Browse free open source VoIP software and projects for Windows 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
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
H.323 Gatekeeper for VoIP and videconferencing
High performance, production quality STUN server and client library
Respins of various open source PBX projects
A command line utility for remote controlling Polycom VVX IP phones
Positional Audio Communication for Minecraft with Mumble
Free, native Windows SIP softphone with HD audio, SRTP encryption
Java VoIP Softphone (SIP) (replaced by jfPhone)
Modern, AI-Smart, WASTE p2p for ipv4, Tor and i2p + Voice Conference.
Convert VoIP calls to text and analyze them with AI
ERP, IP PBX, Accounting, CRM, Time tracking, and etc.
VoIP/SIP Autodialer