Janus

Janus is an open‑source WebRTC server that provides the core signaling and media relay needed for real‑time communication between browsers and server‑side applications. It establishes WebRTC sessions, exchanges JSON messages, and forwards RTP/RTCP streams, while leaving application‑specific behavior to modular plugins such as echo tests, conference bridges, media recorders, or SIP gateways. The server is written in C for a small footprint and can be deployed on Linux or macOS, with optional support for Windows Subsystem for Linux.

The design targets developers and operators who need a lightweight, self‑hosted gateway that can be extended through pluggable modules. By exposing a generic API, Janus lets custom server logic interact with WebRTC media without embedding any particular feature set, making it suitable for cloud‑scale deployments as well as embedded devices. Its plugin architecture allows users to enable only the functionality they require, keeping resource usage minimal.

Janus is released under GPL‑3.0, is maintained as a stable, free‑tier project, and relies on common libraries such as GLib, OpenSSL, libnice, and libsrtp. Optional dependencies enable additional capabilities like Data Channels, REST or WebSocket APIs, and integration with messaging systems (MQTT, RabbitMQ, Nanomsg). Documentation, demos, and a community forum are available for setup and troubleshooting.