Kelpie is a SIP to XMPP gateway latest source can be found at http://code.google.com/p/kelpie/ It attempts to make sip endpoints appear as xmpp endpoints and vice-versa The gateway only focuses on protocol translation, a SIP proxy (such as Kamailio) and a federated xmpp server are required for routing. XMPP->SIP This is the easiest case, the xmpp client adds user@{kelpie.hostname} to his contact list, this gets translated as user@{outbound.siproxy} and the proxy routes the messages SIP->XMPP This direction is more complicated. The sip proxy should identify that user is actually an xmpp endpoint and forwards to the kelpie gateway. Kelpie has a mapping of "user" to xmpp ids in its properties file, if it is found it forwards the message to the specified xmpp server. example: com.voxbone.kelpie.mapping.user=user@jabber.org would map sent to sip:user@{kelpie.hostname} to user@jabber.org if you don't want to use the mapping file, the format sip:user+xmpp-server@{kelpie.hostname} can also be used instead note: gtalk doesn't accept calls from bare JIDs, in order to sucessfully call gtalk users, you must define a mapping