VoIP/SIP SoftPhone (formerly known as jphonelite)
The point is an convenience
Unified Communications Server
Java VoIP Softphone (SIP) (replaced by jfPhone)
Low-latency, high quality voice chat for gamers
H.323 Gatekeeper for VoIP and videconferencing
Chat with your friends everywhere, whether you are in space or on eart
TEKSTER is a Computer Application To Send FREE SMS Around the World!
A suite of open-source tools and frameworks for creating SIP apps