Exhibit 10.1

VOTING AGREEMENT

        THIS VOTING AGREEMENT ("Voting Agreement") is entered into as of May 15, 2011, by and between KRATOS DEFENSE & SECURITY SOLUTIONS, INC., a Delaware corporation ("Parent"), and [    •    ] ("Stockholder").

RECITALS

        A.    Stockholder is a holder of record and the "beneficial owner" (within the meaning of Rule 13d-3 under the Securities Exchange Act of 1934, as amended (the "Exchange Act")) of certain shares of common stock of Integral Systems, Inc., a Maryland corporation (the "Company").

        B.    Parent, Iris Merger Sub Inc., a Maryland corporation ("Merger Sub"), Iris Acquisition Sub LLC, a Maryland LLC, and the Company are entering into an Agreement and Plan of Merger of even date herewith (the "Merger Agreement"), which provides (subject to the conditions set forth therein) for the merger of Merger Sub with and into the Company (the "Merger"). Capitalized terms used but not otherwise defined in this Voting Agreement have the meanings assigned to such terms in the Merger Agreement.

        C.    In the Merger, each outstanding share of common stock of the Company is to be converted into the right to receive the Merger Consideration.

        D.    Stockholder is entering into this Voting Agreement in order to induce Parent to enter into the Merger Agreement and cause the Merger to be consummated.

AGREEMENT

        The parties to this Voting Agreement, intending to be legally bound, agree as follows:

SECTION 1. CERTAIN DEFINITIONS

        For purposes of this Voting Agreement:

        (a)   "Expiration Date" shall mean the earlier of: (i) the date on which the Merger Agreement is terminated pursuant to Section 7.1 thereof; (ii) the date upon which the Merger becomes effective; or (iii) such date and time as any amendment or change to the Merger Agreement is effected without the Stockholder's consent that (A) decreases the Merger Consideration or (B) materially and adversely affects the Stockholder.

        (b)   Stockholder shall be deemed to "Own" or to have acquired "Ownership" of a security if Stockholder: (i) is the record owner of such security; or (ii) is the "beneficial owner" (within the meaning of Rule 13d-3 under the Exchange Act) of such security.

        (c)   "Subject Securities" shall mean: (i) all securities of the Company (including all Company Shares and all options, restricted stock units, warrants and other rights to acquire Company Shares) Owned by Stockholder as of the date of this Voting Agreement; and (ii) all additional securities of the Company (including all additional Company Shares and all additional options, restricted stock units, warrants and other rights to acquire Company Shares) of which Stockholder acquires Ownership during the Voting Period (whether such acquisition is a result of purchases or other transfers of Company Shares to Stockholder or by virtue of a stock dividend, stock split, recapitalization, reclassification, subdivision, combination or exchange of shares).

        (d)   A Person shall be deemed to have effected a "Transfer" of a security if such Person directly or indirectly: (i) sells, encumbers, grants an option with respect to, transfers or disposes of such security or any interest in such security to any Person other than Parent; (ii) enters into an agreement or commitment contemplating the possible sale of, encumbrance of, grant of an option with respect to, transfer of or disposition of such security or any interest therein to any Person

other than Parent; or (iii) reduces such Person's beneficial ownership of, interest in or risk relating to such security.

        (e)   "Voting Period" shall mean the period commencing on the date of this Voting Agreement and ending on the Expiration Date.

SECTION 2. TRANSFER OF SUBJECT SECURITIES AND VOTING RIGHTS

        2.1    Restriction on Transfer of Subject Securities.    Subject to Section 2.3, during the Voting Period, Stockholder shall not, directly or indirectly, cause or permit any Transfer of any of the Subject Securities to be effected; provided, however, that nothing contained in this Voting Agreement will be deemed to restrict the ability of Stockholder to exercise any Company Stock Options or the vesting of any Company Restricted Shares held by Stockholder prior to the Expiration Date.

