SONIC SOLUTIONS 920,000 Shares Common Stock (no par value)

Exhibit 10.1

SONIC SOLUTIONS

920,000 Shares

Common Stock

(no par value)

Underwriting Agreement

September 17, 2003

Adams, Harkness & Hill, Inc.

60 State Street

Boston, Massachusetts 02109

Ladies and Gentlemen:

Sonic Solutions, a California corporation (the “Company”), proposes, subject to the terms and conditions stated herein, to issue and sell to you (the “Underwriters”) an aggregate of 920,000 shares (the “Shares”) of common stock of the Company, no par value (“Common Stock”).

1. Representations and Warranties of the Company. The Company represents and warrants to, and agrees with, each of the Underwriters that as of the date hereof, and as of the Time of Delivery (as hereinafter defined):

(a) The Company has filed with the Securities and Exchange Commission (the “Commission”) a registration statement on Form S-3 (No. 333-103624), for the registration of the Shares and certain other securities described therein under the Securities Act of 1933, as amended (the “Act”), and the offering thereof from time to time in accordance with Rule 415 of the rules and regulations of the Commission under the Act (the “Act Regulations”). Such registration statement has been declared effective by the Commission. Such registration statement, in the form in which it became effective, is referred to herein as the “Registration Statement”; and the final prospectus and the final prospectus supplement relating to the offering of the Shares, in the form first furnished to the Underwriters by the Company for use in connection with the offering of the Shares, are collectively referred to herein as the “Prospectus”; provided, however, that all references to the “Registration Statement” and the “Prospectus” shall also be deemed to include all documents incorporated therein by reference pursuant to the Securities Exchange Act of 1934, as amended (the “Exchange Act”), prior to the time the applicable final prospectus and the final prospectus supplement were first furnished to the Underwriters by the Company; provided, further, that if the Company files a registration statement with the Commission pursuant to Rule 462(b) of the Act Regulations (the “Rule 462(b) Registration Statement”), then, after such filing, all references to “Registration Statement” shall also be deemed to include the Rule 462(b) Registration Statement. For purposes of this Agreement, all references to the Registration Statement, Prospectus or to any amendment or supplement to any of the foregoing shall be deemed to include any copy filed with the Commission pursuant to its Electronic Data Gathering, Analysis and Retrieval system (“EDGAR”).

(b) No order preventing or suspending the effectiveness of the Registration Statement, any post-effective amendment thereto, or the Rule 462(b) Registration Statement, if any, has been issued and no proceeding for that purpose has been initiated or, to the Company’s knowledge, threatened by the Commission.

(c) The Company has timely filed all reports required of it under the Exchange Act and the Company meets the requirements for use of Form S-3 under the Act;

(d) The documents incorporated by reference in the Prospectus, when they were filed with the Commission, conformed in all material respects to the requirements of the Exchange Act, and the rules and regulations of the Commission thereunder, and none of such documents contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading;

(e) The Registration Statement conforms, and the Prospectus and any further amendments or supplements to the Registration Statement or the Prospectus will conform, in all material respects to the requirements of the Act and the Act Regulations and do not and will not, as of the applicable effective date as to the Registration Statement and any amendment thereto and as of the applicable filing date and the applicable Time of Delivery as to the Prospectus and any amendment or supplement thereto contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or, in the case of the Registration Statement or any amendment thereto, necessary to make the statements therein not misleading and, in the case of the Prospectus or any supplement thereto, necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided, however, that this representation and warranty shall not apply to any statements or omissions made in reliance upon and in conformity with information furnished in writing to the Company by an Underwriter through you expressly for use therein;

(f) There are no contracts or other documents required to be described in the Registration Statement or to be filed as exhibits to the Registration Statement by the Act or by the Act Regulations which have not been described or filed or incorporated by reference in the Registration Statement, as required; the contracts so described in the Prospectus to which the Company or any of its subsidiaries is a party have been duly authorized, executed and delivered by the Company or its subsidiaries, constitute valid and binding agreements of the Company or its subsidiaries and are enforceable against and by the Company or its subsidiaries, as applicable, in accordance with their respective terms, except as such enforceability may be limited by (i) applicable bankruptcy, insolvency, moratorium, reorganization, fraudulent conveyance or similar laws in effect which affect the enforcement of creditors’ rights generally, (ii) general principles of equity, whether considered in a proceeding at law or in equity and (iii) state or federal securities laws or policies relating to the non-enforceability of the indemnification provisions contained therein, and are in full force and effect on the date hereof; and neither the Company nor, to the Company’s knowledge, any other party thereto, is in breach of or default under any of such contracts, except for such breaches or defaults that will not result in a material adverse change in the business, assets, management, financial position or results of operations of the Company (hereinafter, a “Material Adverse Change”);

(g) Except as stated in the Prospectus, neither the Company nor any of its subsidiaries has since the date of the latest audited financial statements included or incorporated by reference in the Prospectus (i) sustained any loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, that is in each case material to the Company and its subsidiaries taken as a whole, otherwise than as set forth or contemplated in the Prospectus; (ii) had any change in the capital stock (other than issuances of Common Stock pursuant to Company stock option plans described in the Registration Statement and Prospectus); (iii) entered into any material contracts; or (iv) sustained any Material Adverse Change, or any development that is reasonably likely to result in a Material Adverse Change, otherwise than as set forth or contemplated in the Prospectus;

