A suite of open-source tools and frameworks for creating SIP apps
Free, native Windows SIP softphone with HD audio, SRTP encryption
H.323 Gatekeeper for VoIP and videconferencing
VoIP/SIP Autodialer
SIP softphone
Baresip is a modular SIP User-Agent with audio and video support
An administration web interface for Mumble VoIP servers in PHP
client-server full java chat audio-video file sharing
vTiger Freeswitch PBX Integration
OpenSource Call Center and Dialer System
ERP, IP PBX, Accounting, CRM, Time tracking, and etc.
Respins of various open source PBX projects