UNDERWRITING AGREEMENT

Exhibit 1.1

EXECUTION COPY

5,000,000 Shares

VOCUS, INC.

COMMON STOCK

UNDERWRITING AGREEMENT

Dated December 6, 2005

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December 6, 2005

Thomas Weisel Partners LLC
RBC Capital Markets Corporation
Wachovia Capital Markets, LLC
William Blair & Company, L.L.C.
As Representatives of the several Underwriters
c/o Thomas Weisel Partners LLC
One Montgomery Street, Suite 3700
San Francisco, California 94104

Ladies and Gentlemen:

      Introduction . Vocus, Inc., a Delaware corporation (the “ Company ”), proposes to issue and sell to the several underwriters named in Schedule A hereto (the “ Underwriters ”), an aggregate of 5,000,000 shares of the common stock, $0.01 par value per share, of the Company (the “ Firm Shares ”).

     Certain stockholders of the Company (the “ Selling Stockholders ”) named in Schedule B hereto severally propose to sell to the several Underwriters an aggregate of 750,000 shares of its common stock, $0.01 par value per share (the “ Additional Shares ”), with each Selling Stockholder selling the number of shares set forth opposite such Selling Stockholder’s name in Schedule B hereto, if and to the extent that you 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, $0.01 par value 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 Stockholders are hereinafter sometimes collectively referred to as the “ Sellers ”. Thomas Weisel Partners LLC, RBC Capital Markets Corporation, Wachovia Capital Markets, LLC and William Blair & Company, L.L.C. have agreed to act as representatives of the several Underwriters (in such capacity, the “ Representatives ”) in connection with the offering and sale of the Shares.

     The Company has prepared and filed with the Securities and Exchange Commission (the “ Commission ”), in accordance with the provisions of the Securities Act of 1933, as amended (the “ Securities Act ”), and the applicable rules and regulations thereunder, a registration statement on Form S-1 (file no. 333-125834), including a prospectus, relating to the Shares. The term “ Registration Statement ” as used herein means the registration statement (including all financial schedules and exhibits) as amended at the time it becomes effective or, if the registration statement became effective prior to the execution of this Agreement, as supplemented or amended prior to the execution of this Agreement and includes information (if any) contained in the final prospectus filed with the Commission pursuant to Rule 424(b) of the rules under the Securities Act and deemed to be part thereof at the time of effectiveness pursuant to Rule 430A of the rules under the Securities Act. If it is contemplated, at the time this Agreement is executed, that a post-effective amendment to the Registration Statement will be filed and must be declared effective before the offering of the Shares may commence, the term “ Registration Statement ” as used herein shall mean the Registration

Statement as amended by such post-effective amendment. If the Company has filed or files on or after the date of this Agreement a registration statement to register additional shares of Common Stock pursuant to Rule 462(b) under the Securities Act (the “ Rule 462(b) Registration Statement ”), then any reference herein to the term “Registration Statement ” shall be deemed to include such Rule 462(b) Registration Statement. Any preliminary prospectus included in the Registration Statement or filed with the Commission pursuant to Rule 424(a) of the rules and regulations of the Commission under the Securities Act is hereinafter called a “ Preliminary Prospectus ”. The term “ Statutory Prospectus ” shall mean any Preliminary Prospectus, as amended or supplemented, relating to the Shares that is included in the Registration Statement immediately prior to the Initial Sale Time (as defined herein), including any document incorporated by reference therein. The term “ Prospectus ” shall mean the final prospectus relating to the Shares that is first filed pursuant to Rule 424(b) after the effective date of the Registration Statement (the “ Effective Date ”) or, if no filing pursuant to Rule 424(b) is required, shall mean the form of final prospectus relating to the Shares included in the Registration Statement at the Effective Date. The term “ Issuer Free Writing Prospectus ” shall have the meaning ascribed to it in Rule 433 under the Securities Act relating to the Shares, in the form filed or required to be filed with the Commission or, if not required to be filed, in the form retained in the Company’s record pursuant to Rule 433(g) under the Securities Act. The term “ Disclosure Package ” shall mean (i) the Statutory Prospectus, (ii) the Issuer Free Writing Prospectus, if any, identified in Schedule C hereto and (iii) any other free writing prospectus defined in Rule 405 of the Securities Act that are required to be filed by the Company with the Commission or retained by the Company under Rule 433 of the Securities Act and that the parties hereto expressly agree to treat as part of the Disclosure Package (the “ Other Free Writing Prospectus ”). For purposes of this Agreement, the “ Initial Sale Time ” shall mean 6:00 p.m. (Eastern Standard Time) on the date of this Agreement. All references in this Agreement to the Registration Statement, the Rule 462(b) Registration Statement, a Preliminary Prospectus, the Statutory Prospectus, the Prospectus, the Issuer Free Writing Prospectus, the Other Free Writing Prospectus or any amendments or supplements to any of the foregoing, shall include any copy thereof filed with the Commission pursuant to its Electronic Data Gathering, Analysis and Retrieval System (“ EDGAR ”).

