JOINT FILING AGREEMENT
In accordance with Rule 13d-1(k)(1)(iii) under the Securities
Exchange Act of 1934, as amended, the persons named below agree to the joint
filing on behalf of each of them of a Statement on Schedule 13D dated May 4,
2006 (including amendments thereto) with respect to the Common Stock of S1
Corporation. This Joint Filing Agreement shall be filed as an Exhibit to such
Statement.
Dated: May 4, 2006
STARBOARD VALUE AND RAMIUS MASTER FUND, LTD
OPPORTUNITY MASTER FUND LTD. By: Ramius Advisors, LLC
its investment manager
PARCHE, LLC By: Ramius Capital Group, L.L.C.
By: Admiral Advisors, LLC, its managing member
its managing member
ADMIRAL ADVISORS, LLC
RCG XXXXXXX MASTER FUND, LTD. By: Ramius Capital Group, L.L.C.,
By: Ramius Capital Group, L.L.C., its managing member
its investment manager
By: C4S & Co., L.L.C., RAMIUS ADVISORS, LLC
its managing member By: Ramius Capital Group, L.L.C.,
its managing member
RCG HALIFAX FUND, LTD.
By: Ramius Capital Group, L.L.C., RAMIUS CAPITAL GROUP, L.L.C.
its investment manager By: C4S & Co., L.L.C.,
By: C4S & Co., L.L.C., as managing member
its managing member
C4S & CO., L.L.C.
RAMIUS FUND III, LTD
By: Ramius Advisors, LLC
its investment manager
By: Ramius Capital Group, LLC
its managing member
By: /s/ Xxxxxx X. Xxxxx
--------------------------
Name: Xxxxxx X. Xxxxx
Title: Authorized Signatory
/s/ Xxxxxx X. Xxxxx
-------------------------------
XXXXXX X. XXXXX
Individually and as attorney-in-fact for Xxxxx X.
Xxxxx, Xxxxxxx X. Xxxxxxx and Xxxxxx X. Xxxxxxx
XXXXXXXXX COMPANIES EQUITY PARTNERS, L.P.
By: Barington Companies Investors, LLC,
its general partner
By: /s/ Xxxxx X. Xxxxxxxxxxx
----------------------------
Name: Xxxxx X. Xxxxxxxxxxx
Title: Managing Member
BARINGTON COMPANIES INVESTORS, LLC
By: /s/ Xxxxx X. Xxxxxxxxxxx
----------------------------
Name: Xxxxx X. Xxxxxxxxxxx
Title: Managing Member
/s/ Xxxxx X. Xxxxxxxxxxx
--------------------------------
Xxxxx X. Xxxxxxxxxxx
BARINGTON COMPANIES OFFSHORE FUND, LTD. (BVI)
By: /s/ Xxxxx X. Xxxxxxxxxxx
----------------------------
Name: Xxxxx X. Xxxxxxxxxxx
Title: President
BARINGTON INVESTMENTS, L.P.
By: Barington Companies Advisors, LLC,
its general partner
By: /s/ Xxxxx X. Xxxxxxxxxxx
----------------------------
Name: Xxxxx X. Xxxxxxxxxxx
Title: Authorized Signatory
BARINGTON COMPANIES ADVISORS, LLC
By: /s/ Xxxxx X. Xxxxxxxxxxx
----------------------------
Name: Xxxxx X. Xxxxxxxxxxx
Title: Authorized Signatory
BARINGTON CAPITAL GROUP, L.P.
By: LNA Capital Corp.,
its general partner
By: /s/ Xxxxx X. Xxxxxxxxxxx
----------------------------
Name: Xxxxx X. Xxxxxxxxxxx
Title: President and Chief Executive Officer
LNA CAPITAL CORP.
By: /s/ Xxxxx X. Xxxxxxxxxxx
----------------------------
Name: Xxxxx X. Xxxxxxxxxxx
Title: President and Chief Executive Officer
/s/ Xxxxxxx X. Xxxxx
--------------------------------
Xxxxxxx X. Xxxxx