(h) Neither the Company nor any subsidiary owns any real property. The Company and its subsidiaries have good and marketable title to all personal property and assets described in the Prospectus as owned by it and which are material to the business of the Company, in each case free and clear of all liens, charges, encumbrances or restrictions, except such as (i) are described in the Prospectus or (ii) would not, singly or in the aggregate, result in a Material Adverse Change; 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 would not, singly or in the aggregate, result in a Material Adverse Change and do not interfere with the use made and proposed to be made of such property and buildings by the Company and its subsidiaries; the Company and its subsidiaries own or lease all such properties as are necessary to its operations as now conducted or as proposed to be conducted, except where the failure to so own or lease would not result in a Material Adverse Change;

(i) Each of the Company and its subsidiaries has been duly incorporated and is validly existing as a corporation in good standing under the laws of its respective jurisdiction of incorporation, each with full corporate power and authority to own its properties and conduct its business as described in the Prospectus, and each has been duly qualified as a foreign corporation for the transaction of business and is in good standing under the laws of each other jurisdiction in which it owns or leases properties or conducts any business so as to require such qualification, except where failure to be so qualified or in good standing would result in a Material Adverse Change;

(j) The Company has an authorized capitalization as set forth in the Prospectus (other than for issuances after the dates thereof, if any, pursuant to employee benefit plans described in any Prospectus or upon exercise of outstanding options or warrants described in any Prospectus), and all the issued shares of capital stock of the Company, in all material respects, (i) have been duly and validly authorized and issued, (ii) are fully paid and non-assessable and (iii) conform to the description of the Common Stock contained or incorporated by reference in the Prospectus; all of the issued shares of capital stock of each subsidiary of the Company (i) have been duly and validly authorized and issued, are fully paid and non-assessable and (ii) except as disclosed in the Prospectus, are owned directly by the Company, free and clear of all liens, encumbrances, equities or claims; except as disclosed in or contemplated by the Prospectus and the consolidated financial statements of the Company, and the related notes thereto, included in the Prospectus, neither the Company nor any subsidiary has outstanding any options to purchase, or any preemptive rights or other rights to subscribe for or to purchase any securities or obligations convertible into, or any contracts or commitments to issue or sell, shares of its capital stock or any such options, rights, convertible securities or obligations (other than stock and options granted pursuant to the Company’s stock option plans in the ordinary course of business consistent with past practice); and the description of the Company’s stock option plans and the options or other rights granted and exercised thereunder set forth in the Prospectus accurately and fairly presents in all material respects the information required to be shown with respect to such plans, options and rights;

(k) The unissued Shares to be issued and sold by the Company to the Underwriters hereunder have been duly and validly authorized and, when issued and delivered against payment therefor as provided herein, will be duly and validly issued and fully paid and non-assessable and will conform to the description of the Common Stock contained or incorporated by reference in the Prospectus; no preemptive rights or other rights to subscribe for or purchase exist with respect to the issuance and sale of the Shares by the Company pursuant to this Agreement; no stockholder of the Company has any right, which has not been waived, to require the Company to register the sale of any shares of capital stock owned by such stockholder under the Act in the public offering contemplated by this Agreement; and no further approval or authority of the stockholders or the Board of Directors of the Company will be required for the issuance and sale of the Shares to be sold by the Company as contemplated herein;

(l) The Company has full corporate power and authority to enter into this Agreement; and this Agreement has been duly authorized, executed and delivered by the Company, constitutes a valid and binding obligation of the Company and is enforceable against the Company in accordance with its terms, except as such enforceability may be limited by (i) applicable bankruptcy, insolvency, moratorium, reorganization, fraudulent conveyance or similar laws in effect which affect the enforcement of creditors’ rights generally, (ii) general principles of equity, whether considered in a proceeding at law or in equity and (iii) state or federal securities laws or policies relating to the non-enforceability of the indemnification provisions contained herein;

(m) The issue and sale of the Shares by the Company and the compliance by the Company with all of the provisions of this Agreement and the consummation of the transactions herein contemplated will not conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default under, any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which the Company or any of its subsidiaries is a party or by which the Company or any of its subsidiaries is bound or to which any of the property or assets of the Company or any of its subsidiaries is subject, except such breaches or violations that would not result in a Material Adverse Change, nor will such action result in any violation of the provisions of the Certificate of Incorporation or By-laws of the Company, as currently in effect, or any statute or any order, rule or regulation of any court or governmental agency or body having jurisdiction over the Company or any of its subsidiaries or any of their properties; and no consent, approval, authorization, order, registration or qualification of or with any such court or governmental agency or body is required for the issue and sale of the Shares or the consummation by the Company of the transactions contemplated by this Agreement, except the registration under the Act of the Shares and such consents, approvals, authorizations, registrations or qualifications as may be required under state securities or Blue Sky laws or the bylaws and rules of the National Association of Securities Dealers, Inc. (“NASD”) in connection with the purchase and distribution of the Shares by the Underwriters;

