XML-RPC: UserLand Software, 1998 (Dave Winer, Don Box) SOAP 1.0: Microsoft, 1999 SOAP 1.1: Don Box, DevelopMentor; IBM; Microsoft; 2000 SOAP 1.2: W3C, very soon now... Changes from 1.1 to 1.2 SOAP is no longer an acronym Specs split into three logical parts (Intro, Core, Add-ins) Based on XML Infoset rather than XML 1.0 Namespaces changed to differenticate from 1.1 - XML Infoset spec]]>