        2.2    Restriction on Transfer of Voting Rights.    During the Voting Period, Stockholder shall ensure that: (a) none of the Subject Securities is deposited into a voting trust; and (b) no proxy is granted inconsistent with this Voting Agreement, and no voting agreement or similar agreement is entered into, with respect to any of the Subject Securities.

        2.3    Permitted Transfers.    Section 2.1 shall not prohibit a Transfer of Subject Securities by Stockholder: (a) if Stockholder is an individual: (i) to any member of Stockholder's immediate family; or to a trust for the benefit of Stockholder or any member of Stockholder's immediate family; or (ii) upon the death of Stockholder; or (b) if Stockholder is a partnership or limited liability company, to one or more partners or members of Stockholder or to an affiliated corporation under common control with Stockholder; provided, however, that a Transfer referred to in this Section 2.3 shall be permitted only if, as a precondition to such Transfer, the transferee agrees in a writing, reasonably satisfactory in form and substance to Parent, to be bound by all of the terms of this Voting Agreement.

SECTION 3. VOTING OF SHARES

        3.1    Voting Covenant.    Stockholder hereby agrees that, prior to the Expiration Date, at any meeting of the stockholders of the Company, however called, or at any adjournment or postponement thereof, and on every action or approval by written consent of the stockholders of the Company, unless otherwise directed in writing by Parent, Stockholder shall appear at the meeting or otherwise cause any and all issued and outstanding Company Shares Owned by Stockholder as of the applicable record date to be counted as present thereat for purposes of establishing a quorum and vote (or cause to be voted) any and all such Company Shares:

        (a)   in favor of the adoption of the Merger Agreement and the Merger;

        (b)   against any Company Alternative Proposal; and

        (c)   against any other action, agreement, proposal or transaction involving the Company or any of its subsidiaries which other action, agreement, proposal or transaction would compete with, interfere with, impede, frustrate, prevent, burden or nullify the Merger or the Merger Agreement.

Prior to the Expiration Date, Stockholder shall not enter into any agreement or understanding with any Person to vote or give instructions in any manner inconsistent with clause "(a)," clause "(b)" or clause "(c)" of the preceding sentence.

        3.2    Proxy.    

        (a)   Contemporaneously with the execution of this Voting Agreement: (i) Stockholder shall deliver to Parent a proxy in the form attached to this Voting Agreement as Exhibit A, which shall be irrevocable to the fullest extent permitted by law (at all times during the Voting Period) with respect to the shares referred to therein (the "Proxy"); and (ii) if applicable, Stockholder shall cause to be delivered to Parent an additional proxy (in the form attached hereto as Exhibit A) executed on behalf of the record owner of any outstanding Company Shares that are owned

beneficially (within the meaning of Rule 13d-3 under the Exchange Act), but not of record by Stockholder.

        (b)   Stockholder shall not enter into any tender, voting or other agreement, or grant a proxy or power of attorney, with respect to the Subject Securities that is inconsistent with this Voting Agreement or otherwise take any other action with respect to the Subject Securities that would in any way restrict, limit or interfere with the performance of Stockholder's obligations hereunder or the transactions contemplated hereby.

SECTION 4. ADDITIONAL COVENANTS OF STOCKHOLDER

        4.1    No Solicitation.    Stockholder agrees that, during the Voting Period, Stockholder shall not (without limiting any of the other restrictions in this Voting Agreement), directly or indirectly, take or authorize to be taken any action that the Company is prohibited from taking or authorizing to be taken pursuant to Section 5.7 of the Merger Agreement

        4.2    Notice of Certain Events.    Stockholder agrees to promptly notify Parent of any development occurring after the date hereof that causes any breach of any of the representations and warranties of Stockholder set forth in Section 5 herein.