     As part of the offering contemplated by this Agreement, Thomas Weisel Partners LLC has agreed to reserve out of the Shares set forth opposite its name on Schedule A to this Agreement, up to 250,000 Shares, for sale to parties designated by the Company (collectively, “ Participants ”), as set forth in the Registration Statement, the Statutory Prospectus and the Prospectus under the heading “ Underwriting ” (the “ Directed Share Program ”). The Shares to be sold by Thomas Weisel Partners LLC pursuant to the Directed Share Program (the “ Directed Shares ”) will be sold by Thomas Weisel Partners LLC pursuant to this Agreement at the public offering price. Any Directed Shares not orally confirmed for purchase by any Participants by the end of the first business day after the date on which this Agreement is executed will be offered to the public by Thomas Weisel Partners LLC as set forth in the Registration Statement, the Statutory Prospectus and the Prospectus.

     1.  Representations and Warranties of the Company and Certain of the Selling Stockholders . The Company and each of the Selling Stockholders listed on Schedule D (the “ Company Selling Stockholders ”) jointly and severally represent and warrant to and agree with each of the Underwriters that:

          1.1 Effective Registration Statement . Based on advice from the Commission, 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 knowledge of the Company, threatened by the Commission.

          1.2 Contents of Registration Statement

          (A). (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, the Statutory Prospectus 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, and (iii) the Statutory Prospectus and the Prospectus do 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 Statutory Prospectus or the Prospectus based upon information relating to any Underwriter set forth in the section of the Registration Statement, the Statutory Prospectus or the Prospectus captioned “Underwriting” that was furnished to the Company in writing by such Underwriter through you expressly for use therein and (iv) the statistical and market-related data included in the Registration Statement, Statutory Prospectus and the Prospectus are based on or derived from sources that the Company believes to be reliable and accurate. With respect to the exception set forth at clause (iii) the Company acknowledges that the only information furnished in writing by the Underwriters for use in the Registration Statement or the Prospectus is the statements specifically relating to (a) the aggregate number of Firm Shares that the Underwriters have severally agreed to purchase contained in the first paragraph under the section captioned “Underwriting” in the Registration Statement and the Prospectus, (b) the concession and reallowance figures contained in the paragraph captioned “Commissions and Discounts” under the section caption “Underwriting” in the Registration Statement and the Prospectus, and (c) stabilizing and passive market making activities under the paragraph captioned “Short Sales, Stabilizing Transactions and Penalty Bids” under the section captioned “Underwriting” in the Registration Statement and the Prospectus.

          (B). As of the Initial Sale Time, the Disclosure Package did 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. The preceding sentence does not apply to statements in or omissions from the Disclosure Package based upon and in conformity with written information furnished to the Company by any Underwriter through the Representatives specifically for use therein, it being understood and agreed that the only such information furnished by and Underwriter consists of the information described as such in Section 1.2(A) hereof. No statement of material fact included in the Prospectus has been omitted from the Disclosure Package available at the Initial Sale Time and no statement of material fact included in the Disclosure Package available at the Initial Sale Time that is required to be included in the Prospectus has been omitted therefrom.

          (C). Each Issuer Free Writing Prospectus, as of its issue date and at all subsequent times through the completion of the public offer and sale of the Shares or until any earlier date of which the Company notified or notifies the Representatives as described in the next sentence, did not, does not and will not include any information that conflicted, conflicts or will conflict with the information contained in the Registration Statement, including any document incorporated by reference therein that has not been superseded or modified. If at any time following issuance of an Issuer Free Writing Prospectus, there occurred or occurs an event or development as a result of which such Issuer Free Writing Prospectus conflicted or would conflict with the information then contained in the Registration Statement or included or would include an untrue statement of a material fact or omitted or would omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances prevailing at that

subsequent time, not misleading, (i) the Company has promptly notified or will promptly notify the Representatives and (ii) the Company has promptly amended or will promptly amend or supplement such Issuer Free Writing Prospectus to eliminate or correct such conflict, untrue statement or omission. The foregoing sentences do not apply to statements in or omissions from any Issuer Free Writing Prospectus based upon and in conformity with written information furnished to the Company by any Underwriter through the Representatives specifically for use therein, it being understood and agreed that the only such information furnished by any Underwriter consists of the information described as such in Section 1.2(A) hereof.

