

                                   DRC METRIGRAPHICS, INC.

                                   By:____________________________

                                   Title: ________________________

                                   DRC SOFTWARE, INC.

                                   By:____________________________

                                   Title: ________________________

                                   DRC TELECOM, INC.

                                   By:____________________________

                                   Title: ________________________

                                   DYNAMICS RESEARCH INVESTMENT CORPORATION

                                   By:____________________________

                                   Title: ________________________

                                   DRC INTERNATIONAL CORPORATION

                                   By:____________________________

                                   Title: ________________________

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                                   H.J. FORD ASSOCIATES, INC.

                                   By:____________________________

                                   Title:_________________________

                                   ANDRULIS CORPORATION

                                   By:____________________________

                                   Title:_________________________

        ACKNOWLEDGED AND AGREED:

        BROWN BROTHERS HARRIMAN & CO.,
        as administrative agent and as a lender

        By:______________________________________

        Name:____________________________________

        Title:___________________________________

        BANKNORTH, N.A.,
        as documentation agent and as a lender

        By:______________________________________

        Name:____________________________________

        Title:___________________________________

        KEY CORPORATE CAPITAL INC.,
        as syndication agent and as a lender

        By:______________________________________

        Name:____________________________________

        Title:___________________________________

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