MongooseIM

MongooseIM is an XMPP‑based instant messaging server designed for large‑scale, enterprise deployments. It runs on clustered Erlang nodes, providing fault tolerance and the ability to increase capacity simply by adding additional machines or virtual instances. The server accepts client connections via standard XMPP, REST API, Server‑Sent Events, WebSockets, and BOSH, and includes built‑in components for testing, metrics, load testing, and monitoring.

The platform targets organizations that need a self‑hosted, open‑source solution with high performance and scalability. It is released under GPL‑2.0 and offers a free tier without subscription requirements, making it suitable for teams that want full control over their messaging infrastructure while leveraging community‑driven client libraries for XMPP and REST.

Distinctive aspects include its modular architecture that separates backend and frontend services, extensive documentation, and ready‑to‑use deployment options such as Docker images, Helm charts, and pre‑built packages for major Linux distributions. The project is actively maintained, with continuous integration testing and code‑coverage reporting to ensure stability.