          1.3 Due Incorporation . The Company has been duly incorporated, is validly existing as a corporation in good standing under the laws of the State of Delaware, has the corporate power and authority to own its property and to conduct its business as described in the Registration Statement, the Disclosure Package and the 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 individually or in the aggregate, would not have a material adverse effect on the condition (financial or otherwise), results of operations, stockholders’ equity, properties, business or prospects of the Company and its subsidiaries, taken as a whole (a “ Material Adverse Effect ”).

          1.4 Subsidiaries . Each subsidiary of the Company has been duly incorporated or organized, is validly existing as a corporation or other legal entity in good standing (or the foreign equivalent thereof) under the laws of the jurisdiction of its incorporation or organization, has the power and authority to own, lease and operate its property and to conduct its business as described in the Registration Statement, the Disclosure Package and the 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, leasing or operation of property requires such qualification, except to the extent that the failure to be so qualified or be in good standing would not result in a Material Adverse Effect. All of the issued shares of capital stock or other equity interests 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 or through its wholly-owned subsidiaries, free and clear of all liens, encumbrances, equities or claims. There is no outstanding option, right or agreement of any kind relating to the issuance, sale or transfer of any capital stock or other equity securities of the subsidiaries to any person or entity except the Company, and none of the outstanding shares of capital stock or other equity interests of any subsidiary was issued in violation of the preemptive or similar rights of any securityholder of such subsidiary. Except for its subsidiaries, the Company owns no beneficial interest, directly or indirectly, in any corporation, partnership, joint venture or other business entity.

          1.5 Underwriting Agreement . This Agreement has been duly authorized, executed and delivered by the Company, and is a valid and binding agreement of the Company, enforceable in accordance with its terms, except as rights to indemnification hereunder may be limited by applicable law and except as the enforcement hereof may be limited by bankruptcy, insolvency, reorganization, moratorium or other similar laws relating to or affecting the rights and remedies of creditors or by general equitable principles.

          1.6 Description of Capital Stock . The authorized capital stock of the Company conforms as to legal matters to the description thereof contained in the Registration Statement, the Disclosure Package and the Prospectus, and as of the date thereof, the Company had authorized and outstanding capital stock as set forth under the caption “Capitalization” in the Registration Statement, the Statutory Prospectus and the Prospectus.

          1.7 Outstanding Securities . The shares of Common Stock (including the Shares to be sold by the Selling Stockholders) 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 nonassessable. The shares of Common Stock outstanding prior to the issuance of the Shares to be sold by the Company are not subject to preemptive or similar rights to subscribe for or to purchase or acquire any shares of Common Stock of the Company or any of its subsidiaries or any such rights pursuant to its certificate of incorporation or bylaws (each, as amended) or any agreement or instrument to or by which the Company or any of its subsidiaries is a party or bound. Except as disclosed in the Registration Statement, the Statutory Prospectus and the Prospectus, the Company has not sold or issued any securities during the six-month period preceding the date of the Prospectus, including any sales pursuant to Rule 144A under, or Regulations 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 described in the Registration Statement, the Statutory Prospectus and the Prospectus.

          1.8 Validly Issued Shares . 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 nonassessable, and the issuance of such Shares will not be subject to any preemptive or similar rights to subscribe for or to purchase or acquire any shares of Common Stock of the Company or any of its subsidiaries or any such rights pursuant to its certificate of incorporation or bylaws or any agreement or instrument to or by which the Company or any of its subsidiaries is a party or bound.

          1.9 Nasdaq; Exchange Act Registration . The Shares have been duly authorized for quotation on the National Association of Securities Dealers Automated Quotation (“ Nasdaq ”) National Market System, subject to official notice of issuance. A registration statement has been filed on Form 8-A pursuant to Section 12 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act ”), which complies in all material respects with the Exchange Act. The Company has taken no action designed to, or likely to have the effect of, terminating the registration of the Common Stock under the Exchange Act or the quotation of the Common Stock on the Nasdaq National Market System, nor has the Company received any notification that the Commission or the Nasdaq National Market is contemplating terminating such registration or quotation.

          1.10 No Conflict . The execution and delivery by the Company of, and the performance by the Company of its obligations under, this Agreement will not contravene any provision of applicable law or the certificate of incorporation or bylaws (each, as amended) of the Company or (with or without notice or lapse of time or both) 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 any judgment, order or decree of any governmental body, agency or court having jurisdiction over the Company or any subsidiary, 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 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.

