5,770,000 Shares SOURCEFIRE, INC. COMMON STOCK (PAR VALUE $0.001 PER SHARE) UNDERWRITING AGREEMENT

Exhibit 1.1

5,770,000 Shares

SOURCEFIRE, INC.

COMMON STOCK (PAR VALUE $0.001 PER SHARE)

UNDERWRITING AGREEMENT

                                        , 2007

                                        , 2007

▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. Incorporated
▇▇▇▇▇▇ Brothers Inc.
UBS Securities LLC
▇▇▇▇▇▇▇▇▇ & Company, Inc.
c/o Morgan ▇▇▇▇▇▇▇ & Co. Incorporated
▇▇▇▇ ▇▇▇▇▇▇▇▇
▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇

Ladies and Gentlemen:

     Sourcefire, Inc., a Delaware corporation (the “Company”), proposes to issue and sell to the several Underwriters named in Schedule II hereto (the “Underwriters”), and certain shareholders of the Company (the “Selling Shareholders”) named in Schedule I hereto severally propose to sell to the several Underwriters, an aggregate of 5,770,000 shares of Common Stock (par value $0.001 per share) of the Company (the “Firm Shares”), of which 5,320,000 shares are to be issued and sold by the Company and 450,000 shares are to be sold by the Selling Shareholders, each Selling Shareholder selling the amount set forth opposite such Selling Shareholder’s name in Schedule I hereto.

     The Company also proposes to issue and sell to the several Underwriters not more than an additional 865,000 shares of Common Stock (par value $0.001 per share) of the Company (the “Additional Shares”) if and to the extent that you, as managers of the offering, shall have determined to exercise, on behalf of the Underwriters, the right to purchase such shares of common stock granted to the Underwriters in Section 3 hereof. The Firm Shares and the Additional Shares are hereinafter collectively referred to as the “Shares.” The shares of Common Stock (par value $0.001 per share) of the Company to be outstanding after giving effect to the sales contemplated hereby are hereinafter referred to as the “Common Stock.” The Company and the Selling Shareholders are hereinafter sometimes collectively referred to as the “Sellers.”

     The Company has filed with the Securities and Exchange Commission (the “Commission”) a registration statement, including a prospectus, relating to the Shares. The registration statement as amended at the time it becomes effective, including the information (if any) deemed to be part of the registration statement at the time of effectiveness pursuant to Rule 430A under the Securities Act of 1933, as amended (the “Securities Act”), is hereinafter referred to as the “Registration Statement”; the prospectus in the form first used to confirm sales of Shares (or in the form first made available to the Underwriters by the Company to meet requests of purchasers pursuant to Rule 173 under the Securities Act) is hereinafter referred to as the “Prospectus.” If the Company has filed an

abbreviated registration statement to register additional shares of Common Stock pursuant to Rule 462(b) under the Securities Act (the “Rule 462 Registration Statement”), then any reference herein to the term “Registration Statement” shall be deemed to include such Rule 462 Registration Statement.

     For purposes of this Agreement, “free writing prospectus” has the meaning set forth in Rule 405 under the Securities Act, “Time of Sale Prospectus” means the preliminary prospectus together with the free writing prospectuses, if any, each identified in Schedule III hereto, and “broadly available road show” means a “bona fide electronic road show” as defined in Rule 433(h)(5) under the Securities Act that has been made available without restriction to any person. As used herein, the terms “Registration Statement,” “preliminary prospectus,” “Time of Sale Prospectus” and “Prospectus” shall include the documents, if any, incorporated by reference therein.

     1. Representations and Warranties of the Company. The Company represents and warrants to and agrees with each of the Underwriters that:

     (a) The Registration Statement has become effective; no stop order suspending the effectiveness of the Registration Statement is in effect, and no proceedings for such purpose are pending before or, to the Company’s knowledge, threatened by the Commission.

     (b) (i) The Registration Statement, when it became effective, did not contain and, as amended or supplemented, if applicable, will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading, (ii) the Registration Statement and the Prospectus comply and, as amended or supplemented, if applicable, will comply in all material respects with the Securities Act and the applicable rules and regulations of the Commission thereunder, (iii) the Time of Sale Prospectus does not, and at the time of each sale of the Shares in connection with the offering when the Prospectus is not yet available to prospective purchasers and at the Closing Date (as defined in Section 5), the Time of Sale Prospectus, as then amended or supplemented by the Company, if applicable, will not, contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, (iv) each broadly available road show, if any, when considered together with the Time of Sale Prospectus, does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading and (v) the Prospectus does not contain and, as amended or supplemented, if applicable, will not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, except that the representations and warranties set forth in this paragraph do not apply to statements or omissions in the Registration Statement, the Time of Sale Prospectus, each broadly available

roadshow or the Prospectus based upon information relating to any Underwriter furnished to the Company in writing by such Underwriter through you expressly for use therein.

     (c) The Company is not an “ineligible issuer” in connection with the offering pursuant to Rules 164, 405 and 433 under the Securities Act. Any free writing prospectus that the Company is required to file pursuant to Rule 433(d) under the Securities Act has been, or will be, filed with the Commission in accordance with the requirements of the Securities Act and the applicable rules and regulations of the Commission thereunder. Each free writing prospectus that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act or that was prepared by or on behalf of or used or referred to by the Company complies or will comply in all material respects with the requirements of the Securities Act and the applicable rules and regulations of the Commission thereunder. Except for the free writing prospectuses, if any, identified in Schedule III hereto, and electronic road shows, if any, furnished to you before first use, the Company has not prepared, used or referred to, and will not, without your prior consent, prepare, use or refer to, any free writing prospectus.

     (d) The Company has been duly incorporated, is validly existing as a corporation in good standing under the laws of the jurisdiction of its incorporation, has the corporate power and authority to own its property and to conduct its business as described in the Time of Sale Prospectus and is duly qualified to transact business and is in good standing in each jurisdiction in which the conduct of its business or its ownership or leasing of property requires such qualification, except to the extent that the failure to be so qualified or be in good standing would not have a material adverse effect on the Company and its subsidiaries, taken as a whole.

     (e) Each subsidiary of the Company has been duly incorporated, is validly existing as a corporation in good standing under the laws of the jurisdiction of its incorporation, has the corporate power and authority to own its property and to conduct its business as described in the Time of Sale Prospectus and is duly qualified to transact business and is in good standing in each jurisdiction in which the conduct of its business or its ownership or leasing of property requires such qualification, except to the extent that the failure to be so qualified or be in good standing would not have a material adverse effect on the Company and its subsidiaries, taken as a whole; all of the issued shares of capital stock of each subsidiary of the Company have been duly and validly authorized and issued, are fully paid and non-assessable and are owned directly by the Company, free and clear of all liens, encumbrances, equities or claims.

     (f) This Agreement has been duly authorized, executed and delivered by the Company.

     (g) The authorized capital stock of the Company conforms as to legal matters in all material respects to the description thereof contained under the

heading “Description of Capital Stock” in each of the Time of Sale Prospectus and the Prospectus.

     (h) The shares of Common Stock (including the Shares to be sold by the Selling Shareholders) outstanding prior to the issuance of the Shares to be sold by the Company have been duly authorized and are validly issued, fully paid and non-assessable.

     (i) The Shares to be sold by the Company have been duly authorized and, when issued and delivered in accordance with the terms of this Agreement, will be validly issued, fully paid and non-assessable, and the issuance of such Shares will not be subject to any preemptive or similar rights.

     (j) The execution and delivery by the Company of, and the performance by the Company of its obligations under, this Agreement will not contravene (i) any provision of applicable law or (ii) the certificate of incorporation or by-laws of the Company or (iii) any agreement or other instrument binding upon the Company or any of its subsidiaries that is material to the Company and its subsidiaries, taken as a whole, or (iv) any judgment, order or decree of any governmental body, agency or court having jurisdiction over the Company or any subsidiary, except, in the case of clauses (iii) and (iv), for any such contravention that would not have a material adverse effect on the Company and its subsidiaries, taken as a whole, and no consent, approval, authorization or order of, or qualification with, any governmental body or agency is required for the performance by the Company of its obligations under this Agreement, except (i) for the registration of the Shares under the Securities Act, (ii) for such registration as is required under the Securities Exchange Act of 1934, as amended (the “Exchange Act”) and (iii) such as may be required by the securities or Blue Sky laws of the various states in connection with the offer and sale of the Shares.

