Employee Stock Purchase Plan

1. Employee Stock Purchase Plan

2. Employee Stock Purchase Plan • Benefits of ESPP - Ability to purchase ACCL stock at discounted rate - Increased “stake” in future success of ACCL - Convenient payroll deductions • Eligibility Criteria - Must be an employee prior to the Purchasing Period start date (date of hire must be no later than 5/31/12)

3. Employee Stock Purchase Plan Plan Mechanics Salary deferrals over two 6 month Purchase Periods comprising one 12 month Offering Period New Offering Period: June 1 through May 31 Purchase Periods: June 1 to November 30 and December 1 to May 31 Purchase Price of Stock - 85% of the lower of the market price close on either the first day or last day of the 1st Purchase Period within a given Offering Period for the 1st Purchase Period within a 12 month Offering Period - 85% of the lower of the market price close at either the first day of the 1st Purchase Period or last day of the 2nd Purchase Period in an Offering Period for the 2nd Purchase Period within a 12 month Offering Period

4. Employee Stock Purchase Plan Purchase Price Example: Initial price as of 1st day of Offering Period 1st Purchase Period Purchase Price Per Share: $5.00 – 15% = $4.25 2nd Purchase Period Purchase Price Per Share: $5.00 – 15% = $4.25

5. Employee Stock Purchase Plan Plan Mechanics (cont.) • Maximum % Salary Deferral & Maximum # of Shares Purchasable 1 - 10% of Salary per Purchase Period 1,000 Shares per Purchase Period • International Conversion Rates At the close of a Purchase Period, non-U$D contributions will be converted to U$D for the purpose of purchasing shares of ACCL stock at the prevailing market exchange rate as of that day • Enrollment Requirements - Enrollment is “evergreen” and continues into future periods - Enrollment forms required for new enrollments and to re-enroll following cancellation of prior plan participation

6. Employee Stock Purchase Plan Plan Mechanics (cont.) Issuance of Shares from Purchase - Shares will be issued in street name and delivered directly to your E*Trade account • Recordkeeping - At least annually, you will receive a statement from Accelrys itemizing your deferral(s), number of shares purchased, and the respective purchase price(s) -Retain these summaries for your records and for future tax basis purposes - In accordance with IRS regulations, annually Accelrys will send out a form to all employees requesting that you report the sale of any ESPP stock

7. Employee Stock Purchase Plan Enrollment Process • All eligible employees may elect to enroll in the ESPP for the new Offering Period by completing online enrollment via E*Trade : www.etrade.com/enroll  • Current Accelrys E*Trade accountholders can use the LOG ON feature to make their plan election. • U.S. employees without an Accelrys E*Trade account can enter the ACCL stock symbol and their social security number to enroll. • Non-U.S. employees without existing Accelrys E*Trade accounts can enter the ACCL stock symbol and their Account ID. Account ID’s can be obtained from Jamie Moxley or your local HR representative.

8. Employee Stock Purchase PlanEnrollment (cont.) • If you are currently enrolled and would like to continue participation with no change to your contribution percentage in the upcoming Offering Period, your participation will continue and there is no action required. • If you are currently enrolled but would like to change your contribution percentage for the upcoming period, please complete the online enrollment on or before May 31st. Due Date: May 31, 2012