SECTION 5. REPRESENTATIONS AND WARRANTIES OF STOCKHOLDER

        Stockholder hereby represents and warrants to Parent as follows:

        5.1    Authorization, etc.    Stockholder has the power, authority and capacity to execute and deliver this Voting Agreement and the Proxy and to perform Stockholder's obligations hereunder and thereunder. This Voting Agreement and the Proxy have been duly executed and delivered by Stockholder and, assuming the due authorization, execution and delivery of this Voting Agreement by Parent, constitute legal, valid and binding obligations of Stockholder, enforceable against Stockholder in accordance with their terms, subject to: (a) laws of general application relating to bankruptcy, insolvency and the relief of debtors; and (b) rules of law governing specific performance, injunctive relief and other equitable remedies.

        5.2    No Conflicts or Consents.    

        (a)   The execution and delivery of this Voting Agreement and the Proxy by Stockholder do not, and the performance of this Voting Agreement and the Proxy by Stockholder will not: (i) conflict with or violate any Law applicable to Stockholder or by which Stockholder or any of Stockholder's properties is or may be bound or affected; or (ii) result in or constitute (with or without notice or lapse of time) any breach of or default under, or give to any other Person (with or without notice or lapse of time) any right of termination, amendment, acceleration or cancellation of, or result (with or without notice or lapse of time) in the creation of any liens or other encumbrances on any of the Subject Securities.

        (b)   The execution and delivery of this Voting Agreement and the Proxy by Stockholder do not, and the performance of this Voting Agreement and the Proxy by Stockholder will not, require any consent or approval of any Person.

        5.3    Title to Securities.    As of the date of this Voting Agreement: (a) Stockholder holds of record (free and clear of any liens or other encumbrances) the number of outstanding Company Shares set forth under the heading "Shares Held of Record" on the signature page hereof; (b) Stockholder holds (free and clear of any liens or other encumbrances) the options, restricted stock units, warrants and other rights to acquire Company Shares set forth under the heading "Options and Other Rights" on the signature page hereof; (c) Stockholder Owns the additional securities of the Company set forth under the heading "Additional Securities Beneficially Owned" on the signature page hereof; and (d) Stockholder does not directly or indirectly Own any shares of capital stock or other securities of the Company, or any option, restricted stock unit, warrant or other right to acquire (by purchase, conversion or otherwise) any shares of capital stock or other securities of the Company, other than the

shares and options, restricted stock units, warrants and other rights set forth on the signature page hereof.

        5.4    Power.    Unless otherwise indicated on the signature pages hereto, Stockholder, together with its affiliates, has sole voting power and sole power to issue instructions with respect to the matters set forth in Sections 2 and 3 hereof and sole power to agree to all of the matters set forth in this Agreement, in each case with respect to all of the Subject Securities, with no limitations, qualifications or restrictions on such rights.

        5.5    Accuracy of Representations.    The representations and warranties contained in this Voting Agreement are accurate in all respects as of the date of this Voting Agreement, and will be accurate in all respects at all times prior to the Expiration Date as if made as of any such time or date.

SECTION 6. MISCELLANEOUS

        6.1    Stockholder Information.    Stockholder hereby agrees to permit Parent, the Company and Merger Sub to publish and disclose in the Form S-4 Registration Statement, the Joint Proxy Statement/Prospectus and any other public disclosure that Parent and the Company mutually determine to be necessary or desirable in connection with the Merger and any other transactions contemplated by the Merger Agreement, Stockholder's identity and ownership of Company Shares and the nature of Stockholder's commitments, arrangements and understandings under this Voting Agreement.

        6.2    Further Assurances.    From time to time and without additional consideration, Stockholder shall execute and deliver, or cause to be executed and delivered, such additional transfers, assignments, endorsements, proxies, consents and other instruments, and shall take such further actions, as Parent may reasonably request for the purpose of carrying out and furthering the intent of this Voting Agreement.

        6.3    Expenses.    All costs and expenses incurred in connection with the transactions contemplated by this Voting Agreement shall be paid by the party incurring such costs and expenses.

