FIRST AMENDMENT TO FOURTH AMENDED AND RESTATED LOAN AGREEMENT

This First Amendment to Fourth Amended and Restated Loan Agreement (this “ First Amendment ”) is made as of the 31 day of December, 2008, by and among

Brown Brothers Harriman & Co., as Administrative Agent (hereinafter, the “ Administrative Agent ”), a general partnership organized under the laws of the State of New York with offices at 40 Water Street, Boston, Massachusetts 02109; and

TD Bank, N.A., as Documentation Agent (hereinafter, the “ Documentation Agent ”) a national banking association with offices at 7 New England Executive Park, Burlington, Massachusetts 01803; and

Bank of America, N.A., as Syndication Agent (hereinafter, the “ Syndication Agent ”), and, together with the Administrative Agent and the Documentation Agent, the “ Agents ”), a national banking association with offices at 100 Federal Street, Boston, Massachusetts 02110,

as Agents on behalf of Brown Brothers Harriman & Co., TD Bank, N.A., Bank of America, N.A., and the other financial institutions which may hereafter become lenders to the Loan Agreement (as defined below) (each such party a “ Lender ” and collectively the “ Lenders ”),

and

Dynamics Research Corporation (hereinafter, the “ Lead Borrower ”), a Massachusetts corporation, with its principal executive offices at 60 Frontage Road, Andover, Massachusetts, as agent for itself and each of

DRC International Corporation (“ International ”), a Massachusetts corporation with its principal executive offices at 60 Frontage Road, Andover, Massachusetts;

H.J. Ford Associates, Inc. (“ H.J. Ford ”), a Delaware corporation with its principal executive offices at 60 Frontage Road, Andover, Massachusetts; and

Kadix Systems, LLC (“ Kadix ”), a Virginia limited liability company with its principal executive offices at 60 Frontage Road, Andover, Massachusetts.

(Each of the Lead Borrower, International, H.J. Ford, and Kadix being sometimes hereinafter referred to individually as a “ Borrower ” and collectively as the “ Borrowers ”).

WHEREAS, the Borrowers, the Lenders and the Agents are parties to a certain Fourth Amended and Restated Loan Agreement dated as of August 1, 2008 (as may be amended and in effect from time to time, the “ Loan Agreement ”);

WHEREAS, the Borrowers have requested that the parties hereto amend the Loan Agreement to modify certain provisions of the Loan Agreement; and

WHEREAS, the Agents and the Lenders each agree to modify and amend certain provisions of the Loan Agreement, subject to the terms and conditions set forth herein;

NOW THEREFORE, as an additional inducement for the Lenders to maintain the credit facilities on the terms and conditions set forth in the Loan Agreement as amended hereby, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, each of the Borrowers herby covenant and agree with the Agents and the Lenders as follows:

““ 2008 Reserve ”: is defined in Section 8-10.

“ EBITDA ”: for any period, the Consolidated Net Income of the Lead Borrower and its Subsidiaries for such period adjusted by adding back thereto amounts deducted in computing such Consolidated Net Income in respect of each of (a) Consolidated Interest Expense, (b) provision for taxes in respect of income and profits of the Lead Borrower and its Subsidiaries, (c) depreciation and amortization of the Lead Borrower and its Subsidiaries, and (d) other non-cash expenses incurred pursuant to employee equity compensation plans approved by Borrower’s board of directors, each as determined in accordance with GAAP; provided , however , the calculation of Consolidated Net Income for the periods ending September 30, 2008 and December 31, 2008 shall not include the 2008 Reserve.”

and substituting the following text therefore:

““ 2008 Reserve ”: is that certain pre-tax charge incurred in connection with the resolution of certain litigation involving the Lead Borrower, as more particularly described in EXHIBIT 6-17 hereof; provided , that solely for purposes of calculating EBITDA when determining (i) the Fixed Charge Coverage Ratio in Section 8-7 and (ii) the Leverage Ratio in Section 8-9, in each case for the quarterly periods listed below, such 2008 Reserve shall not exceed the following for the measurement periods indicated:

“ EBITDA ”: for any period, the Consolidated Net Income of the Lead Borrower and its Subsidiaries for such period adjusted by adding back thereto amounts deducted in computing such Consolidated Net Income in respect of each of (a) Consolidated Interest Expense, (b) provision for taxes in respect of income and profits of the Lead Borrower and its Subsidiaries, (c) depreciation and amortization of the Lead Borrower and its Subsidiaries, (d) other non-cash expenses incurred pursuant to employee equity compensation plans approved by Borrower’s board of directors, and (e) the applicable 2008 Reserve, if any, actually incurred, each as determined in accordance with GAAP.”

“(b)           The Borrowers do not have any contingent obligations or obligation under any Lease or Capital Lease which is not noted in the Borrowers’ financial statements furnished to the Lenders or has been otherwise disclosed in writing to the Lenders prior to the execution of this Agreement.”

and substituting the following text therefore:

“(b)           The Borrowers do not have any contingent obligations, other than the 2008 Reserve, or obligation under any Lease or Capital Lease which is not noted in the Borrowers’ financial statements furnished to the Lenders or has been otherwise disclosed in writing to the Lenders prior to the execution of this Agreement.”

“8-10 Net Profit .  The Borrowers shall earn a minimum Consolidated Net Income, as determined in accordance with GAAP, of at least $1.00, measured quarterly as of the end of each fiscal quarter of each fisca