          1.11 No Material Adverse Effect . There has not occurred any Material Adverse Effect, or any development involving a prospective Material Adverse Effect, from that set forth in each of the Disclosure Package and the Prospectus (exclusive of any amendments or supplements thereto subsequent to the date of this Agreement).

          1.12 Legal Proceedings; Statutes and Regulations . There are no legal or governmental proceedings pending or, to the knowledge of the Company, 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 that are required to be described in the Registration Statement, the Statutory Prospectus or the Prospectus and are not so described or any statutes or regulations that are required to be described in the Registration Statement, the Statutory Prospectus or the Prospectus and are not described as required.

          1.13 Contracts . There are no contracts or other documents that are required to be described in the Registration Statement, the Statutory Prospectus and Prospectus or filed as exhibits to the Registration Statement by the Securities Act or the applicable rules and regulations thereunder that have not been described in the Registration Statement, the Statutory Prospectus and the Prospectus or filed as exhibits to the Registration Statement.

          1.14 Related Party Transactions . No relationship, direct or indirect, exists between or among the Company, on the one hand, and the directors, officers, stockholders, customers or suppliers of the Company, on the other hand, which is required to be described in the Registration Statement, the Statutory Prospectus and the Prospectus and which is not so described. There are no outstanding loans, advances or guarantees of indebtedness by the Company to or for the benefit of any of the officers or directors of the Company or any of their respective family members, except as disclosed in the Registration Statement, the Statutory Prospectus and the Prospectus.

          1.15 Compliance with Securities Act . 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.

          1.16 Not an Investment Company . 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 Registration Statement, the Disclosure Package and the Prospectus, will not be an “investment company” as such term is defined in the Investment Company Act of 1940, as amended.

          1.17 No Violation . The Company is not in violation of its certificate of incorporation or bylaws (each, as amended), and is not in default, nor any event has occurred which with notice or lapse of time or both would constitute a default, in the performance or observance of any material obligation, agreement, covenant or condition contained in any indenture, mortgage, deed of trust, loan agreement, lease or other agreement or instrument to which it is a party or by which it or any of its properties may be bound, or any license, permit, judgment, decree, order, statute, rule or regulation to which it or any of its properties or its business, or a subsidiary or its properties or business, may be subject, which would result in a Material Adverse Effect.

          1.18 Compliance with Environmental Laws . The Company and its subsidiaries (i) are in compliance with any and all applicable foreign, federal, state and local laws, orders, rules, regulations, directives, decrees and judgments 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, individually or in the aggregate, result in a Material Adverse Effect.

          1.19 No Environmental Costs . 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, individually or in the aggregate, result in a Material Adverse Effect.

          1.20 No Registration Rights . There are no contracts, agreements or understandings between the Company and any person or entity granting such person or entity the right, contractually or otherwise, 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 other than as described in the Registration Statement, the Statutory Prospectus and the Prospectus or as have been waived in writing in connection with the offering contemplated hereby.

          1.21 Absence of Material Charges . Subsequent to the respective dates as of which information is given in the Registration Statement, the Statutory Prospectus and the Prospectus, (i) the Company and its subsidiaries have not incurred any material liability or obligation, direct or contingent, nor entered into any material transaction not in the ordinary course of business; (ii) except as disclosed in the Registration Statement, the Statutory Prospectus and the Prospectus, neither the Company nor its subsidiaries has purchased any of the Company’s outstanding capital stock, nor declared, paid or otherwise made any dividend or distribution of any kind on the Company’s capital stock; 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 described in the Registration Statement, the Statutory Prospectus and the Prospectus.

          1.22 Good Title to Properties . The Company and its subsidiaries do not own any real property. The Company and its subsidiaries have good and valid title to all personal property owned by them which is material to the business of the Company and its subsidiaries, in each case free and clear of all liens, encumbrances and defects except such as are described in the Registration Statement, Statutory Prospectus and the Prospectus or such as do not materially affect the value of such property and do not 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 interfere with the use made and proposed to be made of such property and buildings by the Company and its subsidiaries.

