18 self-hosted Mattermost Cloud alternatives

Rocket.Chat is an open-source communications platform for secure team messaging, channels, DMs, voice/video, integrations, and customer omnichannel support.

46k stars13.8k forkslast commit 27 Aug 2026Actively maintained

Open-source team chat server with topic-based threading for focused, asynchronous, and real-time communication in distributed teams.

25.8k stars10.1k forksApache-2.0last commit 25 Aug 2026Actively maintained

Element is a Matrix client for secure team messaging and collaboration, offering end-to-end encrypted chats and calls with interoperability across the Matrix network.

13.4k stars2.7k forksAGPL-3.0last commit 26 Aug 2026Actively maintained

Spacebar is an open source, self-hostable Discord-compatible communication platform with text chat, voice, and video, designed to work with existing clients and bots.

6.7k stars222 forksAGPL-3.0last commit 9 Apr 2026Actively maintained

Synapse is a Matrix homeserver implementation for running federated, secure real-time chat and collaboration on your own infrastructure.

4.6k stars587 forksAGPL-3.0last commit 26 Aug 2026Actively maintained

Tailchat is an open source team chat and collaboration platform with a strong plugin system, bot integrations, multi-group workspaces, and RBAC permissions.

3.6k stars397 forksApache-2.0last commit 22 Aug 2026Actively maintained

Ergo is a modern IRC server (ircd) written in Go, with integrated account management, history storage, bouncer-like features, and strong IRCv3 support.

3.3k stars242 forksMITlast commit 27 Aug 2026Actively maintained

Converse.js is an open-source, client-side web XMPP/Jabber chat app that can run standalone or be embedded into sites, with group chat and OMEMO encryption.

3.3k stars832 forksMPL-2.0last commit 14 Aug 2026Actively maintained

Stoat is an open-source, self-hostable chat platform for communities and teams, offering text channels, permissions, moderation tools, and a web app.

3.3k stars383 forkslast commit 27 Aug 2026Actively maintained

Openfire is an open source XMPP (Jabber) server for real-time messaging and collaboration, with a web admin console and a plugin ecosystem.

3.1k stars1.4k forksApache-2.0last commit 25 Aug 2026Actively maintained

Stoat (formerly Revolt) is an open-source chat platform for communities and teams with channels, direct messages, roles/permissions, moderation tools, and bot support.

2.6k stars296 forksAGPL-3.0last commit 14 Aug 2026Actively maintained

Movim is a federated social platform and web-based XMPP client for blogging, chat, communities, and real-time messaging with a responsive cross‑platform interface.

2k stars281 forksAGPL-3.0last commit 26 Aug 2026Actively maintained

Self-hostable community discussion platform combining Q&A, forums, team chat, ideation/upvoting, and Disqus-style embedded blog comments.

1.8k stars129 forksAGPL-3.0last commit 10 Jul 2026Actively maintained

SAMA is a Node.js-based open-source chat server using uWebSockets.js, MongoDB and Redis, providing WebSocket/HTTP APIs, E2EE, clustering, and web/mobile clients.

158 stars15 forksGPL-3.0last commit 22 Jul 2026Actively maintained

Libervia is a modular XMPP-based communication suite offering chat, microblogging, file sharing, and other social features across web, desktop, and CLI interfaces.

Activity unknown

Salut à Toi (SàT) is a self-hostable, XMPP-based communication suite with web, desktop, and CLI frontends, supporting chat and collaborative features via plugins.

Activity unknown

A single-binary, low-resource Matrix homeserver in Rust; simple setup, RocksDB (default) or SQLite backends, built with axum and Ruma.

Activity unknown

Prosody IM is a modern, resource-efficient XMPP (Jabber) server written in Lua, designed to be easy to configure and extend for private messaging and federation.

Activity unknown