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
A simple noise gate app intended for use with VOIPs like Skype.
Unified Communications Server
Java wrapper for the popular chat & VOIP service
Browse on Tor / i2p - Anon p2p Chat / FileTx, Conf / Video VoIP
http://www.vaakpbx.com
Matrix reference homeserver
Java VoIP Softphone (SIP) (replaced by jfPhone)
Respins of various open source PBX projects
Positional Audio Communication for Minecraft with Mumble
Open source Fax server software for inbound / outbound internet Faxing
Free, native Windows SIP softphone with HD audio, SRTP encryption
An administration web interface for Mumble VoIP servers in PHP