Exhibit 99.1 AURORA BIOSCIENCES CORPORATION 1996 STOCK PLAN ADOPTED JANUARY 23, 1996 AS AMENDED AND RESTATED AS OF FEBRUARY 4, 1997 AS AMENDED ON APRIL 21, 1998 AS AMENDED ON MAY 28, 1998 AS AMENDED ON MAY 4, 1999 AS AMENDED ON DECEMBER 7, 1999 AS AMENDED ON MARCH 14, 2000 1. PURPOSES. (a) The purpose of the Plan is to provide a means by which selected Employees and Directors of and Consultants to the Company, and its Affiliates, may be given an opportunity to benefit from increases in value of the stock of the Company through the granting of (i) Incentive Stock Options, (ii) Nonstatutory Stock Options, (iii) stock bonuses, (iv) rights to purchase restricted stock, and (v) stock appreciation rights, all as defined below. (b) The Company, by means of the Plan, seeks to retain the services of persons who are now Employees or Directors of or Consultants to the Company or its Affiliates, to secure and retain the services of new Employees, Directors and Consultants, and to provide incentives for such persons to exert maximum efforts for the success of the Company and its Affiliates. (c) The Company intends that the Stock Awards issued under the Plan shall, in the discretion of the Board or any Committee to which responsibility for administration of the Plan has been delegated pursuant to subsection 3(c), be either (i) Options granted pursuant to Section 6 hereof, including Incentive Stock Options and Nonstatutory Stock Options, (ii) stock bonuses or rights to purchase restricted stock granted pursuant to Section 7 hereof, or (iii) stock appreciation rights granted pursuant to Section 8 hereof. All Options shall be separately designated Incentive Stock Options or Nonstatutory Stock Options at the time of grant, and in such form as issued pursuant to Section 6, and a separate certificate or certificates will be issued for shares purchased on exercise of each type of Option. 2. DEFINITIONS. (a) "AFFILIATE" means any parent corporation or subsidiary corporation, whether now or hereafter existing, as those terms are defined in Sections 424(e) and (f) respectively, of the Code. (b) "BOARD" means the Board of Directors of the Company. (c) "CAUSE" shall mean any of the following: (a) an intentional act 1 which materially injures the Company; (b) an intentional refusal or failure to follow lawful and reasonable directions of the Board or an individual to whom a person reports (as appropriate); (c) a willful and habitual neglect of duties; or (d) a conviction of a felony involving moral turpitude which is reasonably likely to inflict or has inflicted material injury on the Company. (d) "CHANGE IN CONTROL" means: (1) a dissolution, liquidation or sale of all or substantially all of the assets of the Company; (2) a merger or consolidation in which the Company is not the surviving corporation; (3) a reverse merger in which the Company is the surviving corporation but the shares of the Company's common stock outstanding immediately preceding the merger are converted by virtue of the merger into other property, whether in the form of securities, cash or otherwise; or (4) after the Listing Date, the acquisition by any person, entity or group within the meaning of Section 13(d) or 14(d) of the Exchange Act or any comparable successor provisions (excluding any employee benefit plan, or related trust, sponsored or maintained by the Company or any Affiliate of the Company) of the beneficial ownership (within the meaning of Rule 13d-3 promulgated under the Exchange Act, or comparable successor rule) of securities of the Company representing at least fifty percent (50%) of the combined voting power entitled to vote in the election of directors. (e) "CODE" means the Internal Revenue Code of 1986, as amended. (f) "COMMITTEE" means a Committee appointed by the Board in accordance with subsection 3(c) of the Plan. (g) "COMPANY" means Aurora Biosciences Corporation, a Delaware corporation. (h) "CONCURRENT STOCK APPRECIATION RIGHT" or "CONCURRENT RIGHT" means a right granted pursuant to subsection 8(b)(2) of the Plan. (i) "CONSTRUCTIVELY TERMINATED" shall mean the voluntary termination of Continuous Status as an Employee, Director or Consultant by a person within fifteen (15) days after any of the following are undertaken without such person's express written consent: (a) the assignment to such person of any duties or responsibilities which result in a material diminution or adverse change of such person's position, status or circumstances of employment or engagement, other than a mere change in title or reporting relationship; (b)reduction by the Company in such person's base salary or compensation; (c) any failure by the Company to continue in effect any benefit plan or arrangement, including incentive plans or plans to receive securities of the Company, in which such person is participating (hereinafter referred to as "Benefit Plans"), or the taking of any action by the Company which would adversely affect such person's participation in or reduce such person's benefits under any Benefit Plans or deprive such person of any fringe benefit then enjoyed by such person, provided, however, that such person's termination shall not be deemed to be Constructively Terminated if the Company offers a range of benefit plans and programs which, taken as a whole, are comparable to the Benefit Plans; (d) a relocation of such person or the Company's principal business offices to a location more than fifty (50) miles from the location at which such person performs duties, except for required travel by such person on the Company's business to an extent substantially consistent with such person's business travel obligations; (e) any breach by the Company of any material agreement between such person and the Company concerning such person's employment or engagement; or (f) any 2 failure by the Company to obtain the assumption of any material agreement between such person and the Company concerning such person's employment or engagement by any successor or assign of the Company. (j) "CONSULTANT" means any person, including an advisor, engaged by the Company or an Affiliate to render consulting services and who is compensated for such services, provided that the term "Consultant" shall not include Directors who are paid only a director's fee by the Company or who are not compensated by the Company for their services as Directors. (k) "CONTINUOUS STATUS AS AN EMPLOYEE, DIRECTOR OR CONSULTANT" means that the service of an individual to the Company, whether as an Employee, Director or Consultant is not interrupted or terminated. The Board, in its sole discretion, may determine whether Continuous Status as an Employee, Director or Consultant shall be considered interrupted in the case of: (i) any leave of absence approved by the Board, including sick leave, military leave, or any other personal leave; or (ii) transfers between locations of the Company or between the Company, Affiliates or their successors. (l) "COVERED EMPLOYEE" means the chief executive officer and the four (4) other highest compensated officers of the Company for whom total compensation is required to be reported to stockholders under the Exchange Act, as determined for purposes of Section 162(m) of the Code. (m) "DIRECTOR" means a member of the Board. (n) "DISABILITY" means permanent and total disability as defined in Section 422(c)(6) of the Code. (o) "EMPLOYEE" means any person, including Officers and Directors, employed by the Company or any Affiliate of the