Java VoIP Softphone (SIP) (replaced by jfPhone)
Accent interfaces and controls systems through goals and policies
SIP Video Multiconference Media Server with WebRTC support.
Java VoIP/SIP PBX system (replaced by jfPBX)
Open source streamlined SIP client built on Linphone
A suite of open-source tools and frameworks for creating SIP apps
C++ SIP stack based on Chrome source code