OpenXCAP is an Open Source, easy extensible, fully featured XCAP server with TLS security and support for multiple realms. XCAP protocol allows a client to read, write, and modify application configuration data stored in XML format on a server.
XCAP maps XML document sub-trees and element attributes to HTTP URIs, so that these components can be directly accessed by HTTP. An XCAP server is used by the XCAP clients to store data like Presence policy in combination with a SIP server that supports PUBLISH/SUBSCRIBE/NOTIFY methods to provide a complete SIP SIMPLE server solution.
The XCAP server is used as a policy decision maker by the SIP Presence server to manage the subscriptions and notifications of presence information based on end-user controlled preferences. An immediate advantage of using an XCAP server is to allow end-users to reliably syncronize presence configuration data like buddy lists and access lists between multiple SIP SIMPLE devices. The XCAP server can also be used to publish to SIP devices information retrieved from external sources and using different APIs acting like a bridge between real-time communications based on SIP protocol and other web technologies like SOAP/XML.
The project is hosted at http://openxcap.org