Browse free open source Telephony software and projects below. Use the toggles on the left to filter open source Telephony software by OS, license, language, programming language, and project status.
Unified Communications Server
OpenSource Call Center and Dialer System
A suite of open-source tools and frameworks for creating SIP apps
Java VoIP Softphone (SIP) (replaced by jfPhone)
VoIP/SIP SoftPhone (formerly known as jphonelite)
H.323 Gatekeeper for VoIP and videconferencing