Company. Neither service as a Director nor payment of a director's fee by the Company shall be sufficient to constitute "employment" by the Company. (p) "EXCHANGE ACT" means the Securities Exchange Act of 1934, as amended. (q) "FAIR MARKET VALUE" means, as of any date, the value of the common stock determined as follows and, in each case, in a manner consistent with Section 260.140.50 of Title 10 of the California Code of Regulations: (i) If the common stock is listed on any established stock exchange or a national market system, including without limitation the National Market System of the National Association of Securities Dealers, Inc. Automated Quotation ("NASDAQ") System, the Fair Market Value of a share of common stock shall be the closing sales price for such stock (or the closing bid, if no sales were reported) as quoted on such system or exchange (or the exchange with the greatest volume of trading in common stock) on the last market trading day prior to the day of determination, as reported in the Wall Street Journal or such other source as the Board deems reliable; (ii) If the common stock is quoted on the NASDAQ System (but not on the National Market System thereof) or is regularly quoted by a recognized securities dealer but selling prices are not reported, the Fair Market Value of a share of Common Stock shall be the mean between the bid and asked prices for the common stock on the last market trading day prior to the 3 day of determination, as reported in the Wall Street Journal or such other source as the Board deems reliable; (iii) In the absence of an established market for the common stock, the Fair Market Value shall be determined in good faith by the Board. (r) "INCENTIVE STOCK OPTION" means an Option intended to qualify as an incentive stock option within the meaning of Section 422 of the Code and the regulations promulgated thereunder. (s) "INDEPENDENT STOCK APPRECIATION RIGHT" or "INDEPENDENT RIGHT" means a right granted pursuant to subsection 8(b)(3) of the Plan. (t) "LISTING DATE" means the first date upon which any security of the Company is listed (or approved for listing) upon notice of issuance on any securities exchange, or designated (or approved for designation) upon notice of issuance as a national market security on an interdealer quotation system if such securities exchange or interdealer quotation system has been certified in accordance with the provisions of Section 25100(o) of the California Corporate Securities Law of 1968. (u) "NON-EMPLOYEE DIRECTOR" means a Director who either (i) is not a current Employee or Officer of the Company or its parent or subsidiary, does not receive compensation (directly or indirectly) from the Company or its parent or subsidiary for services rendered as a consultant or in any capacity other than as a Director (except for an amount as to which disclosure would not be required under Item 404(a) of Regulation S-K promulgated pursuant to the Securities Act("Regulation S-K")), does not possess an interest in any other transaction as to which disclosure would be required under Item 404(a) of Regulation S-K, and is not engaged in a business relationship as to which disclosure would be required under Item 404(b) of Regulation S-K; or (ii) is otherwise considered a "non-employee" for purposes of Rule 16b-3. (v) "NONSTATUTORY STOCK OPTION" means an Option not intended to qualify as an Incentive Stock Option. (w) "OFFICER" means a person who is an officer of the Company within the meaning of Section 16 of the Exchange Act and the rules and regulations promulgated thereunder. (x) "OPTION" means a stock option granted pursuant to the Plan. (y) "OPTION AGREEMENT" means a written agreement between the Company and an Optionee evidencing the terms and conditions of an individual Option grant. Each Option Agreement shall be subject to the terms and conditions of the Plan. (z) "OPTIONEE" means a person to whom an Option is granted pursuant to the Plan or, if applicable, such other person who holds an outstanding Option. (aa) "OUTSIDE DIRECTOR" means a Director who either (i) is not a current employee of the Company or an "affiliated corporation" (within the meaning of the Treasury regulations promulgated under Section 162(m) of the Code), is not a former employee of the Company or an "affiliated corporation" receiving compensation for prior services (other than benefits under a tax qualified pension plan), was not an officer of the Company or an "affiliated 4 corporation" at any time, and is not currently receiving direct or indirect remuneration from the Company or an "affiliated corporation" for services in any capacity other than as a Director, or (ii) is otherwise considered an "outside director" for purposes of Section 162(m) of the Code. (bb) "PLAN" mans this 1996 Stock Plan. (cc) "RULE 16b-3" means Rule 16b-3 of the Exchange Act or any successor to Rule 16b-3, as in effect with respect to the Company when discretion is being exercised regarding the Plan. (dd) "SECURITIES ACT" means the Securities Act of 1933, as amended. (ee) "STOCK APPRECIATION RIGHT" means any of the various types of rights which may be granted under Section 8 of the Plan. (ff) "STOCK AWARD" means any right granted under the Plan, including any Option, any stock bonus, any right to purchase restricted stock, and any Stock Appreciation Right. (gg) "STOCK AWARD AGREEMENT" means a written agreement between the Company and a holder of a Stock Award evidencing the terms and conditions of an individual Stock Award grant. Each Stock Award Agreement shall be subject to the terms and conditions of the Plan. (hh) "SURVIVING STOCK AWARDS" shall have the meaning set forth in Section 13(b) of the Plan. (ii) "TANDEM STOCK APPRECIATION RIGHT" or "TANDEM RIGHT" means a right granted pursuant to subsection 8(b)(1) of the Plan. 3. ADMINISTRATION. (a) The Plan shall be administered by the Board unless and until the Board delegates administration to a Committee, as provided in subsection 3(c). (b) The Board shall have the power, subject to, and within the limitations of, the express provisions of the Plan: (1) To determine from time to time which of the persons eligible under the Plan shall be granted Stock Awards; when and how each Stock Award shall be granted; whether a Stock Award will be an Incentive Stock Option, a Nonstatutory Stock Option, a stock bonus, a right to purchase restricted stock, a Stock Appreciation Right, or a combination of the foregoing; the provisions of each Stock Award granted (which need not be identical), including the time or times when a person shall be permitted to receive stock pursuant to a Stock Award; whether a person shall be permitted to receive stock upon exercise of an Independent Stock Appreciation Right; and the number of shares with respect to which a Stock Award shall be granted to each such person. (2) To construe and interpret the Plan and Stock Awards granted under it, and to establish, amend and revoke rules and regulations for its administration. The Board, in the exercise of this power, may correct any defect, omission or inconsistency in the Plan or in any Stock Award 5 Agreement, in a manner and to the extent it shall deem necessary or expedient to make the Plan fully effective. (3) To amend the Plan or a Stock Award as provided in Section 14. (4) Generally, to exercise such powers and to perform such acts as the Board deems necessary or expedient to promote the best interests of the Company which are not in conflict