     (k) There has not occurred any material adverse change, or any development involving a prospective material adverse change, in the condition, financial or otherwise, or in the earnings, business or operations of the Company and its subsidiaries, taken as a whole, from that set forth in the Time of Sale Prospectus.

     (l) There are no legal or governmental proceedings pending or, to the Company’s knowledge, threatened to which the Company or any of its subsidiaries is a party or to which any of the properties of the Company or any of its subsidiaries is subject (i) other than (A) proceedings accurately described in all material respects in the Time of Sale Prospectus or (B) proceedings that would not have a material adverse effect on the Company and its subsidiaries, taken as a whole, or on the power or ability of the Company to perform its obligations under this Agreement or to consummate the transactions contemplated by the Time of Sale Prospectus or (ii) that are required to be described in the Registration Statement or the Prospectus and are not so described; and there are no statutes or regulations to which the Company or any of its subsidiaries is subject, or any

contracts or other documents to which the Company or any of its subsidiaries is a party that are required to be described in the Registration Statement or the Prospectus or to be filed as exhibits to the Registration Statement that are not described or filed as required.

     (m) Each preliminary prospectus filed as part of the registration statement as originally filed or as part of any amendment thereto, or filed pursuant to Rule 424 under the Securities Act, complied when so filed in all material respects with the Securities Act and the applicable rules and regulations of the Commission thereunder.

     (n) The Company is not, and after giving effect to the offering and sale of the Shares and the application of the proceeds thereof as described in the Prospectus under the heading “Use of Proceeds” will not be, required to register as an “investment company” as such term is defined in the Investment Company Act of 1940, as amended.

     (o) The Company and its subsidiaries (i) are in compliance with any and all applicable foreign, federal, state and local laws and regulations relating to the protection of human health and safety, the environment or hazardous or toxic substances or wastes, pollutants or contaminants (“Environmental Laws”), (ii) have received all permits, licenses or other approvals required of them under applicable Environmental Laws to conduct their respective businesses and (iii) are in compliance with all terms and conditions of any such permit, license or approval, except where such noncompliance with Environmental Laws, failure to receive required permits, licenses or other approvals or failure to comply with the terms and conditions of such permits, licenses or approvals would not, singly or in the aggregate, have a material adverse effect on the Company and its subsidiaries, taken as a whole.

     (p) To the Company’s knowledge, there are no costs or liabilities associated with Environmental Laws (including, without limitation, any capital or operating expenditures required for clean-up, closure of properties or compliance with Environmental Laws or any permit, license or approval, any related constraints on operating activities and any potential liabilities to third parties) which would, singly or in the aggregate, have a material adverse effect on the Company and its subsidiaries, taken as a whole.

     (q) There are no contracts, agreements or understandings between the Company and any person granting such person the right to require the Company to file a registration statement under the Securities Act with respect to any securities of the Company or to require the Company to include such securities with the Shares registered pursuant to the Registration Statement, except such rights that have been duly waived in writing by such person.

     (r) Subsequent to the respective dates as of which information is given in each of the Registration Statement, the Time of Sale Prospectus and the

Prospectus, (i) the Company and its subsidiaries, taken as a whole, have not incurred any material liability or obligation, direct or contingent, nor entered into any material transaction outside the ordinary course of business; (ii) the Company has not purchased any of its outstanding capital stock, nor declared, paid or otherwise made any dividend or distribution of any kind on its capital stock other than ordinary and customary dividends; and (iii) there has not been any material change in the capital stock, short-term debt or long-term debt of the Company and its subsidiaries, except in each case as otherwise described in each of the Registration Statement, the Time of Sale Prospectus and the Prospectus, respectively.

     (s) The Company and its subsidiaries have good and marketable title in fee simple to all real property and good and marketable title to all personal property owned by them which is material to the business of the Company and its subsidiaries, taken as a whole, in each case free and clear of all liens, encumbrances and defects except such as are described in the Time of Sale Prospectus or such as do not materially affect the value of such property and do not materially interfere with the use made and proposed to be made of such property by the Company and its subsidiaries; and any real property and buildings held under lease by the Company and its subsidiaries are held by them under valid, subsisting and enforceable leases with such exceptions as are not material and do not materially interfere with the use made and proposed to be made of such property and buildings by the Company and its subsidiaries, in each case except as described in the Time of Sale Prospectus.

     (t) The Company and its subsidiaries own or possess or have the right to use, or can acquire on reasonable terms ownership or the right to use, all material patents, patent rights, licenses, inventions, copyrights, know-how (including trade secrets and other unpatented and/or unpatentable proprietary or confidential information, systems or procedures), trademarks, service marks and trade names (collectively, the “Intellectual Property”) currently employed by them in connection with the business now operated by them, and, except as described in the Time of Sale Prospectus, neither the Company nor any of its subsidiaries has received any written notice of infringement of or conflict with asserted rights of others with respect to any of the foregoing which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would have a material adverse effect on the Company and its subsidiaries, taken as a whole.

     (u) No material labor dispute with the employees of the Company or any of its subsidiaries exists, except as described in the Time of Sale Prospectus, or, to the knowledge of the Company, is imminent; and none of the executive officers of the Company is aware of any existing, threatened or imminent labor disturbance by the employees of any of its principal suppliers, manufacturers or contractors that could reasonably be expected to have a material adverse effect on the Company and its subsidiaries, taken as a whole.

     (v) The Company and each of its subsidiaries are insured by insurers of recognized financial responsibility against such losses and risks and in such amounts as are customary in the businesses in which they are engaged; neither the Company nor any of its subsidiaries has been refused any insurance coverage sought or applied for in the past 12 months; and neither the Company nor any of its subsidiaries has any reason to believe that it will not be able to renew its existing insurance coverage as and when such coverage expires or to obtain similar coverage from similar insurers as may be necessary to continue its business at a cost that would not have a material adverse effect on the Company and its subsidiaries, taken as a whole, except as described in the Time of Sale Prospectus.

     (w) The Company and its subsidiaries possess all certificates, authorizations and permits issued by the appropriate federal, state or foreign regulatory authorities necessary to conduct their respective businesses as described in the Time of Sale Prospectus, except where any failures to possess the same would not reasonably be expected to have a material adverse effect on the Company and its subsidiaries, taken as a whole, and neither the Company nor any of its subsidiaries has received any written notice of proceedings relating to the revocation or modification of any such certificate, authorization or permit which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would have a material adverse effect on the Company and its subsidiaries, taken as a whole, except as described in the Time of Sale Prospectus.

     (x) The Company and its subsidiaries maintain a system of internal accounting controls sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management’s general or specific authorizations; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting principles and to maintain asset accountability; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; and (iv) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences. Except as described in the Time of Sale Prospectus, since the end of the Company’s most recent audited fiscal year, there has been (i) no material weakness in the Company’s internal control over financial reporting (whether or not remediated) and (ii) no change in the Company’s internal control over financial reporting that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting.

     (y) Except as described in the Time of Sale Prospectus, the Company has not sold, issued or distributed any shares of Common Stock during the six-month period preceding the date hereof, including any sales pursuant to Rule 144A under, or Regulation D or S of, the Securities Act, other than shares issued pursuant to employee benefit plans, qualified stock option plans or other employee compensation plans or pursuant to outstanding options, rights or warrants.

     2. Representations and Warranties of the Selling Shareholders. Each Selling Shareholder, severally and not jointly, represents and warrants to and agrees with each of the Underwriters that:

     (a) This Agreement has been duly authorized, executed and delivered by or on behalf of such Selling Shareholder.

