Browse free open source VoIP software and projects below. Use the toggles on the left to filter open source VoIP software by OS, license, language, programming language, and project status.
Issabel PBX - Unified Communications
VoIP SIP and SKINNY quality analyzer and packet / audio recording tool
Matrix reference homeserver
Unified Communications Server
A simple noise gate app intended for use with VOIPs like Skype.
Browse on Tor / i2p - Anon p2p Chat / FileTx, Conf / Video VoIP
Java wrapper for the popular chat & VOIP service
H.323 Gatekeeper for VoIP and videconferencing
http://www.vaakpbx.com
OpenSource Call Center and Dialer System
Free, native Windows SIP softphone with HD audio, SRTP encryption
Phone and SMS app with free, encrypted calls between ARK-phone users
Respins of various open source PBX projects