          1.23 Intellectual Property Rights . The Company and its subsidiaries own or possess, or can acquire on commercially reasonable terms, legally enforceable rights to use all trademarks, service marks, trade names, domain names, copyrights, patents, patent rights, inventions, know-how (including trade secrets and other unpatented and/or unpatentable proprietary or confidential information, systems or procedures), and other intellectual property rights (collectively, the “ Intellectual Property ”) as are necessary for the conduct of its or their respective businesses as described in the Registration Statement, the Statutory Prospectus and the Prospectus, except where failure to own, possess or acquire such rights would not result in a Material Adverse Effect. Except as described in the Registration Statement, Statutory Prospectus and the Prospectus, (i) to the knowledge of the Company, there is no infringement, misappropriation or violation by third parties of any such Intellectual Property; (ii) there is no pending or, to the knowledge of the Company, threatened action, suit, proceeding or claim by others challenging the Company’s or any of its subsidiaries’ rights in or to any such Intellectual Property; (iii) the Intellectual Property owned by the Company and its subsidiaries and to the knowledge of the Company, the Intellectual Property licensed to the Company and its subsidiaries has not been adjudged invalid or unenforceable, in whole or in part, and there is no pending or threatened action,

suit, proceeding or claim by others challenging the validity or scope of any such Intellectual Property; (iv) there is no pending or, to the knowledge of the Company, threatened action, suit, proceeding or claim by others against the Company or any of its subsidiaries that the Company or any of its subsidiaries infringes, misappropriates or otherwise violates any Intellectual Property or other proprietary rights of others, and neither the Company nor any of its subsidiaries has received any written notice of such claim; and (v) to the Company’s knowledge, no employee of the Company or any of its subsidiaries is the subject of any claim or proceeding involving a violation of any term of any employment contract, patent disclosure agreement, invention assignment agreement, non-competition agreement, non-solicitation agreement, nondisclosure agreement or any restrictive covenant to or with a former employer where the basis of such violation relates to such employee’s employment with the Company or any of the Company’s subsidiaries or actions undertaken by the employee while employed with the Company or any of the Company’s subsidiaries, except, in each case, for any instances which would not, individually or in the aggregate, result in a Material Adverse Effect.

          1.24 No Labor Disputes . No material labor dispute with the employees of the Company or any of its subsidiaries exists, or, to the knowledge of the Company, is imminent; and the Company is not aware of any existing, threatened or imminent labor disturbance by the employees of any of its principal suppliers, manufacturers or contractors that could have a Material Adverse Effect.

          1.25 Insurance . The Company and its subsidiaries are insured by the insurers of recognized financial responsibility against such losses and risks and in such amounts as are prudent and customary in the businesses in which they are engaged; 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.

          1.26 No Price Stabilization or Manipulation . The Company has not taken, directly or indirectly, any action designed to or that could reasonably be expected to cause or result in any stabilization or manipulation of the price of the Shares.

          1.27 Governmental Permits . 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 business, except where the failure to possess such certificate, authorization or permit would not, individually or in the aggregate, have a Material Adverse Effect. Neither the Company nor any of its subsidiaries has received any notice of proceedings relating to the revocation or modification of any such certificate, authorization or permit which, individually or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would result in a Material Adverse Effect.

          1.28 Financial Statements . The financial statements of the Company and its subsidiaries and the financial statements of Gnossos Software, Inc. included in the Registration Statement, the Statutory Prospectus and the Prospectus, together with related schedules and notes, comply as to form in all material respects with the requirements of Regulation S-X under the Securities Act and present fairly in all material respects the financial position of the Company and the Company’s consolidated subsidiaries at the dates indicated and the statement of operations, stockholders’ equity and cash flows of the Company and the Company’s consolidated subsidiaries for the periods specified; and such financial statements and related schedules and notes thereto, and the unaudited financial information filed with the Commission as part of the Registration Statement, the Statutory Prospectus and the Prospectus, have been prepared in conformity with generally accepted accounting principles, consistently applied throughout the periods involved. The summary and selected financial data included in the Registration Statement, the Statutory Prospectus and the Prospectus

present fairly in all material respects the information shown therein as at the respective dates and for the respective periods specified and have been presented on a basis consistent with the consolidated financial statements set forth in the Registration Statement, the Statutory Prospectus and the Prospectus and other financial information.

          1.29 Contributions, Gifts and Other Payments . Neither the Company, its subsidiaries, nor any other person associated with or acting on behalf of the Company or its subsidiaries, including without limitation any director, officer, agent or employee of the Company or its subsidiaries has, directly or indirectly, while acting on behalf of the Company or its subsidiaries (i) used any corporate funds for unlawful contributions, gifts, entertainment or other unlawful expenses relating to political activity, (ii) made any unlawful payment to foreign or domestic government officials or employees or to foreign or domestic political parties or campaigns from corporate funds, (iii) violated any provision of the Foreign Corrupt Practices Act of 1977, as amended or (iv) made any other unlawful payment.