     (b) The execution and delivery by such Selling Shareholder of, and the performance by such Selling Shareholder of its obligations under, this Agreement, the Custody Agreement signed by such Selling Shareholder and                     , as Custodian, relating to the deposit of the Shares to be sold by such Selling Shareholder (the “Custody Agreement”) and the Power of Attorney appointing certain individuals as such Selling Shareholder’s attorneys-in-fact to the extent set forth therein, relating to the transactions contemplated hereby and by the Registration Statement (the “Power of Attorney”) will not contravene any provision of (i) applicable law, or (ii) the certificate of incorporation or by-laws of such Selling Shareholder (if such Selling Shareholder is a corporation), or (iii) any agreement or other instrument binding upon such Selling Shareholder or any judgment, order or decree of any governmental body, agency or court having jurisdiction over such Selling Shareholder, except, in the case of clauses (i) and (iii) above, where such contravention will not impair in any material respect the consummation of such Selling Shareholder’s obligations under this Agreement or the Custody Agreement or Power of Attorney, and (iv) no consent, approval, authorization or order of, or qualification with, any governmental body or agency is required for the performance by such Selling Shareholder of its obligations under this Agreement or the Custody Agreement or Power of Attorney of such Selling Shareholder, except such as may have previously been made or obtained or as may be required (i) under the Securities Act or regulations promulgated thereunder; (ii) by the securities or Blue Sky laws of the various states in connection with the offer and sale of the Shares; (iii) pursuant to the rules and regulations of the NASD; and (iv) under the laws and regulations of jurisdictions outside the United States in which any Shares are offered.

     (c) Such Selling Shareholder has, and on the Closing Date will have, valid title to, or a valid “security entitlement” within the meaning of Section 8-501 of the New York Uniform Commercial Code in respect of, the Shares to be sold by such Selling Shareholder free and clear of all security interests, claims, liens, equities or other encumbrances and the legal right and power, and all authorization and approval required by law, to enter into this Agreement, the Custody Agreement and the Power of Attorney and to sell, transfer and deliver the Shares to be sold by such Selling Shareholder or a security entitlement in respect of such Shares.

     (d) The Custody Agreement and the Power of Attorney have been duly authorized, executed and delivered by such Selling Shareholder and are valid and binding agreements of such Selling Shareholder except (a) as rights to indemnification and contribution are limited by applicable law; (b) as limited by

applicable bankruptcy and other laws affecting creditor’s rights; and (c) as limited by laws relating to the availability of specific performance injunctive relief or other equitable remedies.

     (e) Upon indication by book entry that the Shares to be sold by such Selling Shareholder pursuant to this Agreement have been credited to a securities account maintained by the Underwriters at the Depository Trust Company (“DTC”) and payment therefor in accordance with this Agreement (assuming that neither DTC nor any such Underwriter has notice of any adverse claim (within the meaning of Section 8-105 of the New York Uniform Commercial Code (the “UCC”)) to such Shares), (A) under Section 8-501 of the UCC, the Underwriters will acquire a valid security entitlement with respect to such Shares and (C) no action based on any “adverse claim”, within the meaning of Section 8-102 of the UCC, to such Shares may be asserted against any Underwriter with respect to such security entitlement; for purposes of this representation, such Selling Shareholder may assume that DTC is a securities intermediary as defined in Section 8-1-2(14) of the UCC.

     (f) (i) The Registration Statement, when it became effective, did not contain and, as amended or supplemented, if applicable, will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading, (ii) the Time of Sale Prospectus does not, and at the time of each sale of the Shares in connection with the offering when the Prospectus is not yet available to prospective purchasers and at the Closing Date (as defined in Section 5), the Time of Sale Prospectus, as then amended or supplemented by the Company, if applicable, will not, contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, (iii) each broadly available road show, if any, when considered together with the Time of Sale Prospectus, does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading and (iv) the Prospectus does not contain and, as amended or supplemented, if applicable, will not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, except that the representations and warranties set forth in this paragraph 2(f) apply only to statements or omissions made in reliance upon and in conformity with information relating to such Selling Shareholder furnished in writing by or on behalf of such Selling Shareholder expressly for use in the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, any issuer free writing prospectus as defined in Rule 433(h) under the Securities Act, or the Prospectus or any amendment or supplement thereto (the “Provided Information”).

     (g) Such Selling Shareholder is not prompted by any information concerning the Company or its subsidiaries which is not set forth in the Time of Sale Prospectus to sell its Shares pursuant to this Agreement.

     3. Agreements to Sell and Purchase. Each Seller, severally and not jointly, hereby agrees to sell to the several Underwriters, and each Underwriter, upon the basis of the representations and warranties herein contained, but subject to the conditions hereinafter stated, agrees, severally and not jointly, to purchase from such Seller at $___a share (the “Purchase Price”) the number of Firm Shares (subject to such adjustments to eliminate fractional shares as you may determine) that bears the same proportion to the number of Firm Shares to be sold by such Seller as the number of Firm Shares set forth in Schedule II hereto opposite the name of such Underwriter bears to the total number of Firm Shares.

     On the basis of the representations and warranties contained in this Agreement, and subject to its terms and conditions, the Company agrees to sell to the Underwriters the Additional Shares, and the Underwriters shall have the right to purchase, severally and not jointly, up to 865,000 Additional Shares at the Purchase Price. You may exercise this right on behalf of the Underwriters in whole or from time to time in part by giving written notice not later than 30 days after the date of this Agreement. Any exercise notice shall specify the number of Additional Shares to be purchased by the Underwriters and the date on which such shares are to be purchased. Each purchase date must be at least one business day after the written notice is given and may not be earlier than the closing date for the Firm Shares nor later than ten business days after the date of such notice. Additional Shares may be purchased as provided in Section 5 hereof solely for the purpose of covering over-allotments made in connection with the offering of the Firm Shares. On each day, if any, that Additional Shares are to be purchased (an “Option Closing Date”), each Underwriter agrees, severally and not jointly, to purchase the number of Additional Shares (subject to such adjustments to eliminate fractional shares as you may determine) that bears the same proportion to the total number of Additional Shares to be purchased on such Option Closing Date as the number of Firm Shares set forth in Schedule II hereto opposite the name of such Underwriter bears to the total number of Firm Shares.

     The Company hereby agrees that, without the prior written consent of ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ on behalf of the Underwriters, it will not, during the period ending 180 days after the date of the Prospectus, (1) offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock or (2) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of the Common Stock, whether any such transaction described in clause (1) or (2) above is to be settled by delivery of Common Stock or such other securities, in cash or otherwise or (3) file any registration statement with the Commission relating to the offering of any

shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock, except for registration statements on Form S-8 (or equivalent forms).

The restrictions contained in the preceding paragraph shall not apply to (a) the Shares to be sold hereunder, (b) the issuance by the Company of restricted shares of Common Stock or options to acquire Common Stock pursuant to the Company’s employee benefit plans, stock option plans or other employee compensation plans described in the Prospectus, (c) the issuance by the Company of shares of Common Stock upon the exercise of an option that was issued pursuant to the Company’s employee benefit plans, stock option plans or other employee compensation plans described in the Prospectus, (d) the issuance by the Company of shares of Common Stock upon exercise of a warrant or the conversion of a security outstanding on the date hereof that has been disclosed in the Prospectus or of which the Underwriters have been advised in writing, or (e) the issuance by the Company of up to an aggregate of three hundred thousand (300,000) shares of Common Stock (or securities convertible into or exercisable or exchangeable for Common Stock) in connection with acquisitions or other business combinations, strategic alliances or similar relationships, including, without limitation, relationships with original equipment manufacturers, distributors, resellers and suppliers; provided that such recipient shall sign and deliver a lock-up agreement in the form attached hereto as Exhibit A. Notwithstanding the foregoing, if (1) during the last 17 days of the 180-day restricted period the Company issues an earnings release or material news or a material event relating to the Company occurs; or (2) prior to the expiration of the 180-day restricted period, the Company announces that it will release earnings results during the 16-day period beginning on the last day of the 180-day period, the restrictions imposed by the preceding paragraph shall continue to apply until the expiration of the 18-day period beginning on the issuance of the earnings release or the occurrence of the material news or material event. The Company shall promptly notify ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ of any earnings release, news or event that may give rise to an extension of the initial 180-day restricted period.