with the provisions of the Plan. (c) The Board may delegate administration of the Plan to a committee of the Board composed of not fewer than two (2) members (the "Committee"), all of the members of which Committee may be, in the discretion of the Board, Non-Employee Directors and/or Outside Directors. If administration is delegated to a Committee, the Committee shall have, in connection with the administration of the Plan, the powers theretofore possessed by the Board, including the power to delegate to a subcommittee of two (2) or more Outside Directors any of the administrative powers the Committee is authorized to exercise (and references in this Plan to the Board shall thereafter be to the Committee or such a subcommittee), subject, however, to such resolutions, not inconsistent with the provisions of the Pla, as may be adopted from time to time by the Board. The Board may abolish the Committee at any time and revest in the Board the administration of the Plan. Additionally, prior to the Listing Date, and notwithstanding anything to the contrary contained herein, the Board may delegate administration of the Plan to a committee of one or more members of the Board and the term Committee shall apply to any person or persons to whom such authority has been delegated. Notwithstanding anything in this Section 3 to the contrary, the Board or the Committee may delegate to a committee of one or more members of the Board the authority to grant Stock Awards to eligible persons who (1) are not then subject to Section 16 of the Exchange Act and/or (2) are either (i) not then Covered Employees and are not expected to be Covered Employees at the time of recognition of income resulting from such Stock Award, or (ii) not persons with respect to whom the Company wishes to comply with Section 162(m) of the Code. 4. SHARES SUBJECT TO THE PLAN. (a) Subject to the provisions of Section 13 relating to adjustments upon changes in stock, the stock that may be issued pursuant to Stock Awards shall not exceed in the aggregate eight million (8,000,000) shares of the Company's common stock. If any Stock Award shall for any reason expire or otherwise terminate, in whole or in part, without having been exercised in full, the stock not acquired under such Stock Award shall revert to and again become available for issuance under the Plan. Shares subject to Stock Appreciation Rights exercised in accordance with Section 8 of the Plan shall not be available for subsequent issuance under the Plan. (b) The stock subject to the Plan may be unissued shares or reacquired shares, bought on the market or otherwise. 5. ELIGIBILITY. (a) Incentive Stock Options and Stock Appreciation Rights appurtenant thereto may be granted only to Employees. Stock Awards other than Incentive Stock Options and Stock Appreciation Rights appurtenant thereto may be granted only to Employees, Directors or Consultants. 6 (b) No person shall be eligible for the grant of an Option or an award to purchase restricted stock if, at the time of grant, such person owns (or is deemed to own pursuant to Section 424(d) of the Code) stock possessing more than ten percent (10%) of the total combined voting power of all classes of stock of the Company or of any of its Affiliates unless the exercise price of such Option is at least one hundred ten percent (110%) of the Fair Market Value of such stock at the date of grant and the Option is not exercisable after the expiration of five (5) years from the date of grant, or in the case of a restricted stock purchase award, the purchase price is at least one hundred percent (100%) of the Fair Market Value of such stock at the date of grant. (c) Subject to the provisions of Section 13 relating to adjustments upon changes in stock, no person shall be eligible to be granted Options and Stock Appreciation Rights covering more than five hundred thousand (500,000) shares of the Company's common stock in any twelve (12) month period. This subsection 5(c)shall not apply prior to the Listing Date and, following the Listing Date, shall not apply until (i) the earliest of: (A) the first material modification of the Plan (including any increase to the number of shares reserved for issuance under the Plan in accordance with Section 4); (B) the issuance of all of the shares of common stock reserved for issuance under the Plan; (C) the expiration of the Plan; or (D) the first meeting of stockholders at which directors are to be elected that occurs after the close of the third calendar year following the calendar year in which occurred the first registration of an equity security under section 12 of the Exchange Act; or (ii) such other date required by Section 162(m) of the Code and the rules and regulations promulgated thereunder. 6. OPTION PROVISIONS. Each Option shall be in such form and shall contain such terms and conditions as the Board shall deem appropriate. The provisions of separate Options need not be identical, but each Option shall include (through incorporation of provisions hereof by reference in the Option or otherwise) the substance of each of the following provisions: (a) TERM. No Option shall be exercisable after the expiration of ten (10) years from the date it was granted. (b) PRICE. The exercise price of each Incentive Stock Option shall be not less than one hundred percent (100%) of the Fair Market Value of the stock subject to the Option on the date the Option is granted; the exercise price of each Nonstatutory Stock Option shall be not less than eighty-five percent (85%)of the Fair Market Value of the stock subject to the Option on the date the Option is granted. Notwithstanding the foregoing, an Option (whether an Incentive Stock Option or a Nonstatutory Stock Option) may be granted with an exercise price lower than that set forth in the preceding sentence if such Option is granted pursuant to an assumption or substitution for another option in a manner satisfying the provisions of Section 424(a) of the Code. (c) CONSIDERATION. The purchase price of stock acquired pursuant to an Option shall be paid, to the extent permitted by applicable statutes and regulations, either (i) in cash at the time the Option is exercised, or (ii) at the discretion of the Board or the Committee, at the time of the grant of the Option, (A) by delivery to the Company of other common stock of the 7 Company, or (B) in any other form of legal consideration that may be acceptable to the Board. (d) TRANSFERABILITY. An Option shall not be transferable except by will or by the laws of descent and distribution, and shall be exercisable during the lifetime of the person to whom the Option is granted only by such person; provided, however, that, after the Listing Date, to the extent permitted by applicable law, a Nonstatutory Stock Option shall be transferable by the person to whom such Option is granted upon such terms and conditions as are set forth in the Option Agreement for such Nonstatutory Stock Option, as the Board or Committee shall determine in its discretion. Notwithstanding the foregoing, the person to whom the Option is granted may, by delivering written notice to the Company, in a form satisfactory to the Company, designate a third party who, in the event of the death of the Optionee, shall thereafter be entitled to exercise the Option. (e) VESTING. The total number of shares of stock subject to an Option may, but need not, be allotted in periodic installments (which may, but need not, be equal). The Option Agreement