Sofia-SIP library glib/gobject interface development files Sofia-SIP is an open-source SIP User-Agent library, compliant with the IETF RFC3261 specification. It can be used as a building block for SIP client software for uses such as VoIP, IM, and many other real-time and person-to-person communication services. This package provides the headers and libraries needed to build applications against the glib/object interfaces of Sofia-SIP library.