     4. Terms of Public Offering. The Sellers are advised by you that the Underwriters propose to make a public offering of their respective portions of the Shares as soon after the Registration Statement and this Agreement have become effective as in your judgment is advisable. The Sellers are further advised by you that the Shares are to be offered to the public initially at $___a share (the “Public Offering Price”) and to certain dealers selected by you at a price that represents a concession not in excess of $___a share under the Public Offering Price, and that any Underwriter may allow, and such dealers may reallow, a concession, not in excess of $___a share, to any Underwriter or to certain other dealers.

     5. Payment and Delivery. Payment for the Firm Shares to be sold by each Seller shall be made to the Company in Federal or other funds immediately available in New York City against delivery of such Firm Shares for the respective accounts of the several Underwriters at 10:00 a.m., New York City

time, on                     , 2007, or at such other time on the same or such other date, not later than                     , 2007, as shall be designated in writing by you. The time and date of such payment are hereinafter referred to as the “Closing Date.”

     Payment for any Additional Shares shall be made to each Seller in Federal or other funds immediately available in New York City against delivery of such Additional Shares for the respective accounts of the several Underwriters at 10:00 a.m., New York City time, on the date specified in the corresponding notice described in Section 3 or at such other time on the same or on such other date, in any event not later than ___, 2007, as shall be designated in writing by you.

     The Firm Shares and Additional Shares shall be registered in such names and in such denominations as you shall request in writing not later than one full business day prior to the Closing Date or the applicable Option Closing Date, as the case may be. The Firm Shares and Additional Shares shall be delivered to you on the Closing Date or an Option Closing Date, as the case may be, for the respective accounts of the several Underwriters, with any transfer taxes payable in connection with the transfer of the Shares to the Underwriters duly paid, against payment of the Purchase Price therefor.

     6. Conditions to the Underwriters’ Obligations. The obligations of the Sellers to sell the Shares to the Underwriters and the several obligations of the Underwriters to purchase and pay for the Shares on the Closing Date are subject to the condition that the Registration Statement shall have become effective not later than [                    ] (New York City time) on the date hereof.

     The several obligations of the Underwriters are subject to the following further conditions:

     (a) Subsequent to the execution and delivery of this Agreement and prior to the Closing Date there shall not have occurred any change, or any development involving a prospective change, in the condition, financial or otherwise, or in the earnings, business or operations of the Company and its subsidiaries, taken as a whole, from that set forth in the Time of Sale Prospectus that, in your judgment, is material and adverse and that makes it, in your judgment, impracticable to market the Shares on the terms and in the manner contemplated in the Time of Sale Prospectus.

     (b) The Underwriters shall have received on the Closing Date a certificate, dated the Closing Date and signed by the chief executive officer of the Company, to the effect that the representations and warranties of the Company contained in this Agreement are true and correct as of the Closing Date (including, with respect to the representation and warranty in Section 1(b) hereof, a representation by the chief executive officer in his personal capacity) and that the Company has complied in all material respects with all of the agreements and

satisfied in all material respects all of the conditions on its part to be performed or satisfied hereunder on or before the Closing Date.

     The officer signing and delivering such certificate may rely upon the best of his or her knowledge as to proceedings threatened.

     (c) The Underwriters shall have received on the Closing Date an opinion of ▇▇▇▇▇▇▇▇ & ▇▇▇▇▇▇▇▇ LLP, outside counsel for the Company, dated the Closing Date, in the form set forth in Exhibit B hereto.

     (d) The Underwriters shall have received on the Closing Date an opinion of ▇▇▇▇ Law Group, PLC, special counsel for the Company with respect to the Intellectual Property, addressed to the Underwriters, and in form and substance satisfactory to ▇▇▇▇▇▇ & ▇▇▇▇▇▇▇ LLP, counsel for the Underwriters, in the form set forth in Exhibit C hereto.

     (e) The Underwriters shall have received on the Closing Date an opinion of counsel for each of the Selling Shareholders, dated the Closing Date, to the effect that:

     (i) The Underwriting Agreement has been duly authorized, executed and delivered by or on behalf of each of the Selling Shareholders;

     (ii) the execution and delivery by each Selling Shareholder of this Agreement, the Custody Agreement and the Power of Attorney and the sale of such Selling Shareholder’s Shares pursuant to this Agreement will not violate any provision of applicable law, which, in our experience is typically applicable to transactions of the nature contemplated by this Agreement, Custody Agreement and Power of Attorney and is applicable to the Selling Shareholder, or the certificate of incorporation or by-laws of such Selling Shareholder (if such Selling Shareholder is a corporation), or, to such counsel’s knowledge, any agreement or other instrument known to such counsel to be binding upon such Selling Shareholder or, any judgment, order or decree known to such counsel to be applicable to such Selling Shareholder of any governmental body, agency or court having jurisdiction over such Selling Shareholder, and no consent, approval, authorization or order of, or qualification with, any governmental body or agency is required for the sale of such Selling Shareholder’s Shares under this Agreement, except such as may have been obtained under the 1933 Act and such as may be required under the Blue Sky laws of any jurisdiction in connection with the purchase and distribution of the Selling Shareholder’s Shares by the Underwriters;

     (iii) each of the Selling Shareholders has the legal right and power, and all authorization and approval required by law, to enter into this Agreement and the Custody Agreement and Power of Attorney of

such Selling Shareholder and to sell, transfer and deliver the Shares to be sold by such Selling Shareholder or a security entitlement in respect of such Shares;

     (iv) the Custody Agreement and the Power of Attorney of each Selling Shareholder have been duly authorized, executed and delivered by such Selling Shareholder and are valid and binding agreements of such Selling Shareholder except as to rights to indemnity under the Custody Agreement and Power of Attorney may be limited by applicable laws and except as enforcement may be limited by applicable bankruptcy, insolvency, reorganization, arrangement, moratorium or other similar laws affecting creditor’s rights, and subject to general equity principles and to limitations on availability of equitable relief, including specific performance;

     (v) Upon indication by book entry that the Shares to be sold by the Selling Shareholder pursuant to the Underwriting Agreement have been credited to a securities account maintained by the Underwriters at the DTC and payment therefor in accordance with the Underwriting Agreement (assuming that the Underwriters do not have “notice of any adverse claim” (within the meaning of Section 8-105 of the UCC) to such Shares), (A) under Section 8-501 of the UCC, the Underwriters will acquire a valid security entitlement with respect to such Shares and (B) no action based on any “adverse claim” (within the meaning of Section 8-102 of the UCC) to such Shares may be asserted against any Underwriter with respect to such security entitlement; in giving this opinion we have assumed that DTC is a securities intermediary as defined in Section 8-102(14) of the UCC.

     (f) The Underwriters shall have received on the Closing Date an opinion of ▇▇▇▇▇▇ & ▇▇▇▇▇▇▇ LLP, counsel for the Underwriters, dated the Closing Date, with respect to the validity of the Shares, the Registration Statements, the Prospectus and such other matters as the Representatives may require.