may provide that from time to time during each of such installment periods, the Option may become exercisable ("vest") with respect to some or all of the shares allotted to that period, and may be exercised with respect to some or all of the shares allotted to such period and/or any prior period as to which the Option became vested but was not fully exercised. The Option may be subject to such other terms and conditions on the time or times when it may be exercised (which may be based on performance or other criteria) as the Board may deem appropriate. The vesting provisions of individual Options may vary but in each case will provide for vesting of at least twenty percent (20%) per year of the total number of shares subject to the Option. The provisions of this subsection 6(e) are subject to any Option provisions governing the minimum number of shares as to which an Option may be exercised. (f) TERMINATION OF EMPLOYMENT OR RELATIONSHIP AS A DIRECTOR OR CONSULTANT. In the event an Optionee's Continuous Status as an Employee, Director or Consultant terminates (other than upon the Optionee's death or Disability), the Optionee may exercise his or her Option (to the extent that the Optionee was entitled to exercise it as of the date of termination) but only within such period of time ending on the earlier of (i) the date three (3) months following the termination of the Optionee's Continuous Status as an Employee, Director or Consultant (or such longer or shorter period, which shall not be less than thirty (30) days, specified in the Option Agreement), or (ii) the expiration of the term of the Option as set forth in the Option Agreement. If, after termination, the Optionee does not exercise his or her Option within the time specified in the Option Agreement, the Option shall terminate, and the shares covered by such Option shall revert to and again become available for issuance under the Plan. An Optionee's Option Agreement may also provide that if the exercise of the Option following the termination of the Optionee's Continuous Status as an Employee, Director, or Consultant (other than upon the Optionee's death or Disability) would result in liability under Section 16(b) of the Exchange Act, then the Option shall terminate on the earlier of (i) the expiration of the term of the Option set forth in the Option Agreement, or (ii) the tenth (10th) day after the last date on which such exercise would result in such liability under Section 16(b) of the Exchange Act. Finally, an Optionee's Option Agreement may also provide that if the exercise of the Option following the termination of the Optionee's Continuous Status as an Employee, 8 Director or Consultant (other than upon the Optionee's death or Disability) would be prohibited at any time solely because the issuance of shares would violate the registration requirements under the Securities Act, then the Option shall terminate on the earlier of (i) the expiration of the term of the Option set forth in the first paragraph of this subsection 6(f), or (ii) the expiration of a period of three (3) months after the termination of the Optionee's Continuous Status as an Employee, Director or Consultant during which the exercise of the Option would not be in violation of such registration requirements. (g) DISABILITY OF OPTIONEE. In the event an Optionee's Continuous Status as an Employee, Director or Consultant terminates as a result of the Optionee's Disability, the Optionee may exercise his or her Option (to the extent that the Optionee was entitled to exercise it as of the date of termination), but only within such period of time ending on the earlier of (i) the date twelve (12) months following such termination (or such longer or shorter period, which in no event shall be less than six (6) months, specified in the Option Agreement), or (ii) the expiration of the term of the Option as set forth in the Option Agreement. If, at the date of termination, the Optionee is not entitled to exercise his or her entire Option, the shares covered by the unexercisable portion of the Option shall revert to and again become available for issuance under the Plan. If, after termination, the Optionee does not exercise his or her Option within the time specified herein, the Option shall terminate, and the shares covered by such Option shall revert to and again become available for issuance under the Plan. (h) DEATH OF OPTIONEE. In the event of the death of an Optionee during, or within a period specified in the Option Agreement after the termination of, the Optionee's Continuous Status as an Employee, Director or Consultant, the Option may be exercised (to the extent the Optionee was entitled to exercise the Option as of the date of death) by the Optionee's estate, by a person who acquired the right to exercise the Option by bequest or inheritance or by a person designated to exercise the option upon the Optionee's death pursuant to subsection 6(d), but only within the period ending on the earlier of (i) the date eighteen (18) months following the date of death (or such longer or shorter period, which in no event shall be less than six (6) months, specified in the Option Agreement), or (ii) the expiration of the term of such Option as set forth in the Option Agreement. If, at the time of death, the Optionee was not entitled to exercise his or her entire Option, the shares covered by the unexercisable portion of the Option shall revert to and again become available for issuance under the Plan. If, after death, the Option is not exercised within the time specified herein, the Option shall terminate, and the shares covered by such Option shall revert to and again become available for issuance under the Plan. (i) EARLY EXERCISE. The Option may, but need not, include a provision whereby the Optionee may elect at any time while an Employee, Director or Consultant to exercise the Option as to any part or all of the shares subject to the Option prior to the full vesting of the Option. Any unvested shares so purchased shall be subject to a repurchase right in favor of the Company, with the repurchase price to be equal to the original purchase price of the stock, or to any other restriction the Board determines to be appropriate; provided, however, that (i) the right to repurchase at the original purchase price shall lapse at a minimum rate of twenty percent (20%) per year over five (5) years from the date the Option was granted, and (ii) such right shall be exercisable only within (A) the ninety (90) day period following the termination of employment or the relationship as a Director or Consultant, or 9 (B) such longer period as may be agreed to by the Company and the Optionee (for example, for purposes of satisfying the requirements of Section 1202(c)(3) of the Code (regarding "qualified small business stock")), and (iii) such right shall be exercisable only for cash or cancellation of purchase money indebtedness for the shares. Should the right of repurchase be assigned by the Company, the assignee shall pay the Company cash equal to the difference between the original purchase price and the stock's Fair Market Value if the original purchase price is less than the stock's Fair Market Value. (j) RIGHT OF REPURCHASE. The Option may, but need not, include a provision whereby the Company may elect, prior to the Listing Date, to repurchase all or any part of the vested shares exercised pursuant to the Option; provided, however, that (i) such repurchase right shall be