1 Exhibit 21 SUBSIDIARIES Name Jurisdiction of Organization Names under which - - ---- ---------------------------- it Does Business ---------------- S1, Inc. Kentucky S1 S1 Holdings, LLC Delaware S1 Europe Holdings C.V.A. Belgium Edify Corporation Delaware FICS Group N.V. Belgium VerticalOne Corporation Delaware Austin Acquisition Corporation Texas Delta Acquisitions Corporation Delaware Temple Acquisition Corporation Delaware S1 UK Ltd. United Kingdom - 20 -