VoIP SIP and SKINNY quality analyzer and packet / audio recording tool
Unified Communications Server
Project about FusionPBX on Live Medium
High performance, production quality STUN server and client library
VoIP/SIP Autodialer
H.323 Gatekeeper for VoIP and videconferencing
SIP softphone
Callflow Sequence Diagram Generator
A command line utility for remote controlling Polycom VVX IP phones
Simple web interface for mapping CDR from VoIP provider to Asterisk
Java VoIP/SIP PBX system (replaced by jfPBX)
An administration web interface for Mumble VoIP servers in PHP
Simple and efficient tool for SIP trace filtering