exercisable only within (A) the ninety (90) day period following the termination of employment or the relationship as a Director or Consultant and (ii) such right shall be exercisable only for cash or cancellation of purchase money indebtedness for the shares at a repurchase price equal to the greater of (A) the stock's Fair Market Value at the time of such termination, or (B) the original purchase price paid for such shares by the Optionee. (k) RIGHT OF FIRST REFUSAL. The Option may, but need not, include a provision whereby the Company may elect, prior to the Listing Date, to exercise a right of first refusal following receipt of notice from the Optionee of the intent to transfer all or any part of the shares exercised pursuant to the Option. (l) RE-LOAD OPTIONS. Without in any way limiting the authority of the Board or Committee to make or not to make grants of Options hereunder, the Board or Committee shall have the authority (but not an obligation) to include as part of any Option Agreement a provision entitling the Optionee to a further Option (a "Re-Load Option") in the event the Optionee exercises the Option evidenced by the Option agreement, in whole or in part, by surrendering other shares of Common Stock in accordance with this Plan and the terms and conditions of the Option Agreement. Any such Re-Load Option (i) shall be for a number of shares equal to the number of shares surrendered as part or all of the exercise price of such Option; (ii) shall have an expiration date which is the same as the expiration date of the Option the exercise of which gave rise to such Re-Load Option; and (iii) shall have an exercise price which is equal to one hundred percent (100%) of the Fair Market Value of the Common Stock subject to the Re-Load Option on the date of exercise of the original Option. Notwithstanding the foregoing, a Re-Load Option which is granted to a 10% stockholder (as described in subsection 5(b)), shall have an exercise price which is equal to one hundred ten percent (110%) of the Fair Market Value of the stock subject to the Re-Load Option on the date of exercise of the original Option and shall have a term which is no longer than five (5)years. Any such Re-Load Option may be an Incentive Stock Option or a Nonstatutory Stock Option, as the Board or Committee may designate at the time of the grant of the original Option; provided, however, that the designation of any Re-Load Option as an Incentive Stock Option shall be subject to the one hundred thousand dollar ($100,000) annual limitation on exercisability of Incentive Stock Options described in subsection 12(e) of the Plan and in Section 422(d) of the Code. There shall be no Re-Load Options on a Re-Load Option. Any such Re-Load Option shall be subject to the availability of sufficient shares under subsection 4(a) and the limits on the 10 grants of Options under subsection 5(c) and shall be subject to such other terms and conditions as the Board or Committee may determine which are not inconsistent with the express provisions of the Plan regarding the terms of Options. 7. TERMS OF STOCK BONUSES AND PURCHASES OF RESTRICTED STOCK. Each stock bonus or restricted stock purchase agreement shall be in such form and shall contain such terms and conditions as the Board or the Committee shall deem appropriate. The terms and conditions of stock bonus or restricted stock purchase agreements may change from time to time, and the terms and conditions of separate agreements need not be identical, but each stock bonus or restricted stock purchase agreement shall include (through incorporation of provisions hereof by reference in the agreement or otherwise) the substance of each of the following provisions as appropriate: (a) PURCHASE PRICE. The purchase price under each restricted stock purchase Stock Award Agreement shall be such amount as the Board or Committee shall determine and designate in such agreement, but in no event shall the purchase price be less than eighty-five percent (85%) of the stock's Fair Market Value on the date such award is made. Notwithstanding the foregoing, the Board or the Committee may determine that eligible participants in the Plan may be awarded stock pursuant to a stock bonus agreement in consideration for past services actually rendered to the Company or for its benefit. (b) TRANSFERABILITY. No rights under a stock bonus or restricted stock purchase agreement shall be transferable except by will or the laws of descent and distribution or pursuant to a QDRO satisfying the requirements of Rule 16b-3 and any administrative interpretations or pronouncements thereunder, so long as stock awarded under such agreement remains subject to the terms of the agreement. (c) CONSIDERATION. The purchase price of stock acquired pursuant to a stock purchase agreement shall be paid either: (i) in cash at the time of purchase; or (ii) in any other form of legal consideration that may be acceptable to the Board or the Committee in its discretion. Notwithstanding the foregoing, the Board or the Committee to which administration of the Plan has been delegated may award stock pursuant to a stock bonus agreement in consideration for past services actually rendered to the Company or for its benefit. (d) VESTING. Shares of stock sold or awarded under the Plan may, but need not, be subject to a repurchase option in favor of the Company in accordance with a vesting schedule to be determined by the Board or the Committee. The applicable agreement shall provide (i) that the right to repurchase at the original purchase price shall lapse at a minimum rate of twenty percent (25%) per year over four (4) years from the date the Stock Award was granted, and (ii) such right shall be exercisable only (A) within the ninety (90) day period following the termination of employment or the relationship as a Director or Consultant, or (B) such longer period as may be agreed to by the Company and the holder of the Stock Award (for example, for purposes of satisfying the requirements of Section 1202(c)(3) of the Code (regarding "qualified small business stock")), and (iii) such right shall be exercisable only for cash or cancellation of purchase money indebtedness for the shares. Should the right of repurchase be assigned by the Company, the assignee shall pay the Company cash equal to the difference between the 11 original purchase price and the stock's Fair Market Value if the original purchase price is less than the stock's Fair Market Value. (e) TERMINATION OF EMPLOYMENT OR RELATIONSHIP AS A DIRECTOR OR CONSULTANT. In the event a participant's Continuous Status as an Employee, Director or Consultant terminates, the Company may repurchase or otherwise reacquire, subject to the limitations described in subsection 7(d), any or all of the shares of stock held by that person which have not vested as of the date of termination under the terms of the stock bonus or restricted stock purchase agreement between the Company and such person. 