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Exhibit 10.1
  
 Transition Agreement
  1.
 2. Expiration of Employment Agreement.
 3. Severance Payments upon Termination of Employment.
 4. Transition Period and Additional Severance Payments and Benefits.




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Mr. E. Wayne Jackson, III
February 27, 2008
Page 2 of 9
  5. Employment Status during Transition Period. provided however,
 6. Definition of Cause.
 7. Accrued Salary and Vacation.




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Mr. E. Wayne Jackson, III
February 27, 2008
Page 3 of 9
 8. Benefit Plans.
    9. Equity Awards.




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Mr. E. Wayne Jackson, III
February 27, 2008
Page 4 of 9
  10. Other Compensation or Benefits/Resignation by You.
 11. Expense Reimbursements.
 12. Return of Company Property. Receipt of the Severance described in this
Agreement is expressly conditioned upon return of all Company Property.
 13. Proprietary Information Obligations.
 14. Confidentiality.




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Mr. E. Wayne Jackson, III
February 27, 2008
Page 5 of 9
  15. Non-Disparagement.
 16. Cooperation after Termination.
 17. Release.




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Mr. E. Wayne Jackson, III
February 27, 2008
Page 6 of 9
 
    
    has violated its personnel policies, handbooks, contracts of employment, or
covenants of good faith and fair dealing;
    
    has discriminated against you on the basis of age, race, color, sex (including
sexual harassment), national origin, ancestry, disability, religion, sexual
orientation, marital status, parental status, source of income, entitlement to
benefits, any union activities or other protected category in violation of any local,
state or federal law, constitution, ordinance, or regulation, including but not limited
to: Title VII of the Civil Rights Act of 1964, as amended; 42 U.S.C. § 1981, as
amended; the Equal Pay Act; the Americans With Disabilities Act; the Family Medical
Leave Act; the Maryland Human Relations Commission Act; the Employee Retirement Income
Security Act; Section 510; and the National Labor Relations Act;
    
    has violated any statute, public policy or common law (including but not
limited to claims for retaliatory discharge; negligent hiring, retention or
supervision; defamation; intentional or negligent infliction of emotional distress
and/or mental anguish; intentional interference with contract; negligence; detrimental
reliance; loss of consortium to you or any member of your family and/or promissory
estoppel).




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Mr. E. Wayne Jackson, III
February 27, 2008
Page 7 of 9
 18. Indemnification Rights.
 19. No Admission.
 20. Breach.
 21. Miscellaneous.




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Mr. E. Wayne Jackson, III
February 27, 2008
Page 8 of 9




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Mr. E. Wayne Jackson, III
February 27, 2008
Page 9 of 9
   Sincerely,Sourcefire, Inc.By:
    
    /s/ Joseph R. ChinniciJoseph Chinnici, Chairman
 Agreed to and Accepted:
 /s/
E. Wayne Jackson, IIIE. Wayne Jackson, III
 Consideration Period
  /s/  E.
Wayne Jackson, III
    
    February 27, 2008Signature
    
    Date




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Exhibit A
CERTIFICATE AND RELEASE OF CLAIMS
     E. Wayne Jackson, IIIDated:




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Exhibit B
Resignation Letter
   Sincerely yours,E. Wayne Jackson, IIIDated:




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Exhibit C
 Amended and Restated Assignment of Inventions, Non-Disclosure, Non-Solicitation and Non-Competition
Agreement