VoIP SIP and SKINNY quality analyzer and packet / audio recording tool
Open source Fax server software for inbound / outbound internet Faxing
Issabel PBX - Unified Communications
Unified Communications Server
Java VoIP Softphone (SIP) (replaced by jfPhone)
Free software and hardware for telephony
High performance, production quality STUN server and client library
SIP softphone
H.323 Gatekeeper for VoIP and videconferencing
SIP Video Multiconference Media Server with WebRTC support.
A command line utility for remote controlling Polycom VVX IP phones
An administration web interface for Mumble VoIP servers in PHP
VozBox. Asterisk VoIP PBX.
Positional Audio Communication for Minecraft with Mumble
Cyber-wrt pbx is embedded system in DD-Wrt router