          1.30 Audit Committee . The Company’s board of directors has validly appointed an audit committee whose composition satisfies the requirements of the Exchange Act, the rules and regulations of the Commission adopted thereunder and Rules 4200 and 4350 of the rules of the National Association of Securities Dealers (the “ NASD ”). The Company’s audit committee has adopted a charter that satisfies the Exchange Act, the rules and regulations of the Commission adopted thereunder and Rules 4200 and 4350 of the NASD Rules.

          1.31 Controls and Procedures . The Company and each of 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. Management of the Company is currently designing, refining and documenting disclosure controls and procedures (as defined in Exchange Act Rules 13a-15 and 15d-15) for the Company that are being designed to ensure that (i) information required to be disclosed by the Company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported, within the time periods specified in the Commission’s rules and forms and (ii) information required to be disclosed by the Company in the reports that it files or submits under the Exchange Act is accumulated and communicated to the Company’s management, including its principal executive and principal financial officers, or persons performing similar functions, as appropriate to allow timely decisions regarding required disclosure. It is the Company’s management’s intention to become fully compliant in all respects with all applicable laws, and related rules and regulations of the Commission, regarding disclosure controls and procedures on or before the date on which such laws, rules or regulations become applicable to the Company

          1.32 Sarbanes-Oxley Act . The Company is in compliance with all currently effective provisions of the Sarbanes-Oxley Act of 2002 and the rules and regulations promulgated thereunder (the “ Sarbanes-Oxley Act ”) that are applicable, or will be applicable as of the date of payment for and delivery of the Firm Shares pursuant hereto, to the Company.

          1.33 Auditor Independence . Ernst & Young LLP, which has expressed its opinion with respect to the financial statements and schedules filed as a part of the Registration Statement and included in the Registration Statement, the Statutory Prospectus and the Prospectus, is and, during the periods covered by

their reports, was an independent public accounting firm within the meaning of Article 2-01 of Regulation S-X under the Securities Act and the rules and regulations promulgated thereunder, to the knowledge of the Company, such accountants are not in violation of the auditor independence requirements of the Sarbanes-Oxley Act, and the rules and regulations promulgated thereunder, set forth in Section 10A of the Exchange Act.

          1.34 Taxes . Each of the Company and its subsidiaries has filed all federal, state, local and foreign tax returns and tax forms required to be filed, except where the failure to file would not have a Material Adverse Effect. Such returns and forms are complete and correct in all material respects. All payroll withholdings required to be made by the Company and its subsidiaries with respect to employees have been made. There have been no tax deficiencies asserted or, to the knowledge of the Company, threatened against the Company or its subsidiaries that could, individually or in the aggregate, result in a Material Adverse Effect.

          1.35 Brokers Fees . There are no contracts, agreements or understandings between the Company and any person that would give rise to a valid claim against the Company or any of the Underwriters for a brokerage commission, finder’s fee or other like payment in connection with the transactions contemplated herein, the Registration Statement, the Disclosure Package and the Prospectus or in any contracts, agreements, understandings, payments, arrangements or issuances with respect to the Company or any of its officers, directors, stockholders, employees or affiliates that may affect the Underwriters’ compensation as determined by the NASD.

          1.36 Directed Share Program . The Company represents and warrants to Thomas Weisel Partners LLC that (i) the Registration Statement, the Prospectus, the Disclosure Package and any Preliminary Prospectus comply, and any further amendments or supplements thereto will comply, with any applicable laws or regulations of foreign jurisdictions in which the Prospectus, the Disclosure Package or any Preliminary Prospectus, as amended or supplemented, if applicable, are distributed in connection with the Directed Share Program, (ii) no authorization, approval, consent, license, order, registration or qualification of or with any government, governmental instrumentality or court, other than such as have been obtained, is necessary under the securities laws and regulations of foreign jurisdictions in which the Directed Shares are offered outside the United States and (iii) neither the Company nor any other person associated with or acting on behalf of the Company, including without limitation any director, officer, agent or employee of the Company, has offered or caused the Underwriters to offer any of the Shares to any person pursuant to the Directed Share Program with the specific intent to unlawfully influence a customer or supplier of the Company to alter the customer’s or supplier’s level or type of business with the Company or a trade journalist or publication to write or public favorable information about the Company or its products.

