Matrix reference homeserver
VoIP SIP and SKINNY quality analyzer and packet / audio recording tool
Open source Fax server software for inbound / outbound internet Faxing
VICIdial call center optimization tools, monitoring utilities, and per
Unified Communications Server
Kazoo Live Medium. From Null to a Full Featured PBX on minutes
Accent interfaces and controls systems through goals and policies
SIP Video Multiconference Media Server with WebRTC support.
CMS API Server with web site
A Murmur-Server Webinterface written in PHP for Mumble
A suite of open-source tools and frameworks for creating SIP apps