     ▇▇▇▇▇▇▇▇ & ▇▇▇▇▇▇▇▇ LLP and ▇▇▇▇▇▇ & ▇▇▇▇▇▇▇ LLP and with respect to Section 6(e)(vi) above, counsel for each of the Selling Shareholders, may state that their opinions and beliefs are based upon their participation in the preparation of the Registration Statement, the Time of Sale Prospectus and the Prospectus and any amendments or supplements thereto and review and discussion of the contents thereof, but are without independent check or verification, except as specified. With respect to Section 6(d) above, counsel for each of the Selling Shareholders may rely upon an opinion or opinions of counsel for any Selling Shareholders and, with respect to factual matters and to the extent such counsel deems appropriate, upon the representations of each Selling Shareholder contained herein and in the Custody Agreement and Power of Attorney of such Selling Shareholder and in other documents and instruments;

provided that (A) each such counsel for the Selling Shareholders is satisfactory to your counsel, (B) a copy of each opinion so relied upon is delivered to you and is in form and substance satisfactory to your counsel, (C) copies of such Custody Agreements and Powers of Attorney and of any such other documents and instruments shall be delivered to you and shall be in form and substance satisfactory to your counsel and (D) counsel for each of the Selling Shareholders shall state in their opinion that they are justified in relying on each such other opinion.

     The opinions of ▇▇▇▇▇▇▇▇ & ▇▇▇▇▇▇▇▇ LLP, ▇▇▇▇ Law Group, PLC and counsel for each of the Selling Shareholders described in Sections 6(c), 6(d) and 6(e) above (and any opinions of counsel for any Selling Shareholder referred to in the immediately preceding paragraph) shall be rendered to the Underwriters at the request of the Company or one or more of the Selling Shareholders, as the case may be, and shall so state therein.

     (g) The Underwriters shall have received, on each of the date hereof with respect to the Time of Sale Prospectus, the date of the Prospectus with respect to the Prospectus and the Closing Date, a letter dated the date hereof or the Closing Date, as the case may be, in form and substance reasonably satisfactory to the Underwriters, from Ernst & Young LLP, independent public accountants, containing statements and information of the type ordinarily included in accountants’ “comfort letters” to underwriters with respect to the financial statements and certain financial information contained in the Registration Statement, the Time of Sale Prospectus and the Prospectus; provided that the letter delivered on the Closing Date shall use a “cut-off date” not earlier than the date hereof.

     (h) The “lock-up” agreements, each substantially in the form of Exhibit A hereto, between you and certain shareholders, officers and directors of the Company relating to sales and certain other dispositions of shares of Common Stock or certain other securities, delivered to you on or before the date hereof, shall be in full force and effect on the Closing Date.

     The several obligations of the Underwriters to purchase Additional Shares hereunder are subject to the delivery to you on the applicable Option Closing Date of such documents as you may reasonably request with respect to the good standing of the Company, the due authorization and issuance of the Additional Shares to be sold on such Option Closing Date and other matters related to the issuance of such Additional Shares.

     7. Covenants of the Company. The Company covenants with each Underwriter as follows:

     (a) To furnish to you, without charge, five signed copies of the Registration Statement (including exhibits thereto) and for delivery to each other Underwriter a conformed copy of the Registration Statement (without exhibits

thereto) and to furnish to you in New York City, without charge, prior to 10:00 a.m. New York City time on the business day next succeeding the date of this Agreement and during the period mentioned in Sections 7(e) or 7(f) below, as many copies of the Time of Sale Prospectus, the Prospectus and any supplements and amendments thereto or to the Registration Statement as you may reasonably request.

     (b) Before amending or supplementing the Registration Statement, the Time of Sale Prospectus or the Prospectus, to furnish to you a copy of each such proposed amendment or supplement and not to file any such proposed amendment or supplement to which you promptly and reasonably object, and to file with the Commission within the applicable period specified in Rule 424(b) under the Securities Act any prospectus required to be filed pursuant to such Rule.

     (c) To furnish to you a copy of each proposed free writing prospectus to be prepared by or on behalf of, used by, or referred to by the Company and not to use or refer to any proposed free writing prospectus to which you promptly and reasonably object.

     (d) Not to take any action that would result in an Underwriter or the Company being required to file with the Commission pursuant to Rule 433(d) under the Securities Act a free writing prospectus prepared by or on behalf of the Underwriter that the Underwriter otherwise would not have been required to file thereunder.

     (e) If the Time of Sale Prospectus is being used to solicit offers to buy the Shares at a time when the Prospectus is not yet available to prospective purchasers and any event shall occur or condition exist as a result of which it is necessary to amend or supplement the Time of Sale Prospectus in order to make the statements therein, in the light of the circumstances, not misleading, or if any event shall occur or condition exist as a result of which the Time of Sale Prospectus conflicts with the information contained in the Registration Statement then on file, or if, in the opinion of counsel for the Underwriters after consultation with counsel for the Company, it is necessary to amend or supplement the Time of Sale Prospectus to comply with applicable law, forthwith to prepare, file with the Commission and furnish, at its own expense, to the Underwriters and to any dealer upon request, either amendments or supplements to the Time of Sale Prospectus so that the statements in the Time of Sale Prospectus as so amended or supplemented will not, in the light of the circumstances when the Time of Sale Prospectus is delivered to a prospective purchaser, be misleading or so that the Time of Sale Prospectus, as amended or supplemented, will no longer conflict with the Registration Statement, or so that the Time of Sale Prospectus, as amended or supplemented, will comply with applicable law.

     (f) If, during such period after the first date of the public offering of the Shares as in the reasonable opinion of counsel for the Underwriters after consultation with counsel for the Company, the Prospectus (or in lieu thereof the

notice referred to in Rule 173(a) of the Securities Act) is required by law to be delivered in connection with sales by an Underwriter or dealer, any event shall occur or condition exist as a result of which it is necessary to amend or supplement the Prospectus in order to make the statements therein, in the light of the circumstances when the Prospectus (or in lieu thereof the notice referred to in Rule 173(a) of the Securities Act) is delivered to a purchaser, not misleading, or if, in the opinion of counsel for the Underwriters after consultation with counsel for the Company, it is necessary to amend or supplement the Prospectus to comply with applicable law, forthwith to prepare, file with the Commission and furnish, at its own expense, to the Underwriters after consultation with counsel for the Company, and to the dealers (whose names and addresses you will furnish to the Company) to which Shares may have been sold by you on behalf of the Underwriters and to any other dealers upon request, either amendments or supplements to the Prospectus so that the statements in the Prospectus as so amended or supplemented will not, in the light of the circumstances when the Prospectus (or in lieu thereof the notice referred to in Rule 173(a) of the Securities Act) is delivered to a purchaser, be misleading or so that the Prospectus, as amended or supplemented, will comply with applicable law.

     (g) To endeavor to qualify the Shares for offer and sale under the securities or Blue Sky laws of such jurisdictions as you shall reasonably request.

     (h) To make generally available to the Company’s security holders and to you as soon as practicable an earning statement covering a period of at least twelve months beginning with the first fiscal quarter of the Company occurring after the date of this Agreement which shall satisfy the provisions of Section 11(a) of the Securities Act and the rules and regulations of the Commission thereunder.

     8. Expenses. Whether or not the transactions contemplated in this Agreement are consummated or this Agreement is terminated, the Company agrees to pay or cause to be paid all expenses incident to the performance of their obligations under this Agreement, including: (i) the fees, disbursements and expenses of the Company’s counsel, the Company’s accountants [and one firm of counsel for the Selling Shareholders in connection with the registration and delivery of the Shares under the Securities Act] and all other fees or expenses in connection with the preparation and filing of the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, the Prospectus, any free writing prospectus prepared by or on behalf of, used by, or referred to by the Company and amendments and supplements to any of the foregoing, including all printing costs associated therewith, and the mailing and delivering of copies thereof to the Underwriters and dealers, in the quantities hereinabove specified, (ii) all costs and expenses related to the transfer and delivery of the Shares to the Underwriters, including any transfer or other taxes payable thereon, (iii) the cost of printing or producing any Blue Sky or Legal Investment memorandum in connection with the offer and sale of the Shares under state securities laws and all expenses in connection with the qualification of the Shares for offer and sale