          1.37 Books and Records . The minute books of the Company and each of its subsidiaries have been made available to the Underwriters and counsel for the Underwriters, and such books (i) contain a complete summary of all meetings and actions of the board of directors or comparable body (including each committee thereof) of the Company and each of its subsidiaries since the time of its respective incorporation or formation through the date of the latest meeting and action and (ii) accurately reflect all transactions referred to in such minutes.

          1.38 Company Not Ineligible Issuer . (i) At the time of filing the Registration Statement and (ii) as of the date of the execution and delivery of this Agreement (with such date being used as the determination date for purposes of this clause (ii)), the Company was not and is not an Ineligible Issuer (as defined in Rule 405 of the Securities Act).

          1.39 Permitted Free Writing Prospectuses . The Company has not made, and will not make, without the prior written consent of the Representatives, any offer relating to the Shares that would constitute an Issuer Free Writing Prospectus or that would otherwise constitute a “free writing prospectus” (as defined in Rule 405 of the Securities Act) required to be filed by the Company with the Commission or retained by the Company under Rule 433 of the Securities Act; provided that the prior written consent of the Representatives hereto shall be deemed to have been given in respect of the Issuer Free Writing Prospectuses included in Schedule C hereto. Any such free writing prospectus consented to by the Representatives is hereinafter referred to as a “Permitted Free Writing Prospectus”. The Company agrees that (i) it has treated and will treat, as the case may be, each Permitted Free Writing Prospectus as an Issuer Free Writing Prospectus, and (ii) has complied and will comply, as the case may be, with the requirements of Rules 164 and 433 of the Securities Act applicable to any Permitted Free Writing Prospectus, including in respect of timely filing with the Commission, legending and record keeping.

          1.40 No Issuer Free Writing Prospectuses . Except as set forth in Schedule C hereto, the Company has not prepared or had prepared, and will not prepare, any Issuer Free Writing Prospectus, and has not distributed and will not distribute any written materials in connection with the offer or sale of the Shares.

     2.  Representations and Warranties of the Selling Stockholders .

          (A). Each of the Selling Stockholders represents and warrants to and agrees with each of the Underwriters that:

          2.1 Due Authorization . This Agreement has been duly authorized, executed and delivered by or on behalf of such Selling Stockholder and is a valid and binding agreement of such Selling Stockholder, enforceable in accordance with its terms, except as rights to indemnification hereunder may be limited by applicable law and except as the enforcement hereof may be limited by bankruptcy, insolvency, reorganization, moratorium or other similar laws relating to or affecting the rights and remedies of creditors or by general equitable principles.

          2.2 Selling Stockholder Documents . The Custody Agreement and the Power of Attorney have been duly authorized, executed and delivered by such Selling Stockholder and are valid and binding agreements of such Selling Stockholder enforceable in accordance with their respective terms, except as rights to indemnification thereunder may be limited by applicable law and except as the enforcement thereof may be limited by bankruptcy, insolvency, reorganization, moratorium or other similar laws relating to or affecting the rights and remedies of creditors or by general equitable principles.

          2.3 No Conflict . The execution and delivery by such Selling Stockholder of, and the performance by such Selling Stockholder of its obligations under, this Agreement, the Custody Agreement signed by such Selling Stockholder and Wachovia Bank, National Association, as Custodian, relating to the deposit of the Shares to be sold by such Selling Stockholder (the “ Custody Agreement ”) and the Power of Attorney appointing certain individuals as such Selling Stockholder’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 applicable law, or the certificate of incorporation or bylaws of such Selling Stockholder or any equivalent constituent documents (if such Selling Stockholder is a corporation, company, partnership or other entity), or any agreement or other instrument binding upon such Selling Stockholder or any judgment, order or decree of any governmental body, agency or court having jurisdiction over such Selling Stockholder, and no consent, approval, authorization or order of, or qualification with, any governmental body or agency is required for the performance by such Selling

Stockholder of its obligations under this Agreement or the Custody Agreement or Power of Attorney of such Selling Stockholder, except 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.

          2.4 Validly Issued Shares . The Shares to be sold by such Selling Stockholder pursuant to this Agreement have been duly authorized and are validly issued, fully paid and non-assessable.

          2.5 Good Title to Shares . Such Selling Stockholder has, and on the Option Closing Date will have, valid title to the Shares to be sold by such Selling Stockholder 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 Stockholder.

          2.6 Delivery of Common Shares . Delivery of the Shares to be sold by such Selling Stockholder pursuant to this Agreement will pass title to such Shares free and clear of any security interests, claims, liens, equities and other encumbrances.