        6.4    Notices.    All notices, requests, claims, demands and other communications hereunder shall be in writing and shall be given (and shall be deemed to have been duly given upon receipt) by delivery in person, by facsimile or by registered or certified mail (postage prepaid, return receipt requested) to the respective parties at the following addresses (or at such other address for a party as shall be specified by like notice):

if to Stockholder:

at the address set forth on the signature page hereof; and

if to Parent:

Kratos Defense & Security Solutions, Inc.
4820 Eastgate Mall
San Diego, CA 92121
Attention: General Counsel
Facsimile: (858) 812-7303

with an additional copy (which shall not constitute notice) to:

Paul, Hastings, Janofsky & Walker LLP
4747 Executive Drive, 12th Floor
San Diego, California 92121
Attention:  Deyan P. Spiridonov
                    Teri E. O'Brien, Esq.
Facsimile: 858-458-3005

        6.5    Severability.    If any term or other provision of this Voting Agreement is invalid, illegal or incapable of being enforced by any rule of law or public policy, all other conditions and provisions of

this Voting Agreement shall nevertheless remain in full force and effect so long as the economic or legal substance of the transactions contemplated hereby is not affected in any manner adverse to any party. Upon such determination that any term or other provision is invalid, illegal or incapable of being enforced, the parties hereto shall negotiate in good faith to modify this Voting Agreement so as to effect the original intent of the parties as closely as possible in an acceptable manner to the end that the transactions contemplated hereby are fulfilled to the fullest extent possible.

        6.6    Entire Agreement.    This Voting Agreement, the Proxy, the Merger Agreement and any other documents delivered by the parties in connection herewith constitute the entire agreement between the parties with respect to the subject matter hereof and thereof and supersede all prior agreements and understandings between the parties with respect thereto.

        6.7    Amendments.    This Voting Agreement may not be amended, modified, altered or supplemented other than by means of a written instrument duly executed and delivered on behalf of Parent and Stockholder.

        6.8    Assignment; Binding Effect; No Third Party Rights.    Except as provided herein, neither this Voting Agreement nor any of the interests or obligations hereunder may be assigned or delegated by Stockholder, and any attempted or purported assignment or delegation of any of such interests or obligations shall be void. Subject to the preceding sentence, this Voting Agreement shall be binding upon Stockholder and Stockholder's heirs, estate, executors and personal representatives and Stockholder's successors and assigns, and shall inure to the benefit of Parent and its successors and assigns. Without limiting any of the restrictions set forth in Section 2, Section 3 or elsewhere in this Voting Agreement, this Voting Agreement shall be binding upon any Person to whom any Subject Securities are transferred. Nothing in this Voting Agreement is intended to confer on any Person (other than Parent and its successors and assigns) any rights or remedies of any nature.

        6.9    Specific Performance.    The parties agree that irreparable damage would occur in the event that any of the provisions of this Voting Agreement or the Proxy were not performed in accordance with its specific terms or were otherwise breached. Stockholder agrees that, in the event of any breach or threatened breach by Stockholder of any covenant or obligation contained in this Voting Agreement or in the Proxy, Parent shall be entitled (in addition to any other remedy that may be available to it, including monetary damages) to obtain: (a) a decree or order of specific performance to enforce the observance and performance of such covenant or obligation; and (b) an injunction restraining such breach or threatened breach. Stockholder further agrees that neither Parent nor any other Person shall be required to obtain, furnish or post any bond or similar instrument in connection with or as a condition to obtaining any remedy referred to in this Section 6.9, and Stockholder irrevocably waives any right he or it may have to require the obtaining, furnishing or posting of any such bond or similar instrument.

        6.10    Attorneys' Fees.    If any proceeding relating to this Voting Agreement or the enforcement of any provision of this Voting Agreement is brought against Stockholder, the prevailing party shall be entitled to recover reasonable attorneys' fees, costs and disbursements (in addition to any other relief to which the prevailing party may be entitled).