(n) There are no legal or governmental actions, suits or proceedings pending or, to the best of the Company’s knowledge, threatened to which the Company or any of its subsidiaries is or may be a party or of which property owned or leased by the Company or any of its subsidiaries is or may be the subject, which actions, suits or proceedings, would reasonably be expected, individually or in the aggregate, to prevent or adversely affect the transactions contemplated by this Agreement or result in a Material Adverse Change; no labor disturbance by the employees of the Company or any of its subsidiaries exists or, to the knowledge of the Company, is imminent that would reasonably be expected to result in a Material Adverse Change; and neither the Company nor any of its subsidiaries is a party or subject to the provisions of any injunction, judgment, decree or order of any court, regulatory body, administrative agency or other governmental body, that would reasonably be expected to result in a Material Adverse Change;

(o) To the best knowledge of the Company, the Company and its subsidiaries possess all licenses, certificates, authorizations or permits issued by the appropriate governmental or regulatory agencies or authorities that are necessary to enable them to own, lease and operate their respective properties and to carry on their respective businesses as presently conducted except, where the failure to possess such licenses, certificates, authorization or permits would not reasonably be expected to result in a Material Adverse Change, and neither the Company nor any of its subsidiaries has received any notice of proceedings relating to the revocation or modification of any such license, certificate, authority or permit which, singly or in the aggregate, would reasonably be expected to result in a Material Adverse Change;

(p) The Company and its subsidiaries (i) are in compliance in all material respects with any and all applicable foreign, federal, state and local laws and regulations relating to the protection

of human health and safety, including, without limitation, those relating to occupational safety and health, the environment or hazardous or toxic substances or wastes, pollutants or contaminants, including, without limitation, those relating to the storage, handling or transportation of hazardous or toxic materials (collectively, “Environmental Laws”) and (ii) 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, reasonably be expected to result in a Material Adverse Change. The Company, in its reasonable judgment, has concluded that any 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) would not, singly or in the aggregate, reasonably be expected to result in a Material Adverse Change;

(q) KPMG LLP, who has audited certain financial statements of the Company, are independent certified public accountants as required by the Act and the Act Regulations;

(r) The consolidated financial statements and schedules of the Company, and the related notes thereto, included or incorporated by reference in the Registration Statement and the Prospectus present fairly in all material respects the financial position of the Company as of the respective dates of such financial statements and schedules, and the results of operations and cash flows of the Company for the respective periods covered thereby, subject to the normal year-end adjustments which are not expected to be material in amount; such statements, schedules and related notes have been prepared in accordance with generally accepted accounting principles in the United States of America, as applicable, applied on a consistent basis, except as may be expressly stated in the related notes thereto, as certified by the independent public accountants named in paragraph (q) above; no other financial statements or schedules are required to be included in the Registration Statement by the Act and the Act Regulations; and the selected financial data set forth in the Prospectus under the captions “Capitalization” and “Selected Consolidated Financial Information” fairly present in all material respects the information set forth therein on the basis stated in the Registration Statement;

(s) Except as disclosed in the Registration Statement and Prospectus, (i) the Company owns, possesses or has the right to use all trademarks, service marks, trade names, patent rights, copyrights, licenses, trade secrets and proprietary rights necessary to conduct its business as now conducted, (ii) the Company has not received notice of any infringement by the Company of any trademark, service mark, trade name, patent, copyright, license, trade secret, proprietary or other similar rights of others, and (iii) to the Company’s knowledge, there is no claim of infringement being made against the Company regarding any trademark, service mark, trade name, patent, copyright, license, trade secret, proprietary or other similar rights which if adversely decided, would reasonably be expected to result in a Material Adverse Change. Except as disclosed in the Registration Statement and Prospectus, (w) none of the technology employed by the Company has been obtained or is being used by the Company in violation of any contractual obligation binding on the Company or, to the Company’s knowledge, any of its officers, directors, employees or consultants or otherwise in violation of the rights of any person, except for such violations that would not reasonably be expected to result in a Material Adverse Change; (x) the Company has not received, and to the Company’s knowledge, none of its employees has received, any written or oral communications alleging that the Company has violated or, by conducting its business as proposed, would violate any of the intellectual property or proprietary rights of any other person or entity; (y) the operation of the business of the Company as currently operated will not, to the Company’s knowledge, result in a material breach or violation of the terms, conditions or provisions of, or constitute a default under, any material contract, covenant or instrument under which any of such employees is now obligated; and (z) the Company has taken reasonable measures to prevent the

unauthorized dissemination or publication of its confidential information or the confidential information of third parties in its possession. Each current employee of the Company who in the course of their duties has possession of material confidential or proprietary information of the Company, has executed an agreement with the Company regarding confidential information and the assignment of proprietary information to the Company;

(t) The Company and each of its subsidiaries have filed all necessary federal, state and foreign income and franchise tax returns, except to the extent that the failure to file such tax returns would not have a Material Adverse Change, each of which has been true and correct in all material respects, and have paid all taxes shown as due thereon; and the Company has no knowledge of any tax deficiency which has been or might reasonably be asserted or threatened against the Company or any of its subsidiaries which could reasonably be expected to result in a Material Adverse Change;

(u) The Company is not an “investment company” or an “affiliated person” of, or “promoter” or “principal underwriter” for, an “investment company”, as such terms are defined in the Investment Company Act of 1940, as amended (the “Investment Company Act”);

