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
Matrix reference homeserver
Browse on Tor/i2p, Anon p2p Chat / FileTx, Conf / Video VoIP
Modern, AI-Smart, WASTE p2p for ipv4, Tor and i2p + Voice Conference.
OpenSource Call Center and Dialer System
http://www.vaakpbx.com
A suite of open-source tools and frameworks for creating SIP apps
Baresip is a modular SIP User-Agent with audio and video support
Java VoIP Softphone (SIP) (replaced by jfPhone)
SIP Video Multiconference Media Server with WebRTC support.
H.323 Gatekeeper for VoIP and videconferencing
For more VoIP resources for business, take a look at the business VoIP category.