cat-team-chat

fast & lightweight self-hosted messenger

Unofficial open source mtproto server written in golang with compatible telegram client.

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

MongooseIM is Erlang Solutions' robust, scalable and efficient XMPP server, aimed at large installations. Specifically designed for enterprise purposes, it is fault-tolerant and can utilise the resources of multiple clustered machines.

A collaborative web application (virtual office) presented as a 16-bit RPG video game

Huly — All-in-One Project Management Platform (alternative to Linear, Jira, Slack, Notion, Motion)

bridge between mattermost, IRC, gitter, xmpp, slack, discord, telegram, rocketchat, twitch, ssh-chat, zulip, whatsapp, keybase, matrix, microsoft teams, nextcloud, mumble, vk and more with REST API (mattermost not required!)

Mumble is an open-source, low-latency, high quality voice chat software.

A glossy Matrix collaboration client for the web.

An XMPP server licensed under the Open Source Apache License.

A high-performance Internet Relay Chat (IRCv3) server for UNIX-like and Windows systems

Official successor to conduwuit

The Secure CommsOS™ for mission-critical operations

An AI chat bot for small and medium-sized teams, supporting models such as Deepseek, Open AI, Claude, and Gemini. 专为中小团队设计的 AI 聊天应用，支持 Deepseek、Open AI、Claude、Gemini 等模型。

💬 ‎ Modern, responsive, cross-platform, self-hosted web IRC client

Secure peer-to-peer chat that is serverless, decentralized, and ephemeral

Macro is a unified workspace for teams: email, chat, docs, tasks, agents, calls, and CRM — @-linked together with shared AI memory.

Synapse: Matrix homeserver written in Python/Twisted + Rust

A modern IRC server (daemon/ircd) written in Go.

Deploy Stoat on your own infrastructure!