VoIP SIP and SKINNY quality analyzer and packet / audio recording tool
VICIdial Contact Center Suite
High performance, production quality STUN server and client library
Multi user address book application accessable through the web.
A command line utility for remote controlling Polycom VVX IP phones
A simple noise gate app intended for use with VOIPs like Skype.
Asterisk and Yate (VoIP PBX) Scripts and Libraries
A suite of open-source tools and frameworks for creating SIP apps
The Agispeedy is an AGI Application Server implemention in asterisk