PHP version of Google's phone number handling library
Java wrapper for the popular chat & VOIP service
VICIdial Contact Center Suite
Web based system for Computer Assisted Telephone Interviewing (CATI)
Cellular manager for mobile phones/modems
Convert VoIP calls to text and analyze them with AI
Software per Call Center
Unified Communications Server
Unified Communications System - PBX System
Java VoIP Softphone (SIP) (replaced by jfPhone)
AstCDR
Accent interfaces and controls systems through goals and policies
Enterprise telephony recording and retrieval system
H.323 Gatekeeper for VoIP and videconferencing
Cress is a comprehensive toolset for graphical service/workflow design
Java VoIP/SIP PBX system (replaced by jfPBX)
An administration web interface for Mumble VoIP servers in PHP