8. STOCK APPRECIATION RIGHTS. (a) The Board or Committee shall have full power and authority, exercisable in its sole discretion, to grant Stock Appreciation Rights under the Plan to Employees or Directors of or Consultants to, the Company or its Affiliates. To exercise any outstanding Stock Appreciation Right, the holder must provide written notice of exercise to the Company in compliance with the provisions of the Stock Award Agreement evidencing such right. If a Stock Appreciation Right is granted to an individual who is at the time of grant subject to Section 16(b) of the Exchange Act, the Stock Award Agreement shall incorporate all the terms and conditions at the time necessary to assure that the subsequent exercise of such right shall qualify for the safe-harbor exemption from short-swing profit liability provided by Rule 16b-3 promulgated under the Exchange Act (or any successor rule or regulation). Except as provided in subsection 5(c), no limitation shall exist on the aggregate amount of cash payments the Company may make under the Plan in connection with the exercise of a Stock Appreciation Right. (b) Three types of Stock Appreciation Rights shall be authorized for issuance under the Plan: (1) TANDEM STOCK APPRECIATION RIGHTS. Tandem Stock Appreciation Rights will be granted appurtenant to an Option, and shall, except as specifically set forth in this Section 8, be subject to the same terms and conditions applicable to the particular Option grant to which it pertains. Tandem Stock Appreciation Rights will require the holder to elect between the exercise of the underlying Option for shares of stock and the surrender, in whole or in part, of such Option for an appreciation distribution. The appreciation distribution payable on the exercised Tandem Right shall be in cash (or, if so provided, in an equivalent number of shares of stock based on Fair Market Value on the date of the Option surrender) in an amount up to the excess of (A) the Fair Market Value (on the date of the Option surrender) of the number of shares of stock covered by that portion of the surrendered Option in which the Optionee is vested over (B) the aggregate exercise price payable for such vested shares. (2) CONCURRENT STOCK APPRECIATION RIGHTS. Concurrent Rights will be granted appurtenant to an Option and may apply to all or any portion of the shares of stock subject to the underlying Option and shall, except as specifically set forth in this Section 8, be subject to the same terms and conditions applicable to the particular Option grant to which it pertains. A Concurrent Right shall be exercised automatically at the same time the underlying Option is exercised with respect to the particular shares of stock to which the Concurrent Right pertains. The appreciation distribution payable on an exercised Concurrent Right shall be in cash (or, if so provided, in an 12 equivalent number of shares of stock based on Fair Market Value on the date of the exercise of the Concurrent Right) in an amount equal to such portion as shall be determined by the Board or the Committee at the time of the grant of the excess of (A) the aggregate Fair Market Value (on the date of the exercise of the Concurrent Right) of the vested shares of stock purchased under the underlying Option which have Concurrent Rights appurtenant to them over (B) the aggregate exercise price paid for such shares. (3) INDEPENDENT STOCK APPRECIATION RIGHTS. Independent Rights will be granted independently of any Option and shall, except as specifically set forth in this Section 8, be subject to the same terms and conditions applicable to Nonstatutory Stock Options as set forth in Section 6. They shall be denominated in share equivalents. The appreciation distribution payable on the exercised Independent Right shall be not greater than an amount equal to the excess of (A) the aggregate Fair Market Value (on the date of the exercise of the Independent Right) of a number of shares of Company stock equal to the number of share equivalents in which the holder is vested under such Independent Right, and with respect to which the holder is exercising the Independent Right on such date, over (B) the aggregate Fair Market Value (on the date of the grant of the Independent Right) of such number of shares of Company stock. The appreciation distribution payable on the exercised Independent Right shall be in cash or, if so provided, in an equivalent number of shares of stock based on Fair Market Value on the date of the exercise of the Independent Right. 9. CANCELLATION AND RE-GRANT OF OPTIONS. (a) The Board or the Committee shall have the authority to effect, at any time and from time to time, (i) the repricing of any outstanding Options and/or any Stock Appreciation Rights under the Plan and/or (ii) with the consent of the affected holders of Options and/or Stock Appreciation Rights, the cancellation of any outstanding Options and/or any Stock Appreciation Rights under the Plan and the grant in substitution therefor of new Options and/or Stock Appreciation Rights under the Plan covering the same or different numbers of shares of stock, but having an exercise price per share not less than eighty-five percent (85%) of the Fair Market Value (one hundred percent (100%) of the Fair Market Value in the case of an Incentive Stock Option) or, in the case of a 10% stockholder (as described in subsection 5(b)), not less than one hundred ten percent (110%) of the Fair Market Value) per share of stock on the new grant date. Notwithstanding the foregoing, the Board or the Committee may grant an Option and/or Stock Appreciation Right with an exercise price lower than that set forth above if such Option and/or Stock Appreciation Right is granted as part of a transaction to which section 424(a) of the Code applies. (b) Shares subject to an Option or Stock Appreciation Right canceled under this Section 9 shall continue to be counted against the maximum award of Options and Stock Appreciation Rights permitted to be granted pursuant to subsection 5(c) of the Plan. The repricing of an Option and/or Stock Appreciation Right under this Section 9, resulting in a reduction of the exercise price, shall be deemed to be a cancellation of the original Option and/or Stock Appreciation Right and the grant of a substitute Option and/or Stock Appreciation Right; in the event of such repricing, both the original and the substituted Options and Stock Appreciation Rights shall be counted against the maximum awards of Options and Stock Appreciation Rights permitted to be granted pursuant to subsection 5(c) of the Plan. The provisions of this subsection 9(b) shall be applicable only to the extent required by Section 162(m) of the Code. 13 10. COVENANTS OF THE COMPANY. (a) During the terms of the Stock Awards, the Company shall keep available at all times the number of shares of stock required to satisfy such Stock Awards. (b) The Company shall seek to obtain from each regulatory commission or agency having jurisdiction over the Plan such authority as may be required to issue and sell shares of stock upon exercise of the Stock Award; provided, however, that this undertaking shall not require the Company to register under the Securities Act either the Plan, any Stock Award or any stock issued or issuable pursuant to any such Stock Award. If, after reasonable efforts, the Company is unable to obtain from any such regulatory commission or agency the authority which counsel for the Company deems necessary for the lawful issuance and sale of stock under the Plan, the Company shall be relieved from any liability for failure to issue and sell stock upon exercise of such Stock Awards unless and until such authority is obtained. 11. USE OF PROCEEDS FROM STOCK. Proceeds from the sale of stock pursuant to Stock Awards shall constitute general funds of the Company. 