under state securities laws as provided in Section 7(g) hereof, including filing fees and the reasonable fees and disbursements of counsel for the Underwriters in connection with such qualification, which fees and disbursement shall not exceed $5,000 and in connection with the Blue Sky or Legal Investment memorandum, (iv) all filing fees and the reasonable fees and disbursements of counsel to the Underwriters incurred in connection with the review and qualification of the offering of the Shares by the National Association of Securities Dealers, Inc., (v) all fees and expenses in connection with the preparation and filing of the registration statement on Form 8-A relating to the Common Stock and all costs and expenses incident to qualification for quotation of the Shares on the Nasdaq Global Market, (vi) the cost of printing certificates representing the Shares, (vii) the costs and charges of any transfer agent, registrar or depositary, (viii) the costs and expenses of the Company relating to investor presentations on any “road show” undertaken in connection with the marketing of the offering of the Shares, including, without limitation, expenses associated with the preparation or dissemination of any electronic roadshow, expenses associated with the production of road show slides and graphics, fees and expenses of any consultants engaged in connection with the road show presentations with the prior approval of the Company, travel and lodging expenses of the representatives and officers of the Company and any such consultants, and one-half of the cost of any aircraft chartered in connection with the road show, (ix) the document production charges and expenses associated with printing this Agreement, and (x) all other costs and expenses incident to the performance of the obligations of the Company hereunder for which provision is not otherwise made in this Section. It is understood, however, that except as provided in this Section, Section 10 entitled “Indemnity and Contribution” and the last paragraph of Section 13 below, the Underwriters will pay all of their costs and expenses, including fees and disbursements of their counsel, stock transfer taxes payable on resale of any of the Shares by them and any advertising expenses connected with any offers they may make.

     The provisions of this Section shall not supersede or otherwise affect any agreement that the Sellers may otherwise have for the allocation of such expenses among themselves.

     9. Covenants of the Underwriters. Each Underwriter severally covenants with the Company not to take any action that would result in the Company being required to file with the Commission under Rule 433(d) a free writing prospectus prepared by or on behalf of such Underwriter that otherwise would not be required to be filed by the Company thereunder, but for the action of the Underwriter.

     10. Indemnity and Contribution. (a) The Company agrees to indemnify and hold harmless each Underwriter, each person, if any, who controls any Underwriter within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act, and each affiliate of any Underwriter within the meaning of Rule 405 under the Securities Act from and against any and all losses,

claims, damages and liabilities (including, without limitation, any legal or other expenses reasonably incurred in connection with defending or investigating any such action or claim) caused by any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or any amendment thereof, any preliminary prospectus, the Time of Sale Prospectus, any issuer free writing prospectus as defined in Rule 433(h) under the Securities Act, any Company information that the Company has filed, or is required to file, pursuant to Rule 433(d) of the Securities Act, or the Prospectus or any amendment or supplement thereto, or caused by any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, except insofar as such losses, claims, damages or liabilities are caused by any such untrue statement or omission or alleged untrue statement or omission based upon information relating to any Underwriter furnished to the Company in writing by such Underwriter through you expressly for use therein.

     (b) Each Selling Shareholder, severally and not jointly agrees to indemnify and hold harmless each Underwriter, each person, if any, who controls any Underwriter within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act, and each affiliate of any Underwriter within the meaning of Rule 405 under the Securities Act to the extent and in the manner set forth in clause (a) above, but only to the extent that the untrue statement or alleged untrue statement or omission or alleged omission was made in reliance upon and in conformity the Provided Information. The total liability of each Selling Shareholder under the indemnity agreement contained in this paragraph and under the contribution agreement contained in paragraphs (e) and (f) below shall be limited to an amount equal to the gross proceeds of such Selling Shareholder from sales of the Shares sold by such Selling Shareholder under this Agreement after deducting underwriting discounts and commissions.

     (c) Each Underwriter agrees, severally and not jointly, to indemnify and hold harmless the Company, the Selling Shareholders, the directors of the Company, the officers of the Company who sign the Registration Statement and each person, if any, who controls the Company or any Selling Shareholder within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act from and against any and all losses, claims, damages and liabilities (including, without limitation, any legal or other expenses reasonably incurred in connection with defending or investigating any such action or claim) caused by any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or any amendment thereof, any preliminary prospectus, the Time of Sale Prospectus, any issuer free writing prospectus as defined in Rule 433(h) under the Securities Act, any Company information that the Company has filed, or is required to file, pursuant to Rule 433(d) of the Securities Act, or the Prospectus (as amended or supplemented if the Company shall have furnished any amendments or supplements thereto), or caused by any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, but only with

reference to information relating to such Underwriter furnished to the Company in writing by such Underwriter through you expressly for use in the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, any issuer free writing prospectus or the Prospectus or any amendment or supplement thereto.

     (d) In case any proceeding (including any governmental investigation) shall be instituted involving any person in respect of which indemnity may be sought pursuant to Section 10(a), 10(b) or 10(c), such person (the “indemnified party”) shall promptly notify the person against whom such indemnity may be sought (the “indemnifying party”) in writing and the indemnifying party, upon request of the indemnified party, shall retain counsel reasonably satisfactory to the indemnified party to represent the indemnified party and any others the indemnifying party may designate in such proceeding and shall pay the fees and disbursements of such counsel related to such proceeding. In any such proceeding, any indemnified party shall have the right to retain its own counsel, but the fees and expenses of such counsel shall be at the expense of such indemnified party unless (i) the indemnifying party and the indemnified party shall have mutually agreed to the retention of such counsel or (ii) the named parties to any such proceeding (including any impleaded parties) include both the indemnifying party and the indemnified party and representation of both parties by the same counsel would be inappropriate due to actual or potential differing interests between them. It is understood that the indemnifying party shall not, in respect of the legal expenses of any indemnified party in connection with any proceeding or related proceedings in the same jurisdiction, be liable for (i) the fees and expenses of more than one separate firm (in addition to any local counsel) for all Underwriters and all persons, if any, who control any Underwriter within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act or who are affiliates of any Underwriter within the meaning of Rule 405 under the Securities Act, (ii) the fees and expenses of more than one separate firm (in addition to any local counsel) for the Company, its directors, its officers who sign the Registration Statement and each person, if any, who controls the Company within the meaning of either such Section and (iii) the fees and expenses of more than one separate firm (in addition to any local counsel) for all Selling Shareholders and all persons, if any, who control any Selling Shareholder within the meaning of either such Section, and that all such fees and expenses shall be reimbursed as they are incurred. In the case of any such separate firm for the Underwriters and such control persons and affiliates of any Underwriters, such firm shall be designated in writing by ▇▇▇▇▇▇ ▇▇▇▇▇▇▇. In the case of any such separate firm for the Company, and such directors, officers and control persons of the Company, such firm shall be designated in writing by the Company. In the case of any such separate firm for the Selling Shareholders and such control persons of any Selling Shareholders, such firm shall be designated in writing by the persons named as attorneys-in-fact for the Selling Shareholders under the Powers of Attorney. The indemnifying party shall not be liable for any settlement of any proceeding effected without its written consent, but if settled with such consent or if there be a final non-appealable judgment for the plaintiff, the

indemnifying party agrees to indemnify the indemnified party from and against any loss or liability by reason of such settlement or judgment. Notwithstanding the foregoing sentence, if at any time an indemnified party shall have requested an indemnifying party to reimburse the indemnified party for fees and expenses of counsel as contemplated by the second and third sentences of this paragraph, the indemnifying party agrees that it shall be liable for any settlement of any proceeding effected without its written consent if (i) such settlement is entered into more than 30 days after receipt by such indemnifying party of the aforesaid request and (ii) such indemnifying party shall not have reimbursed the indemnified party in accordance with such request prior to the date of such settlement. No indemnifying party shall, without the prior written consent of the indemnified party, effect any settlement of any pending or threatened proceeding in respect of which any indemnified party is or could have been a party and indemnity could have been sought hereunder by such indemnified party, unless such settlement includes an unconditional release of such indemnified party from all liability on claims that are the subject matter of such proceeding.

