VoIP/SIP SoftPhone (formerly known as jphonelite)
Unified Communications Server
test file
Java VoIP Softphone (SIP) (replaced by jfPhone)
Low-latency, high quality voice chat for gamers
Online Internet Phone Call Center Software For Telesales Team
H.323 Gatekeeper for VoIP and videconferencing
TEKSTER is a Computer Application To Send FREE SMS Around the World!
a voip billing system for the raspberry pi
A suite of open-source tools and frameworks for creating SIP apps