12. MISCELLANEOUS. (a) Neither an Employee, Director or Consultant nor any person to whom a Stock Award is transferred under subsection 6(d), 7(b), or 8(b) shall be deemed to be the holder of, or to have any of the rights of a holder with respect to, any shares subject to such Stock Award unless and until such person has satisfied all requirements for exercise of the Stock Award pursuant to its terms. (b) Throughout the term of any Stock Award, the Company shall deliver to the holder of such Stock Award, not later than one hundred twenty (120) days after the close of each of the Company's fiscal years during the term of such Stock Award, a balance sheet and an income statement. This subsection shall not apply when issuance is limited to key employees whose duties in connection with the Company assure them access to equivalent information. (c) Nothing in the Plan or any instrument executed or Stock Award granted pursuant thereto shall confer upon any Employee, Director, Consultant or other holder of Stock Awards any right to continue in the employ of the Company or any Affiliate (or to continue acting as a Director or Consultant) or shall affect the right of the Company or any Affiliate to terminate the employment of any Employee with or without cause, the right of the Company's Board of Directors and/or the Company's stockholders to remove any Director as provided in the Company's By-Laws and the provisions of the Delaware General Corporation Law or the right to terminate the relationship of any Consultant subject to the terms of such Consultant's agreement with the Company or Affiliate. (d) To the extent that the aggregate Fair Market Value (determined at the time of grant) of stock with respect to which Incentive Stock Options are exercisable for the first time by any Optionee during any calendar year under 14 all plans of the Company and its Affiliates exceeds one hundred thousand dollars ($100,000), the Options or portions thereof which exceed such limit (according to the order in which they were granted) shall be treated as Nonstatutory Stock Options. (e) The Company may require any person to whom a Stock Award is granted, or any person to whom a Stock Award is transferred pursuant to subsection 6(d), 7(b) or 8(b), as a condition of exercising or acquiring stock under any Stock Award, (1) to give written assurances satisfactory to the Company as to such person's knowledge and experience in financial and business matters and/or to employ a purchaser representative reasonably satisfactory to the Company who is knowledgeable and experienced in financial and business matters, and that he or she is capable of evaluating, alone or together with the purchaser representative, the merits and risks of exercising the Stock Award; and (2) to give written assurances satisfactory to the Company stating that such person is acquiring the stock subject to the Stock Award for such person's own account and not with any present intention of selling or otherwise distributing the stock. The foregoing requirements, and any assurances given pursuant to such requirements, shall be inoperative if (i) the issuance of the shares upon the exercise or acquisition of stock under the Stock Award has been registered under a then currently effective registration statement under the Securities Act, or (ii) as to any particular requirement, a determination is made by counsel for the Company that such requirement need not be met in the circumstances under the then applicable securities laws. The Company may, upon advice of counsel to the Company, place legends on stock certificates issued under the Plan as such counsel deems necessary or appropriate in order to comply with applicable securities laws, including, but not limited to, legends restricting the transfer of the stock. (f) To the extent provided by the terms of a Stock Award Agreement, the person to whom a Stock Award is granted may satisfy any federal, state or local tax withholding obligation relating to the exercise or acquisition of stock under a Stock Award by any of the following means or by a combination of such means: (1) tendering a cash payment; (2) authorizing the Company to withhold shares from the shares of the common stock otherwise issuable to the participant as a result of the exercise or acquisition of stock under the Stock Award; or (3) delivering to the Company owned and unencumbered shares of the common stock of the Company. 13. ADJUSTMENTS UPON CHANGES IN STOCK. (a) If any change is made in the stock subject to the Plan, or subject to any Stock Award (through merger, consolidation, reorganization, recapitalization, reincorporation, stock dividend, dividend in property other than cash, stock split, liquidating dividend, combination of shares, exchange of shares, change in corporate structure or other transaction not involving the receipt of consideration by the Company), the Plan will be appropriately adjusted in the type(s) and maximum number of securities subject to the Plan pursuant to subsection 4(a) and the maximum number of securities subject to award to any person during any twelve (12) month period pursuant to subsection 5(c), and the outstanding Stock Awards will be appropriately adjusted in the type(s) and number of securities and price per share of stock subject to such outstanding Stock Awards. Such adjustments shall be made by the Board or the Committee, the determination of which shall be final, binding and conclusive. (The conversion of any convertible securities of the 15 Company shall not be treated as a "transaction not involving the receipt of consideration by the Company".) (b) In the event of a Change in Control, then: (i) any surviving or acquiring corporation shall assume any Stock Awards outstanding under the Plan or shall substitute similar stock awards (including an award to acquire the same consideration paid to the stockholders in such Change in Control) for those outstanding under the Plan (such assumed or substituted stock awards are collectively referred to herein as the "SURVIVING STOCK AWARDS"), or (ii) in the event any surviving or acquiring corporation refuses to assume such Stock Awards or to substitute similar stock awards for those outstanding under the Plan (A)with respect to Stock Awards held by persons performing services as Employees, Directors or Consultants immediately prior to the effective date of such Change in Control, subject to any applicable provisions of the California Corporate Securities Law of 1968 and related regulations relied upon as a condition of issuing securities pursuant to the Plan, the vesting of such Stock Awards (and, if applicable, the time during which such Stock Awards may be exercised) shall be accelerated prior to such event and such Stock Awards terminated if not exercised (if applicable) after such acceleration and at or prior to such event, and (B) unless otherwise provided in this Section 13, with respect to any other Stock Awards outstanding under the Plan, such Stock Awards shall be terminated if not exercised (if applicable) prior to the effective date of such Change in Control. (c) In addition, with respect to any person (i) who is Constructively Terminated within the sixty (60) day period immediately preceding the effective date of a Change in Control or (ii) whose Continuous Status as an Employee, Director or Consultant is terminated by the Company within the sixty (60) day period immediately preceding the effective date of a Change in Control other than (A) for Cause or (B) upon such person's death or Disability, any Stock Awards held by such person shall: (a) become fully vested, and any