(v) Each of the Company and its subsidiaries maintains insurance of the types and in the amounts which it deems adequate for its business, including, but not limited to, insurance covering real and personal property owned or leased by the Company and its subsidiaries against theft, damage, destruction, acts of vandalism and all other risks customarily insured against, all of which insurance is in full force and effect;

(w) To the best knowledge of the Company, neither the Company nor any of its subsidiaries has at any time during the last five years (i) made any unlawful contribution to any candidate for foreign office, or failed to disclose fully any contribution in violation of law, or (ii) made any payment to any foreign, federal or state governmental officer or official, or other person charged with similar public or quasi-public duties, other than payments required or permitted by the laws of the United States or any jurisdiction thereof;

(x) Other than exempted activity under Regulation M, the Company has not taken and will not take, directly or indirectly through any of its directors, officers or controlling persons, any action which is designed to or which has constituted or which might reasonably be expected to cause or result in stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Shares;

(y) The Common Stock of the Company has been registered pursuant to Section 12(g) of the Exchange Act and the Company is not required to take any further action for the inclusion of the Shares on the Nasdaq National Market; and

(z) Each of the Company and the subsidiaries (i) makes and keeps accurate books and records and (ii) maintains a system of accounting controls sufficient to provide reasonable assurances that: (A) transactions are executed in accordance with management’s general or specific authorization; (B) transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principals in the United States of America, the Act and the Exchange Act; (C) access to assets is permitted only in accordance with management’s general or specific authorization; and (D) the recorded accountability for assets is compared with existing assets at reasonable intervals and appropriate action is taken with respect to any differences.

2. Shares Subject to Sale. On the basis of the representations, warranties and agreements of the Company contained herein, and subject to the terms and conditions of this Agreement, (i) the

Company agrees to issue and sell the Shares to the several Underwriters and (ii) each of the Underwriters agrees, severally and not jointly, to purchase from the Company, at a purchase price per share of $14.25, the respective number of Shares set forth opposite the name of such Underwriter in Schedule I hereto.

3. Offering. Upon the authorization by you of the release of the Shares, the several Underwriters propose to offer the Shares for sale upon the terms and conditions set forth in the Prospectus.

4. Closing. Certificates in definitive form for the Shares to be purchased by each Underwriter hereunder, and in such denominations and registered in such names as Adams, Harkness & Hill, Inc. may request upon at least forty-eight hours’ prior notice to the Company, shall be delivered by or on behalf of the Company to you for the account of such Underwriter, against payment by such Underwriter or on its behalf of the purchase price therefor by wire transfer of same day federal funds, all at the office of Adams, Harkness & Hill, Inc., 60 State Street, Boston, Massachusetts 02109. The time and date of such delivery and payment shall be, with respect to the Firm Shares, 9:30 a.m., Boston time, on September 22, 2003 or such other time and date as you and the Company may agree upon in writing. Such time and date for delivery of the Shares is herein called the “Time of Delivery.” Such certificates will be made available for checking and packaging at least twenty-four hours prior to the Time of Delivery at such location as you may specify. If the Underwriters so elect, delivery of the Shares may be made by credit through full fast transfer to the accounts at the Depository Trust Company designated by Adams, Harkness & Hill, Inc.

5. Covenants of the Company. The Company hereby covenants to the Underwriters as follows:

(a) To prepare the Prospectus in a form approved by you and to file such Prospectus pursuant to Rule 424(b) under the Act not later than Commission’s close of business on the second business day following the execution and delivery of this Agreement, and to make no further amendment or any supplement to the Registration Statement or Prospectus which shall be reasonably disapproved by you promptly giving reasonable notice thereof; to advise you, promptly after it receives notice thereof, of the time when the Registration Statement, or any amendment thereto, has been filed or becomes effective or any supplement to the Prospectus or any amended Prospectus has been filed and to furnish you copies thereof; to advise you, promptly after it receives notice thereof, of the issuance by the Commission of any stop order or of any order preventing or suspending the use of any preliminary Prospectus or Prospectus, of the suspension of the qualification of the Shares for offering or sale in any jurisdiction, of the initiation or threatening of any proceeding for any such purpose, or of any request by the Commission for the amending or supplementing of the Registration Statement or Prospectus or for additional information; and, in the event of the issuance of any stop order or of any order preventing or suspending the use of any preliminary Prospectus or Prospectus or suspending any such qualification, to use promptly its best efforts to obtain its withdrawal;

(b) Promptly, from time to time, to take such action as you may reasonably request to qualify the Shares for offering and sale under the securities laws of such jurisdictions as you may request and to comply with such laws so as to permit the continuance of sales and dealings therein in such jurisdictions for as long as may be necessary to complete the distribution of the Shares, provided that in connection therewith the Company shall not be required to qualify as a foreign corporation or to file a general consent to service of process in any jurisdiction;