        6.11    Non-Exclusivity.    The rights and remedies of Parent under this Voting Agreement are not exclusive of or limited by any other rights or remedies which it may have, whether at law, in equity, by contract or otherwise, all of which shall be cumulative (and not alternative).

        6.12    Governing Law.    This Agreement shall be governed by, and construed in accordance with, the laws of the State of Maryland (without giving effect to choice of law principles thereof).

        6.13    Counterparts; Exchanges by Facsimile or Electronic Delivery.    This Voting Agreement may be executed in separate counterparts, each of which when so executed and delivered shall be an original, but all such counterparts shall together constitute one and the same instrument. The exchange of a fully executed Voting Agreement (in counterparts or otherwise) by facsimile or electronic delivery shall be sufficient to bind the parties to the terms and conditions of this Voting Agreement.

        6.14    Headings.    The descriptive headings contained in this Voting Agreement are included for convenience of reference only and shall not affect in any way the meaning or interpretation of this Voting Agreement.

        6.15    Waiver.    Subject to the remainder of this Section 6.15, at any time prior to the Expiration Date, any party hereto may: (a) extend the time for the performance of any of the obligations or other acts of the other parties to this Voting Agreement; (b) waive any inaccuracy in or breach of any representation, warranty, covenant or obligation of the other party in this Voting Agreement or in any document delivered pursuant to this Voting Agreement; and (c) waive compliance with any covenant, obligation or condition for the benefit of such party contained in this Voting Agreement. No failure on the part of Parent to exercise any power, right, privilege or remedy under this Voting Agreement, and no delay on the part of Parent in exercising any power, right, privilege or remedy under this Voting Agreement, shall operate as a waiver of such power, right, privilege or remedy; and no single or partial exercise of any such power, right, privilege or remedy shall preclude any other or further exercise thereof or of any other power, right, privilege or remedy. Parent shall not be deemed to have waived any claim available to Parent arising out of this Voting Agreement, or any power, right, privilege or remedy of Parent under this Voting Agreement, unless the waiver of such claim, power, right, privilege or remedy is expressly set forth in a written instrument duly executed and delivered on behalf of Parent; and any such waiver shall not be applicable or have any effect except in the specific instance in which it is given.

        6.16    Independence of Obligations.    The covenants and obligations of Stockholder set forth in this Voting Agreement shall be construed as independent of any other contract between Stockholder, on the one hand, and the Company or Parent, on the other. The existence of any claim or cause of action by Stockholder against the Company or Parent shall not constitute a defense to the enforcement of any of such covenants or obligations against Stockholder. Nothing in this Voting Agreement shall limit any of the rights or remedies of Parent under the Merger Agreement, or any of the rights or remedies of Parent or any of the obligations of Stockholder under any agreement between Stockholder and Parent or any certificate or instrument executed by Stockholder in favor of Parent; and nothing in the Merger Agreement or in any other such agreement, certificate or instrument, shall limit any of the rights or remedies of Parent or any of the obligations of Stockholder under this Voting Agreement.

        6.17    Other Capacities.    Notwithstanding any provision of this Voting Agreement to the contrary, nothing in this Voting Agreement shall limit or restrict Stockholder from acting in good faith in Stockholder's capacity as a director or officer of the Company (it being understood that this Voting Agreement shall apply to Stockholder solely in Stockholder's capacity as a stockholder of the Company).

        6.18    Construction.    

        (a)   For purposes of this Voting Agreement, whenever the context requires: the singular number shall include the plural, and vice versa; the masculine gender shall include the feminine and neuter genders; the feminine gender shall include the masculine and neuter genders; and the neuter gender shall include masculine and feminine genders.

        (b)   The parties agree that any rule of construction to the effect that ambiguities are to be resolved against the drafting party shall not be applied in the construction or interpretation of this Voting Agreement.