repurchase right held by the Company with respect to shares acquired by such person under a Stock Award shall lapse, immediately upon the effective date of such Change in Control, (b) in the event such Stock Award is granted after May 28, 1998 or has an exercise price in excess of $7.50 per share (as adjusted for stock splits and the like subsequent to May 28, 1998) be exercisable within the period ending on the earlier of (u)twelve (12) months following termination of such person's Continuous Status as an Employee, Director or Consultant or (v) expiration of the term of such Stock Award, as set forth therein or as otherwise provided in the Plan and (c)terminate immediately upon the completion of the period described in clause (b)of this sentence, if applicable, or as provided in such Stock Award. (d) Further, with respect to any person (i) who was providing services as an Employee, Director or Consultant immediately prior to the effective date of a Change in Control and (ii) (A) who is Constructively Terminated within the thirteen (13) month period following the effective date of such Change in Control or (B) whose Continuous Status as an Employee, Director or Consultant is terminated by the surviving or acquiring corporation within the thirteen (13) month period following the effective date of such Change in Control other than (w) for Cause or (x) upon such person's death or Disability, any Surviving Stock Awards held by such person shall: (a) become fully vested, and any repurchase right held by the acquiring or surviving corporation with respect to shares acquired by such 16 person under a Surviving Stock Award shall lapse, immediately upon termination of such person's Continuous Status as an Employee, Director or Consultant, (b) in the event such Stock Award is granted after May 28, 1998 or has an exercise price in excess of $7.50 per share (as adjusted for stock splits and the like subsequent to May 28, 1998) be exercisable within the period ending on the earlier of (y) twelve (12) months following termination of such person's Continuous Status as an Employee, Director or Consultant or (z) expiration of the term of such Surviving Stock Award, as set forth therein or as otherwise provided in the Plan and (c) terminate immediately upon completion of the period described in clause (b) of this sentence, if applicable, or as provided in such Stock Award. (e) Notwithstanding subsections 13(c) and (d) above, in the event all of the following occurs: (i) a contemplated Change in Control would occur prior to May 28, 2000 (the date two (2) years following the adoption of subsections 13(c) through (h)); (ii) such potential acceleration of vesting (and exercisability) under subsections 13(c) or (d) would by itself cause a contemplated Change in Control, that would otherwise be eligible to be accounted for as a "pooling of interests" accounting transaction, to become ineligible for such accounting treatment; and (iii) the potential acquiror of the Company desires to account for such contemplated Change in Control as a "pooling of interests" transaction, then such acceleration shall not occur. Additionally, in the event that the restrictions upon acceleration provided for in the immediately preceding sentence by itself would cause a contemplated Change in Control to become ineligible to be accounted for as a "pooling of interests" accounting transaction, then such restrictions shall be deemed inoperative. Accounting issues shall be determined by the Company's independent public accountants applying generally accepted accounting principles. (f) The terms of a particular Stock Award may provide for different terms to govern events described in this Section 13. In the event the provisions of this Section 13 conflict with an employment agreement or other agreement relating to the rights of the holder of a Stock Award, the provisions of this Section 13 and the conflicting agreement shall be construed to provide the greatest benefit to the holder of the Stock Award. 14. AMENDMENT OF THE PLAN AND STOCK AWARDS. (a) The Board at any time, and from time to time, may amend the Plan. However, except as provided in Section 13 relating to adjustments upon changes in stock, no amendment shall be effective unless approved by the stockholders of the Company within twelve (12) months before or after the adoption of the amendment, where the amendment will: (i) Increase the number of shares reserved for Stock Awards under the Plan; (ii) Modify the requirements as to eligibility for participation in the Plan (to the extent such modification requires stockholder approval in order for the Plan to satisfy the requirements of Section 422 of the Code); or (iii) Modify the Plan in any other way if such modification 17 requires stockholder approval in order for the Plan to satisfy the requirements of Section 422 of the Code or to comply with the requirements of Rule 16b-3. (b) The Board may in its sole discretion submit any other amendment to the Plan for stockholder approval, including, but not limited to, amendments to the Plan intended to satisfy the requirements of Section 162(m) of the Code and the regulations promulgated thereunder regarding the exclusion of performance-based compensation from the limit on corporate deductibility of compensation paid to certain executive officers. (c) It is expressly contemplated that the Board may amend the Plan in any respect the Board deems necessary or advisable to provide eligible Employees with the maximum benefits provided or to be provided under the provisions of the Code and the regulations promulgated thereunder relating to Incentive Stock Options and/or to bring the Plan and/or Incentive Stock Options granted under it into compliance therewith. (d) Rights and obligations under any Stock Award granted before amendment of the Plan shall not be impaired by any amendment of the Plan unless (i) the Company requests the consent of the person to whom the Stock Award was granted and (ii) such person consents in writing. (e) The Board at any time, and from time to time, may amend the terms of any one or more Stock Award; provided, however, that the rights and obligations under any Stock Award shall not be impaired by any such amendment unless (i) the Company requests the consent of the person to whom the Stock Award was granted and (ii) such person consents in writing. 15. TERMINATION OR SUSPENSION OF THE PLAN. (a) The Board may suspend or terminate the Plan at any time. Unless sooner terminated, the Plan shall terminate on January 22, 2006, which shall be within ten (10) years from the date the Plan is adopted by the Board or approved by the stockholders of the Company, whichever is earlier. No Stock Awards may be granted under the Plan while the Plan is suspended or after it is terminated. (b) Rights and obligations under any Stock Award granted while the Plan is in effect shall not be impaired by suspension or termination of the Plan, except with the written consent of the person to whom the Stock Award was granted. 16. EFFECTIVE DATE OF PLAN. The Plan shall become effective as determined by the Board, but no Stock Awards granted under the Plan shall be exercised unless and until the Plan has been approved by the stockholders of the Company, which approval shall be within twelve (12) months before or after the date the Plan is adopted by the Board, and, if required, an appropriate permit has been issued by the Commissioner of Corporations of the State of California. 18