(c) To furnish the Underwriters with copies of the Prospectus in such quantities as you may from time to time reasonably request, and, if the delivery of a prospectus is required at any time prior to the expiration of nine months after the time of issuance of the Prospectus in connection with the

offering or sale of the Shares and if at such time any events shall have occurred as a result of which the Prospectus as then amended or supplemented would, in the judgment of the Company or in the reasonable opinion of the Underwriters or counsel for the Underwriters, include an untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in light of the circumstances under which they were made when such Prospectus is delivered, not misleading, or, if for any other reason it shall be necessary during such same period to amend or supplement the Prospectus in order to comply with the Act, to notify you and upon your request to prepare and furnish without charge to each Underwriter and to any dealer in securities as many copies as you may from time to time reasonably request of an amended Prospectus or a supplement to the Prospectus which will correct such statement or omission or effect such compliance, and in case any Underwriter is required by law to deliver a prospectus in connection with sales of any of the Shares at any time nine months or more after the time of issue of the Prospectus, upon your request but at the expense of such Underwriter, to prepare and deliver to such Underwriter as many copies as you may request of an amended or supplemented Prospectus complying with Section 10(a)(3) of the Act;

(d) To make generally available to its security holders as soon as practicable, but in any event not later than the forty-fifth (45th) day following the end of the full fiscal quarter first occurring after the first anniversary of the effective date of the Registration Statement (as defined in Rule 158(c)), an earnings statement of the Company and its subsidiaries (which need not be audited) complying with Section 11(a) of the Act and the rules and regulations of the Commission thereunder (including, at the option of the Company, Rule 158);

(e) To furnish to its stockholders as soon as practicable after the end of each fiscal year an annual report (including a balance sheet and statements of income, stockholders’ equity and cash flow of the Company and its consolidated subsidiaries certified by independent public accountants) and to make available (within the meaning of Rule 158(b) under the Act) as soon as practicable after the end of each of the first three quarters of each fiscal year (beginning with the fiscal quarter ending after the effective date of the Registration Statement), consolidated summary financial information of the Company and its subsidiaries for such quarter in reasonable detail;

(f) During a period of five years from the effective date of the Registration Statement, to furnish to you upon your request copies of all reports or other communications (financial or other) furnished to stockholders generally, and deliver to you as soon as they are available, copies of any publicly available reports and financial statements furnished to or filed with the Commission, the Nasdaq National Market or any national securities exchange on which any class of securities of the Company is listed (such financial statements to be on a combined or consolidated basis to the extent the accounts of the Company and its subsidiaries are combined or consolidated in reports furnished to its stockholders generally or to the Commission);

(g) To, during the period when the Prospectus is required to be delivered under the Act or the Exchange Act, file all documents required to be filed with the Commission pursuant to the Exchange Act within the time periods required by the Exchange Act and the regulations promulgated thereunder; and

(h) To use the net proceeds acquired by it from the sale of the Shares in the manner specified in the Prospectus under the caption “Use of Proceeds” and in a manner such that the Company will not become an “investment company” as that term is defined in the Investment Company Act.

6. Expenses. The Company covenants and agrees with the several Underwriters that the Company will pay or cause to be paid the following: (i) the fees, disbursements and expenses of the Company’s counsel and accountants in connection with the registration of the Shares under the Act and

all other expenses in connection with the preparation, printing, filing or delivery of the Registration Statement, any preliminary Prospectus and the Prospectus and amendments and supplements thereto and the mailing and delivering of copies thereof to the Underwriters and dealers; (ii) the cost of reproducing and delivering any Agreement among Underwriters, this Agreement, the Blue Sky Memorandum and any other documents in connection with the offering, purchase, sale and delivery of the Shares; (iii) all expenses and filing fees in connection with the qualification of the Shares for offering and sale under state securities laws as provided in Section 5(b) hereof and securing any required review by the NASD of the terms of the sale of the Shares, including the fees and disbursements of counsel for the Underwriters in connection with such qualification and review and in connection with the Blue Sky survey subject to a maximum of $5,000; (iv) the cost of preparing stock certificates; (v) the cost and charges of any transfer agent or registrar; and (vi) all other costs and expenses incident to the performance of its obligations hereunder which are not otherwise specifically provided for in this Section. It is understood, however, that, except as provided in this Section, Section 8 and Section 11 hereof, the Underwriters will pay all of their own costs and expenses, including the fees of their counsel, stock transfer taxes on resale of any of the Shares by them, and any advertising expenses connected with any offers they may make.

7. Conditions of Underwriters’ Obligations. The obligations of the Underwriters hereunder, as to the Shares to be delivered at the Time of Delivery, shall be subject, in their discretion, to the condition that all representations and warranties and other statements of the Company herein are, at and as of such Time of Delivery, true and correct, the condition that the Company shall have performed all of its respective obligations hereunder theretofore to be performed, and the following additional conditions:

(a) The Prospectus shall have been filed with the Commission pursuant to Rule 424(b) within the applicable time period prescribed for such filing by the rules and regulations under the Act and in accordance with Section 5(a) hereof, no stop order suspending the effectiveness of the Registration Statement or any part thereof shall have been issued and no proceeding for that purpose shall have been initiated or threatened by the Commission; and all requests for additional information on the part of the Commission shall have been complied with to your reasonable satisfaction;

(b) Goodwin Procter LLP, counsel to the Underwriters, shall have furnished to you such opinion or opinions, dated such Time of Delivery, with respect to this Agreement, the Registration Statement, the Prospectus, and other related matters as you may reasonably request;