        (c)   As used in this Voting Agreement, the words "include" and "including," and variations thereof, shall not be deemed to be terms of limitation, but rather shall be deemed to be followed by the words "without limitation."

        (d)   Except as otherwise indicated, all references in this Voting Agreement to "Sections" and "Exhibits" are intended to refer to Sections of this Voting Agreement and Exhibits to this Voting Agreement.

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        IN WITNESS WHEREOF, Parent and Stockholder have caused this Voting Agreement to be executed as of the date first written above.

EXHIBIT A

FORM OF IRREVOCABLE PROXY

Proxy

IRREVOCABLE PROXY

        The undersigned stockholder (the "Stockholder") of Integral Systems, Inc., a Maryland corporation (the "Company"), hereby irrevocably (to the fullest extent permitted by law) appoints and constitutes Kratos Defense & Security Solutions, Inc., a Delaware corporation ("Parent"), and Eric DeMarco and Deanna Lund, solely in their capacities as executive officers of Parent, and each of them, the attorneys and proxies of the Stockholder, with full power of substitution and resubstitution, to the full extent of the Stockholder's rights with respect to the outstanding shares of capital stock of the Company owned of record by the Stockholder as of the date of this proxy, which shares are specified on the final page of this proxy, and any and all other shares or securities issued or issuable in respect thereof on or after the date hereof and prior to the date this proxy terminates. (The shares of the capital stock of the Company and other securities referred to in the immediately preceding sentence are referred to as the "Shares.") Upon the execution of this proxy, all prior proxies given by the Stockholder with respect to any of the Shares are hereby revoked, and the Stockholder agrees that no subsequent proxies inconsistent with this Proxy will be given with respect to any of the Shares.

        This proxy is irrevocable, is coupled with an interest and is granted in connection with, and as security for, the Voting Agreement, dated as of the date hereof, between Parent and the Stockholder (the "Voting Agreement"), and is granted in consideration of Parent entering into the Agreement and Plan of Merger, dated as of the date hereof, among Parent, Iris Merger Sub Inc., a wholly-owned subsidiary of Parent, Iris Acquisition Sub LLC, a wholly-owned subsidiary of Parent, and the Company (the "Merger Agreement"). This proxy will terminate on the Expiration Date (as defined in the Voting Agreement). Capitalized terms used but not otherwise defined in this Irrevocable Proxy have the meanings assigned to such terms in the Merger Agreement.

        Prior to the Expiration Date, the attorneys and proxies named above will be empowered, and may exercise this proxy, to vote any Shares owned by the undersigned, at any meeting of the stockholders of the Company, however called, or at any adjournment or postponement thereof and on every action or approval by written consent of the stockholders of the Company:

        (a)   in favor of the approval of the Merger Agreement and the Merger;

        (b)   against any Company Alternative Proposal; and

        (c)   against any other action, agreement, proposal or transaction involving the Company or any of its subsidiaries which other action, agreement, proposal or transaction would compete with, interfere with, impede, frustrate, prevent, burden or nullify the Merger or the Merger Agreement.

        The Stockholder may vote the Shares on all other matters not referred to in this proxy, and the attorneys and proxies named above may not exercise this proxy with respect to such other matters.

        This proxy shall be binding upon the heirs, estate, executors, personal representatives, successors and assigns of the Stockholder (including any transferee of any of the Shares).

        Any term or provision of this proxy that is invalid or unenforceable in any situation in any jurisdiction shall not affect the validity or enforceability of the remaining terms and provisions of this proxy or the validity or enforceability of the offending term or provision in any other situation or in any other jurisdiction. Upon such determination that any term or provision is invalid, illegal or incapable of being enforced, the parties hereto shall negotiate in good faith to modify this proxy so as to effect the original intent of the parties as closely as possible in an acceptable manner to the end that the transactions contemplated hereby are fulfilled to the fullest extent possible.

[Signature page follows]

Proxy

Proxy

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Exhibit 10.1