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
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
Matrix reference homeserver
http://www.vaakpbx.com
Java wrapper for the popular chat & VOIP service
OpenSource Call Center and Dialer System
Java VoIP Softphone (SIP) (replaced by jfPhone)
High performance, production quality STUN server and client library
H.323 Gatekeeper for VoIP and videconferencing
Open source Fax server software for inbound / outbound internet Faxing
Positional Audio Communication for Minecraft with Mumble
Baresip is a modular SIP User-Agent with audio and video support
For more VoIP resources for business, take a look at the business VoIP category.