     (e) To the extent the indemnification provided for in Section 10(a), 10(b) or 10(c) is unavailable to an indemnified party or insufficient in respect of any losses, claims, damages or liabilities referred to therein, then each indemnifying party under such paragraph, in lieu of indemnifying such indemnified party thereunder, shall contribute to the amount paid or payable by such indemnified party as a result of such losses, claims, damages or liabilities (i) in such proportion as is appropriate to reflect the relative benefits received by the indemnifying party or parties on the one hand and the indemnified party or parties on the other hand from the offering of the Shares or (ii) if the allocation provided by clause 10(e)(i) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause 10(e)(i) above but also the relative fault of the indemnifying party or parties on the one hand and of the indemnified party or parties on the other hand in connection with the statements or omissions that resulted in such losses, claims, damages or liabilities, as well as any other relevant equitable considerations. The relative benefits received by the Sellers on the one hand and the Underwriters on the other hand in connection with the offering of the Shares shall be deemed to be in the same respective proportions as the net proceeds from the offering of the Shares (before deducting expenses) received by each Seller and the total underwriting discounts and commissions received by the Underwriters, in each case as set forth in the table on the cover of the Prospectus, bear to the aggregate Public Offering Price of the Shares. The relative fault of the Sellers on the one hand and the Underwriters on the other hand shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Sellers or by the Underwriters and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission. The Underwriters’ respective obligations to contribute pursuant to this Section 10 are several in proportion to the respective number of Shares they have purchased hereunder, and not joint. The total liability of each

Selling Shareholder under the contribution agreement contained in this paragraph and paragraph (e) below and under the indemnity agreement contained in paragraph (a) above shall be limited to an amount equal to the gross proceeds of such Selling Shareholder from sales of the Shares sold by such Selling Shareholder under this Agreement after deducting underwriting discounts and commissions.

     (f) The Sellers and the Underwriters agree that it would not be just or equitable if contribution pursuant to this Section 10 were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation that does not take account of the equitable considerations referred to in Section 10(e). The amount paid or payable by an indemnified party as a result of the losses, claims, damages and liabilities referred to in Section 10(e) shall be deemed to include, subject to the limitations set forth above, any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending any such action or claim. Notwithstanding the provisions of this Section 10, no Underwriter shall be required to contribute any amount in excess of the amount by which the total price at which the Shares underwritten by it and distributed to the public were offered to the public exceeds the amount of any damages that such Underwriter has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The remedies provided for in this Section 10 are not exclusive and shall not limit any rights or remedies which may otherwise be available to any indemnified party at law or in equity.

     (g) The indemnity and contribution provisions contained in this Section 10 and the representations, warranties and other statements of the Company and the Selling Shareholders contained in this Agreement shall remain operative and in full force and effect regardless of (i) any termination of this Agreement, (ii) any investigation made by or on behalf of any Underwriter, any person controlling any Underwriter or any affiliate of any Underwriter, any Selling Shareholder or any person controlling any Selling Shareholder, or the Company, its officers or directors or any person controlling the Company and (iii) acceptance of and payment for any of the Shares.

     11. Termination. The Underwriters may terminate this Agreement by written notice given by you to the Company, if after the execution and delivery of this Agreement and prior to the Closing Date (i) trading generally shall have been suspended or materially limited on, or by, as the case may be, any of the New York Stock Exchange, the American Stock Exchange, the Nasdaq Global Market, the Chicago Board of Options Exchange, the Chicago Mercantile Exchange or the Chicago Board of Trade or other relevant exchanges, (ii) trading of any securities of the Company shall have been suspended on any exchange or in any over-the-counter market, (iii) a material disruption in securities settlement,

payment or clearance services in the United States shall have occurred, (iv) any moratorium on commercial banking activities shall have been declared by Federal or New York State authorities or (v) there shall have occurred any outbreak or escalation of hostilities, or any change in financial markets or any calamity or crisis that, in your judgment, is material and adverse and which, singly or together with any other event specified in this clause (v), makes it, in your judgment, impracticable or inadvisable to proceed with the offer, sale or delivery of the Shares on the terms and in the manner contemplated in the Time of Sale Prospectus or the Prospectus.

     12. Effectiveness; Defaulting Underwriters. This Agreement shall become effective upon the execution and delivery hereof by the parties hereto.

     If, on the Closing Date or an Option Closing Date, as the case may be, any one or more of the Underwriters shall fail or refuse to purchase Shares that it has or they have agreed to purchase hereunder on such date, and the aggregate number of Shares which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase is not more than one-tenth of the aggregate number of the Shares to be purchased on such date, the other Underwriters shall be obligated severally in the proportions that the number of Firm Shares set forth opposite their respective names in Schedule II bears to the aggregate number of Firm Shares set forth opposite the names of all such non-defaulting Underwriters, or in such other proportions as you may specify, to purchase the Shares which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase on such date; provided that in no event shall the number of Shares that any Underwriter has agreed to purchase pursuant to this Agreement be increased pursuant to this Section 13 by an amount in excess of one-ninth of such number of Shares without the written consent of such Underwriter. If, on the Closing Date, any Underwriter or Underwriters shall fail or refuse to purchase Firm Shares and the aggregate number of Firm Shares with respect to which such default occurs is more than one-tenth of the aggregate number of Firm Shares to be purchased on such date, and arrangements satisfactory to you, the Company and the Selling Shareholders for the purchase of such Firm Shares are not made within 36 hours after such default, this Agreement shall terminate without liability on the part of any non-defaulting Underwriter, the Company or the Selling Shareholders. In any such case either you or the relevant Sellers shall have the right to postpone the Closing Date, but in no event for longer than seven days, in order that the required changes, if any, in the Registration Statement, in the Time of Sale Prospectus, in the Prospectus or in any other documents or arrangements may be effected. If, on an Option Closing Date, any Underwriter or Underwriters shall fail or refuse to purchase Additional Shares and the aggregate number of Additional Shares with respect to which such default occurs is more than one-tenth of the aggregate number of Additional Shares to be purchased on such Option Closing Date, the non-defaulting Underwriters shall have the option to (i) terminate their obligation hereunder to purchase the Additional Shares to be sold on such Option Closing Date or (ii) purchase not less than the number of Additional Shares that such non-defaulting Underwriters would have been obligated to purchase in the absence of

such default. Any action taken under this paragraph shall not relieve any defaulting Underwriter from liability in respect of any default of such Underwriter under this Agreement.

     If this Agreement shall be terminated because of any failure or refusal on the part of any Seller to comply with the terms or to fulfill any of the conditions of this Agreement, or if for any reason any Seller shall be unable to perform its obligations under this Agreement, such defaulting Sellers will reimburse the Underwriters or such Underwriters as have so terminated this Agreement with respect to themselves, severally, for all out-of-pocket expenses (including the fees and disbursements of their counsel) reasonably incurred by such Underwriters in connection with this Agreement or the offering contemplated hereunder.

     13. Entire Agreement. (a) This Agreement, together with any contemporaneous written agreements and any prior written agreements (to the extent not superseded by this Agreement) that relate to the offering of the Shares, represents the entire agreement between the Company and the Selling Shareholders, on the one hand, and the Underwriters, on the other, with respect to the preparation of any preliminary prospectus, the Time of Sale Prospectus, the Prospectus, the conduct of the offering, and the purchase and sale of the Shares.

     (b) The Company acknowledges that in connection with the offering of the Shares: (i) the Underwriters have acted at arms length, are not agents of, and owe no fiduciary duties to, the Company or any other person, (ii) the Underwriters owe the Company only those duties and obligations set forth in this Agreement and prior written agreements (to the extent not superseded by this Agreement), if any, and (iii) the Underwriters may have interests that differ from those of the Company. The Company waives to the full extent permitted by applicable law any claims it may have against the Underwriters arising from an alleged breach of fiduciary duty in connection with the offering of the Shares.

     14. Counterparts. This Agreement may be signed in two or more counterparts, each of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument.