(c) Heller Ehrman White & McAuliffe LLP counsel to the Company, shall have furnished to you their written opinion, dated such Time of Delivery, in form and substance reasonably satisfactory to you, with respect to the matters set forth in Annex I hereto;

(d) On the date hereof and also at the Time of Delivery, KPMG LLP, shall have furnished to you a letter or letters, dated the respective date of delivery thereof, in form and substance reasonably satisfactory to you, to the effect set forth in Annex II hereto;

(e) (i) Neither the Company nor any of its subsidiaries shall have sustained since the date of the latest audited financial statements included or incorporated by reference in the Prospectus any loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, that is in each case material to the Company and its subsidiaries taken as a whole, otherwise than as set forth or contemplated in the Prospectus or as would not result in a Material Adverse Change, and (ii) since the respective dates as of which information is given in the Prospectus, there shall not have been any change in the capital stock (other than issuances of Common Stock pursuant to Company stock option plans described in the Registration Statement and Prospectus) or long-term debt of the Company or any change, or any development that is reasonably likely to result in a Material Adverse Change, otherwise than as set

forth or contemplated in the Prospectus, the effect of which, in any such case described in clause (i) or (ii), is in your good faith judgment so material and adverse as to make it impracticable or inadvisable to proceed with the public offering or the delivery of the Shares being delivered at such Time of Delivery on the terms and in the manner contemplated in the Prospectus;

(f) On or after the date hereof there shall not have occurred any of the following: (i) additional material governmental restrictions, not in force and effect on the date hereof, shall have been imposed upon trading in securities generally or minimum or maximum prices shall have been generally established on the New York Stock Exchange or on the American Stock Exchange or in the over the counter market by the NASD, or trading in securities generally shall have been suspended on either such Exchange or in the over the counter market by the NASD, or a general banking moratorium shall have been established by federal or New York authorities, (ii) an outbreak of major hostilities or other national or international calamity or any substantial change in political, financial or economic conditions shall have occurred or shall have accelerated or escalated to such an extent, as, in the good faith judgment of the Underwriters, to affect materially and adversely the marketability of the Shares, or (iii) there shall be any action, suit or proceeding pending or threatened, or there shall have been any development involving particularly the business or properties or securities of the Company or any of its subsidiaries or the transactions contemplated by this Agreement, which, in the good faith judgment of the Underwriters, has materially and adversely affected the Company’s business or earnings and makes it impracticable or inadvisable to offer or sell the Shares;

(g) The Shares to be sold by the Company at such Time of Delivery shall have been accepted for quotation, subject to notice of issuance, on the Nasdaq National Market System; and

(h) The Company shall have furnished or caused to be furnished to you at such Time of Delivery certificates of officers of the Company, in their capacities as such, satisfactory to you, as to the accuracy of the representations and warranties of the Company, herein at and as of such Time of Delivery, as to the performance by the Company, of all of its obligations hereunder to be performed at or prior to such Time of Delivery, and as to such other matters as you may reasonably request and the Company shall have furnished or caused to be furnished certificates as to the matters set forth in subsections (a) and (e) of this Section, and as to such other matters as you may reasonably request.

8. Indemnification and Contribution.

(a) The Company will indemnify and hold harmless each Underwriter and each person, if any, who controls such Underwriter against any losses, claims, damages or liabilities, joint or several, to which such Underwriter or controlling person may become subject, under the Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon an untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or the Prospectus, or any amendment or supplement thereto, or arise out of or are based upon the omission or alleged omission to state therein a material fact required to be stated therein or, in the case of the Registration Statement or any amendment thereto, necessary to make the statements therein not misleading and, in the case of the Prospectus or any supplement thereto, necessary to make the statements therein, in light of the circumstances in which they were made, not misleading, and will reimburse each Underwriter for any legal or other expenses reasonably incurred by such Underwriter in connection with investigating or defending any such action or claim as such expenses are reasonably incurred; provided, however, that the Company shall not be liable in any such case to the extent that any such loss, claim, damage or liability arises out of or is based upon an untrue statement or alleged untrue statement or omission or alleged omission made in the Registration Statement or the Prospectus or any such amendment or supplement in reliance upon and in conformity with written information furnished to the Company by any Underwriter through you expressly for use therein.

(b) Each Underwriter will indemnify and hold harmless the Company against any losses, claims, damages or liabilities to which the Company may become subject, under the Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon an untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or the Prospectus, or any amendment or supplement thereto, or arise out of or are based upon the omission or alleged omission to state therein a material fact required to be stated therein or, in the case of the Registration Statement or any amendment thereto, necessary to make the statements therein not misleading and, in the case of the Prospectus or any supplement thereto, necessary to make the statements therein, in light of the circumstances in which they were made, not misleading, in each case to the extent, but only to the extent, that such untrue statement or alleged untrue statement or omission or alleged omission was made in the Registration Statement or the Prospectus or any such amendment or supplement in reliance upon and in conformity with written information furnished to the Company by such Underwriter through you expressly for use therein; and will reimburse the Company for any legal or other expenses reasonably incurred by the Company in connection with investigating or defending any such action or claim as such expenses are reasonably incurred.

