Browse free open source Internet Phone software and projects for Linux below. Use the toggles on the left to filter open source Internet Phone software by OS, license, language, programming language, and project status.
Unified Communications Server
Low-latency, high quality voice chat for gamers
Java VoIP Softphone (SIP) (replaced by jfPhone)
A suite of open-source tools and frameworks for creating SIP apps
H.323 Gatekeeper for VoIP and videconferencing
VoIP/SIP SoftPhone (formerly known as jphonelite)