     15. Applicable Law. This Agreement shall be governed by and construed in accordance with the internal laws of the State of New York.

     16. Headings. The headings of the sections of this Agreement have been inserted for convenience of reference only and shall not be deemed a part of this Agreement.

     17. Notices. All communications hereunder shall be in writing and effective only upon receipt and if to the Underwriters shall be delivered, mailed or sent to you at ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. Incorporated, ▇▇▇▇ ▇▇▇▇▇▇▇▇, ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇, Attention: Equity Syndicate Desk, with a copy to the Legal Department; if to the Company shall be delivered, mailed or sent to Sourcefire,

Inc., ▇▇▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇, ▇▇▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇, with a copy to ▇▇▇▇▇▇ ▇. ▇▇▇▇, Esq., ▇▇▇▇▇▇▇▇ & ▇▇▇▇▇▇▇▇ LLP, ▇▇▇▇ ▇▇▇▇▇▇ ▇▇▇▇., ▇▇▇▇▇ ▇▇▇, ▇▇▇▇▇▇, ▇▇▇▇▇▇▇▇ ▇▇▇▇▇, and if to the Selling Shareholders shall be delivered, mailed or sent to [ ].

Accepted as of the date hereof

▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. Incorporated

Acting severally on behalf of themselves and the several Underwriters named in Schedule II hereto

By: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. Incorporated

By:
		Name:
		Title:

SCHEDULE I

		Number of Firm Shares
Selling Shareholder		To Be Sold
Sierra Ventures
Inflection Point
Core Capital
E. ▇▇▇▇▇ ▇▇▇▇▇▇▇, III
Total:

SCHEDULE II

		Number of Firm Shares
Underwriter		To Be Purchased
▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. Incorporated
▇▇▇▇▇▇ Brothers Inc.
UBS Securities LLC
▇▇▇▇▇▇▇▇▇ & Company, Inc.
Total:

SCHEDULE III

Time of Sale Prospectus

1.		Preliminary Prospectus issued [date]
2.		[identify all free writing prospectuses filed by the Company under Rule 433(d) of the Securities Act]
3.		[free writing prospectus containing a description of terms that does not reflect final terms, if the Time of Sale Prospectus does not include a final term sheet]
4.		[orally communicated pricing information to be included on Schedule III if a final term sheet is not used]

EXHIBIT A

[FORM OF LOCK-UP LETTER]

                    , 2006

▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. Incorporated
▇▇▇▇▇▇ Brothers Inc.
UBS Securities LLC
▇▇▇▇▇▇▇▇ & Company, Inc.
c/o Morgan ▇▇▇▇▇▇▇ & Co. Incorporated
▇▇▇▇ ▇▇▇▇▇▇▇▇
▇▇▇ ▇▇▇▇, ▇▇ ▇▇▇▇▇

Dear Ladies and Gentlemen:

     The undersigned understands that ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ & Co. Incorporated (“▇▇▇▇▇▇ ▇▇▇▇▇▇▇”) proposes to enter into an Underwriting Agreement (the “Underwriting Agreement”) with Sourcefire, Inc., a Delaware corporation (the “Company”), providing for the public offering (the “Public Offering”) by the several Underwriters, including ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ (the “Underwriters”), of [•] shares (the “Shares”) of Common Stock (par value $0.001 per share) of the Company (the “Common Stock”).

     To induce the Underwriters that may participate in the Public Offering to continue their efforts in connection with the Public Offering, the undersigned hereby agrees that, without the prior written consent of ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ on behalf of the Underwriters, it will not, during the period commencing on the date hereof and ending 180 days after the date of the final prospectus relating to the Public Offering (the “Prospectus”), (1) offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock, or (2) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of the Common Stock, whether any such transaction described in clause (1) or (2) above is to be settled by delivery of Common Stock or such other securities, in cash or otherwise. The foregoing sentence shall not apply to (a) transactions relating to shares of Common Stock or other securities acquired in open market transactions after the completion of the Public Offering, provided that no filing under Section 16(a) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) shall be required or shall be voluntarily made in connection with subsequent sales of Common Stock or other securities acquired in such open market transactions, (b) transfers of shares of Common Stock or any security convertible into Common Stock as a

bona fide gift, or (c) distributions of shares of Common Stock or any security convertible into Common Stock to limited partners or stockholders of the undersigned; provided that in the case of any transfer or distribution pursuant to clause (b) or (c), (i) each donee or distributee shall sign and deliver a lock-up letter substantially in the form of this letter and (ii) no filing under Section 16(a) of the Exchange Act, reporting a reduction in beneficial ownership of shares of Common Stock, shall be required or shall be voluntarily made during the restricted period referred to in the foregoing sentence. In addition, the undersigned agrees that, without the prior written consent of ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ on behalf of the Underwriters, it will not, during the period commencing on the date hereof and ending 180 days after the date of the Prospectus, make any demand for or exercise any right with respect to, the registration of any shares of Common Stock or any security convertible into or exercisable or exchangeable for Common Stock. The undersigned also agrees and consents to the entry of stop transfer instructions with the Company’s transfer agent and registrar against the transfer of the undersigned’s shares of Common Stock except in compliance with the foregoing restrictions.

     If:

     (1) during the last 17 days of the restricted period the Company issues an earnings release or material news or a material event relating to the Company occurs; or

     (2) prior to the expiration of the restricted period, the Company announces that it will release earnings results during the 16-day period beginning on the last day of the restricted period;

the restrictions imposed by this agreement shall continue to apply until the expiration of the 18-day period beginning on the issuance of the earnings release or the occurrence of the material news or material event.

     The undersigned shall not engage in any transaction that may be restricted by this agreement during the 34-day period beginning on the last day of the initial restricted period unless the undersigned requests and receives prior written confirmation from the Company or ▇▇▇▇▇▇ ▇▇▇▇▇▇▇ that the restrictions imposed by this agreement have expired.

     The undersigned understands that the Company and the Underwriters are relying upon this agreement in proceeding toward consummation of the Public Offering. The undersigned further understands that this agreement is irrevocable and shall be binding upon the undersigned’s heirs, legal representatives, successors and assigns.

     Whether or not the Public Offering actually occurs depends on a number of factors, including market conditions. Any Public Offering will only be made

pursuant to an Underwriting Agreement, the terms of which are subject to negotiation between the Company and the Underwriters.

		Very truly yours,
		(Name)
		(Address)

EXHIBIT B

[FORM OF ▇▇▇▇▇▇▇▇ & ▇▇▇▇▇▇▇▇ LLP OPINION]

EXHIBIT C

[FORM OF INTELLECTUAL PROPERTY OPINION]

     1. Other than as disclosed in the Time of Sale Prospectus, , counsel has no actual knowledge that the Company lacks or will be unable to obtain the right to use all Intellectual Property material to the business currently conducted by the Company or to the manufacture, use or sale of the Company’s presently proposed products, as described in the Time of Sale Prospectus.

     2. Other than as disclosed in the Time of Sale Prospectus, counsel has no knowledge of any valid and enforceable third party rights to Intellectual Property, including any valid patent claims, that are being or would be infringed by the business currently conducted by the Company or in the manufacture, use, sale, offer for sale or import of the Company’s presently proposed products, as described in the Time of Sale Prospectus.

     3. The statements relating to legal matters, documents or proceedings included in the Registration Statement, the Time of Sale Prospectus and the Prospectus under the captions “Risk Factors—We have been sued by a company claiming that we misappropriated and incorporated its proprietary rights into our RNA Technology...”, “Risk Factors—Our proprietary rights may be difficult to enforce...”, “Risk Factors—Claims that our products infringe the proprietary rights of others could harm our business...”, “Business—Intellectual Property” and “Business—Legal Proceedings” in each case fairly and completely summarize the matters, documents or proceedings referred to therein.

     4. To the best of counsel’s knowledge, the Company has not received any written communication or notice alleging any act of infringement by the Company of any third party patents which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would have a material adverse effect on the Company.