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
Browse on Tor/i2p, Anon p2p Chat / FileTx, Conf / Video VoIP
Matrix reference homeserver
Java wrapper for the popular chat & VOIP service
http://www.vaakpbx.com
High performance, production quality STUN server and client library
Open source Fax server software for inbound / outbound internet Faxing
OpenSource Call Center and Dialer System
Java VoIP Softphone (SIP) (replaced by jfPhone)
Modern, AI-Smart, WASTE p2p for ipv4, Tor and i2p + Voice Conference.
Positional Audio Communication for Minecraft with Mumble
For more VoIP resources for business, take a look at the business VoIP category.