(c) Promptly after receipt by an indemnified party under subsection (a) or (b) above of notice of the commencement of any action, such indemnified party shall, if a claim in respect thereof is to be made against the indemnifying party under such subsection, notify the indemnifying party in writing of the commencement thereof; but the omission so to notify the indemnifying party shall not relieve it from any liability which it may have to any indemnified party otherwise than under such subsection. In case any such action shall be brought against any indemnified party and it shall notify the indemnifying party of the commencement thereof, the indemnifying party shall be entitled to participate therein and, to the extent that it shall elect, jointly with any other indemnifying party similarly notified, by written notice delivered to the indemnified party promptly after receiving the aforesaid notice from such indemnified party, to assume the defense thereof, with counsel reasonably satisfactory to such indemnified party (who shall not, except with the consent of the indemnified party, be counsel to the indemnifying party), and, after notice from the indemnifying party to such indemnified party of its election so to assume the defense thereof, the indemnifying party shall not be liable to such indemnified party under such subsection for any legal expenses of other counsel or any other expenses, in each case subsequently incurred by such indemnified party, in connection with the defense thereof other than reasonable costs of investigation. No indemnifying party shall, without the prior written consent of the indemnified party, effect the settlement or compromise of, or consent to the entry of any judgment with respect to, any pending or threatened action or claim in respect of which indemnification or contribution may be sought hereunder (whether or not the indemnified party is an actual or potential party to such action or claim) unless such settlement, compromise or judgment (i) includes an unconditional release of the indemnified party from all liability arising out of such action or claim and (ii) does not include a statement as to or an admission of fault, culpability or a failure to act, by or on behalf of any indemnified party. No indemnifying party shall be liable for any settlement of any action or claim effected without its prior written consent, which consent shall not be unreasonably withheld.

(d) If the indemnification provided for in this Section 8 is unavailable to or insufficient to hold harmless an indemnified party under subsection (a) or (b) above in respect of any losses, claims, damages or liabilities (or actions in respect thereof) referred to therein, then each indemnifying party shall contribute to the amount paid or payable by such indemnified party as a result of such losses, claims, damages or liabilities (or actions in respect thereof) in such proportion as is appropriate to reflect the relative benefits received by the Company on the one hand and the Underwriters on the other from the offering of the Shares. If, however, the allocation provided by the immediately preceding sentence is not permitted by applicable law or if the indemnified party failed to give the notice required under subsection (c) above, then each indemnifying party shall contribute to such amount paid or payable by such indemnified party in such proportion as is appropriate to reflect not only such relative

benefits but also the relative fault of the Company on the one hand and the Underwriters on the other in connection with the statements or omissions which resulted in such losses, claims, damages or liabilities (or actions in respect thereof), as well as any other relevant equitable considerations. The relative benefits received by the Company on the one hand and the Underwriters on the other shall be deemed to be in the same proportion as the total net proceeds from the offering (before deducting expenses) received by the Company, bear to the total underwriting discounts and commissions received by the Underwriters, in each case as set forth in the table on the cover page of the Prospectus. The relative fault 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 Company on the one hand or the Underwriters on the other and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission. The Company and the Underwriters agree that it would not be just and equitable if contributions pursuant to this subsection (d) 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 which does not take account of the equitable considerations referred to above in this subsection (d). The amount paid or payable by an indemnified party as a result of the losses, claims, damages or liabilities (or actions in respect thereof) referred to above in this subsection (d) shall be deemed to include 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 subsection (d), 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 which 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 Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The Underwriters’ obligations in this subsection (d) to contribute are several in proportion to their respective underwriting obligations and not joint.

(e) The obligations of the Company under this Section 8 shall be in addition to any liability which the Company may otherwise have and shall extend, upon the same terms and conditions, to each person, if any, who controls any Underwriter within the meaning of the Act; and the obligations of the Underwriter under this Section 8 shall be in addition to any liability which the respective Underwriters may otherwise have and shall extend, upon the same terms and conditions, to each officer and director of the Company and to each person, if any, who controls the Company within the meaning of the Act.

9. Termination.

(a) If any Underwriter shall default in its obligation to purchase the Shares which it has agreed to purchase hereunder at the Time of Delivery, you may in your discretion arrange for you or another party or other parties to purchase such Shares on the terms contained herein. If within thirty-six (36) hours after such default by any Underwriter you do not arrange for the purchase of such Shares, then the Company shall be entitled to a further period of thirty-six (36) hours within which to procure another party or other parties satisfactory to you to purchase such Shares on such terms. In the event that, within the respective prescribed periods, you notify the Company that you have so arranged for the purchase of such Shares, or the Company notifies you that it has so arranged for the purchase of such Shares, you or the Company shall have the right to postpone such Time of Delivery for a period of not more than seven (7) days, in order to effect whatever changes may thereby be made necessary in the Registration Statement or the Prospectus, or in any other documents or arrangements, and the Company agrees to file promptly any amendments to the Registration Statement or the Prospectus which in your opinion may thereby be made necessary. The term “Underwriter” as used in this Agreement shall include any person substituted under this Section with like effect as if such person had originally been a party to this Agreement with respect to such Shares.

