A domain based multi-tenant PBX & voice switch for FreeSWITCH
VoIP SIP and SKINNY quality analyzer and packet / audio recording tool
Cellular manager for mobile phones/modems
Web based system for Computer Assisted Telephone Interviewing (CATI)
Open source Fax server software for inbound / outbound internet Faxing
The most affordable CRM system according to Capterra
Project about FusionPBX on Live Medium
Enterprise telephony recording and retrieval system
Callflow Sequence Diagram Generator
Cress is a comprehensive toolset for graphical service/workflow design
An administration web interface for Mumble VoIP servers in PHP
Linux GUI USSD Sender
A simple noise gate app intended for use with VOIPs like Skype.
Cyber-wrt pbx is embedded system in DD-Wrt router
Baresip is a modular SIP User-Agent with audio and video support
A suite of open-source tools and frameworks for creating SIP apps