Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. XML Interface to Messaging, Scheduling, and Signaling ("XIMSS") is an XML-based API for IP Communications. The XIMSS API was introduced by CommuniGate Systems in their CommuniGate Pro (often referred to as "CGP") server starting with version 5.1 in Summer 2006. Their announcement described XIMSS as being based on the "open, proposed standard XIMSS, based on previous XML RFCs" but it is not clear whether there is any formal proposal defining XIMSS before any standards body, and CommuniGate does not explicitly specify which RFC''s they were referring to as a basis for XIMSS. The only server implementation of XIMSS is CommuniGate Pro, and there are few applications publicly available using XIMSS other than CommuniGate''s Flash-based "Pronto" integrated messaging client.