Java wrapper for the popular chat & VOIP service
Issabel PBX - Unified Communications
Free, native Windows SIP softphone with HD audio, SRTP encryption
Desktop communication tool: chat, telephony, multimedia
ICTCore: Unified Communications Framework for web developers
A WebRTC-Enabled Chrome Extension for Seamless Call Center
The most affordable CRM system according to Capterra
A beautiful SMS messenger for Android
Java VoIP Softphone (SIP) (replaced by jfPhone)
High performance, production quality STUN server and client library
Asterisk based VoIP pbx appliance
Accent interfaces and controls systems through goals and policies
Blocks unwanted calls using caller ID and a modem
Enterprise telephony recording and retrieval system
H.323 Gatekeeper for VoIP and videconferencing
SE-7100 Series HEVC Encoder
SIP Video Multiconference Media Server with WebRTC support.
Cress is a comprehensive toolset for graphical service/workflow design
Java VoIP/SIP PBX system (replaced by jfPBX)
Positional Audio Communication for Minecraft with Mumble