Robust, Ubiquitous and Massively Scalable Messaging Platform (XMPP, MQTT, SIP Server)

FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a versatile software implementation that runs on any commodity hardware. From a Raspberry PI to a multi-core server, FreeSWITCH can unlock the telecommunications potential of any device.

WebRTC plugin for Flutter Mobile/Desktop/Web

Jitsi is an audio/video and chat communicator that supports protocols such as SIP, XMPP/Jabber, IRC and many other useful features.

RTSP/RTP/RTMP/FLV/HLS/MPEG-TS/MPEG-PS/MPEG-DASH/MP4/fMP4/MKV/WebM

The official Asterisk Project repository.

Kamailio - The Open Source SIP Server for large VoIP and real-time communication platforms, focusing on flexibility, security and scalability

PJSIP project

A simple, intuitive, and powerful JavaScript signaling library

Baresip is a modular SIP User-Agent with audio and video support

HOMER - 100% Open-Source SIP, VoIP, RTC Packet Capture & Monitoring

A WebRTC, SIP and VoIP library for C# and .NET. Designed for real-time communications apps.

⚡ The future of programmable SIP servers.

Linphone.org mirror for linphone-android (https://gitlab.linphone.org/BC/public/linphone-android)

Ncurses SIP Messages flow viewer

SIP softphone for Mac

SIPVicious OSS is a VoIP security testing toolset. It helps security teams, QA and developers test SIP-based VoIP systems and applications. This toolset is useful in simulating VoIP hacking attacks against PBX systems especially through identification, scanning, extension enumeration and password cracking.

Pluggable WebRTC softphone and communication platform.

A Go implementation of STUN

Rapida is an open-source, end-to-end voice AI orchestration platform for building real-time conversational voice agents with audio streaming, STT, TTS, VAD, multi-channel integration, agent state management, and observability.