(b) If, after giving effect to any arrangements for the purchase of the Shares of a defaulting Underwriter or Underwriters by you and the Company as provided in subsection (a) above, the aggregate number of such Shares which remains unpurchased does not exceed one-tenth of the aggregate number of all the Shares to be purchased at such Time of Delivery, then the Company shall have the right to require each non-defaulting Underwriter to purchase the number of Shares which such Underwriter agreed to purchase hereunder at such Time of Delivery and, in addition, to require each non-defaulting Underwriter to purchase its pro rata share (based on the number of Shares which such Underwriter agreed to purchase hereunder) of the Shares of such defaulting Underwriter or Underwriters for which such arrangements have not been made; but nothing herein shall relieve a defaulting Underwriter from liability for its default.

(c) If, after giving effect to any arrangements for the purchase of the Shares of a defaulting Underwriter or Underwriters by you and the Company as provided in subsection (a) above, the aggregate number of such Shares which remains unpurchased exceeds one-tenth of the aggregate number of all the Shares to be purchased at such Time of Delivery, or if the Company shall not exercise the right described in subsection (b) above to require non-defaulting Underwriters to purchase Shares of a defaulting Underwriter or Underwriters, then this Agreement shall thereupon terminate, without liability on the part of any non-defaulting Underwriter or the Company, except for the expenses to be borne by the Company and the Underwriters as provided in Section 6 hereof and the indemnity and contribution agreements in Section 8 hereof, but nothing herein shall relieve a defaulting Underwriter from liability for its default.

10. Survival. The respective indemnities, agreements, representations, warranties and other statements of the Company and the several Underwriters, as set forth in this Agreement or made by or on behalf of them, respectively, pursuant to this Agreement, shall remain in full force and effect, regardless of any investigation (or any statement as to the results thereof) made by or on behalf of any Underwriter or any controlling person of any Underwriter, or the Company, or any officer or director or controlling person of the Company, and shall survive delivery of and payment for the Shares; and the execution of this Agreement and the consummation of the transactions contemplated herein shall not constitute a waiver of any rights and remedies contained herein. A successor to any Underwriter, or to the Company, its directors or officers or any person controlling the Company, shall be entitled to the benefits of the indemnity, contribution and reimbursement agreements in Section 8.

11. Expenses of Termination. If this Agreement shall be terminated pursuant to Section 9 hereof, the Company shall then have no liability to any Underwriter except as provided in Section 6 and Section 8 hereof; but, if for any other reason this Agreement is terminated, the Company will reimburse the Underwriters for all out-of-pocket expenses approved in writing by you, including fees and disbursements of counsel, reasonably incurred by the Underwriters in making preparations for the purchase, sale and delivery of the Shares not so delivered, but the Company shall have no further liability to any Underwriter in respect of the Shares not so delivered except as provided in Section 6 and Section 8 hereof.

12. Notice. In all dealings hereunder, you shall act on behalf of each of the Underwriters, and the parties hereto shall be entitled to act and rely upon any statement, request, notice or agreement on behalf of any Underwriter made or given by you jointly or by Adams, Harkness & Hill, Inc. on behalf of you as the Underwriters.

All statements, requests, notices and agreements hereunder shall be in writing, and if to the Underwriters shall be delivered or sent by mail or facsimile transmission to you as the Underwriters in care of Adams, Harkness & Hill, Inc., 60 State Street, Boston, MA 02109, Attention: Andrew Pojani; if to the Company shall be delivered or sent by mail or facsimile transmission to the address of the Company

set forth in the Registration Statement, Attention: President; provided, however, that any notice to an Underwriter pursuant to Section 8(c) hereof shall be delivered or sent by mail or facsimile transmission to such Underwriter at its address set forth in its Underwriter’s Questionnaire, which address will be supplied to the Company by you on request. Any such statements, requests, notices or agreements shall take effect upon receipt thereof.

13. Miscellaneous.

(a) This Agreement shall be binding upon, and inure solely to the benefit of, the Underwriters and the Company and, to the extent provided in Sections 8 and 10 hereof, the officers and directors of the Company and each person who controls the Company or any Underwriter, and their respective heirs, executors, administrators, successors and assigns, and no other person shall acquire or have any right under or by virtue of this Agreement. No purchaser of any of the Shares from any Underwriter shall be deemed a successor or assign by reason merely of such purchase.

(b) Time shall be of the essence of this Agreement. As used herein, the term “business day” shall mean any day when the Commission’s office in Washington, D.C. is open for business.

(c) This Agreement shall be governed by and construed in accordance with the laws of The Commonwealth of Massachusetts.

(d) This Agreement may be executed by any one or more of the parties hereto in any number of counterparts, each of which shall be deemed to be an original, but all such counterparts shall together constitute one and the same instrument.

If the foregoing is in accordance with your understanding, please sign and return to us six counterparts hereof, and upon the acceptance hereof by you, on behalf of each of the Underwriters, this letter and such acceptance hereof shall constitute a binding agreement among each of the Underwriters and the Company. It is understood that your acceptance of this letter on behalf of each of the Underwriters is pursuant to the authority set forth in a form of Agreement among Underwriters, the form of which shall be submitted to the Company for examination, upon request, but without warranty on your part as to the authority of the signors thereof.

SCHEDULE I