          2.7 No Registration Rights . Such Selling Stockholder does not have any registration or other similar rights to have any equity or debt securities registered for sale by the Company under the Registration Statement or included in the offering contemplated by this Agreement, other than as described in the Registration Statement, Statutory Prospectus and the Prospectus and as have been waived in writing in connection with the offering contemplated hereby.

          2.8 No Price Stabilization or Manipulation . Such Selling Stockholder has not taken and will not take, directly or indirectly, any action designed to or that might be reasonably expected to cause or result in stabilization or manipulation of the price of the Common Stock to facilitate the sale or resale of the Shares.

          2.9 No Free Writing Prospectuses . Such Selling Stockholder has not prepared or had prepared on its behalf or used or referred to, and will not prepare or have prepared on its behalf or use or refer to, any free writing prospectus defined in Rule 405 of the Securities Act and required to be filed by the Company with the Commission or retained by the Company under Rule 433 of the Securities Act (the “ Selling Stockholder Free Writing Prospectus ”), and has not distributed and will not distribute any written materials in connection with the offer or sale of the Shares.

          2.10 Disclosure Made by Selling Stockholders . All information furnished by or on behalf of such Selling Stockholder in writing expressly for use in the Registration Statement, the Disclosure Package, the Prospectus or any Selling Stockholder Free Writing Prospectus or any amendment or supplement thereto used by the Company or any Underwriter, as the case may be, was, as of the Initial Sale Time and on the Closing Date, and on Option Closing Date will be, true, correct and complete in all material respects, and did not as of the Initial Sale Time, and on the Closing Date and the Option Closing Date will not, contain any untrue statement of a material fact or omit to state any material fact required to be made or necessary to make such information not misleading.

          (B). Each of the Selling Stockholders listed on Schedule E hereto (the “ Investor Selling Stockholders ”) represents and warrants to the best of its knowledge with each of the Underwriters that (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, and (ii) the Statutory Prospectus and the Prospectus do 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 Statutory Prospectus or the Prospectus based upon information relating to any Underwriter set forth in the section of the Registration Statement, the Statutory Prospectus or the Prospectus captioned “Underwriting” that was furnished to the Company in writing by such Underwriter through you expressly for use therein.

     3.  Purchase and Sale Agreements

          3.1 Firm Shares . The Company 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 to purchase from the Company at $8.37 per Share (the “ Purchase Price ”) the number of Firm Shares (subject to such adjustments to eliminate fractional shares as you may determine) set forth in Schedule A hereto opposite the name of such Underwriter.

          3.2 Additional Shares . On the basis of the representations and warranties contained in this Agreement, and subject to its terms and conditions, the Selling Stockholders agree to sell to the Underwriters the Additional Shares, and the Underwriters shall have a one-time right to purchase, severally and not jointly, up to 750,000 Additional Shares at the Purchase Price. If you, on behalf of the Underwriters, elect to exercise such option, you shall so notify the Company and Richard Rudman, as the Attorney-In-Fact for the Selling Stockholders, in writing not later than thirty (30) days after the date of this Agreement, which 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. Such date may be the same as the Closing Date (as defined below) but not earlier than the Closing Date nor later than ten (10) business days after the date of such notice. Additional Shares may be purchased as provided in Section 4 hereof solely for the purpose of covering over- allotments made in connection with the offering of the Firm Shares. If any Additional Shares are to be purchased, 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 as the number of Firm Shares set forth in Schedule A hereto opposite the name of such Underwriter bears to the total number of Firm Shares.

          3.3 Market Standoff Provision . Each Seller hereby agrees that, without the prior written consent of Thomas Weisel Partners LLC, it will not, during the period ending 180 days after the date of the Prospectus (the “ Restricted Period ”), (i) 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 (ii) 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 (i) or (ii) 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) the Shares to be sold hereunder, (B) the issuance by the Company of shares of Common Stock upon the exercise of options or warrants or the conversion of a security outstanding on the date hereof and which is described in the Registration Statement and Prospectus, (C) transactions by any person other than the Company relating to shares of Common Stock or other securities acquired in open market transactions after the completion of the offering of the Shares, (D) the grant of options or the issuance of shares of Common Stock under the Company’s stock option plans, (E) the filing of any registration statement on Form S-8 in respect of any employee benefit plan described in the Registration Statement, the Statutory Prospectus and Prospectus, and (F) the issuance by the Company of shares of Common Stock having a value of up to

$10,000,000 pursuant to an acquisition or merger transaction. In addition, each Selling Stockholder agrees that, without the prior written consent of Thomas Weisel Partners LLC, it will not, during the Restricted Period, 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 Com