OpenSourceProjects

Open Source Slack Alternatives

Discover 27 open source alternatives to Slack. All free, community-driven, and actively maintained.

What is Slack?

Slack is a messaging platform for team communication and collaboration with channels, direct messages, and integrations.

awesome-selfhosted

awesome-selfhosted

A list of Free Software network services and web applications which can be hosted on your own servers

Rocket.Chat

Rocket.Chat

The Secure CommsOS™ for mission-critical operations

mattermost

mattermost

Mattermost is an open source platform for secure collaboration across the entire software development lifecycle..

platform

platform

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

zulip

zulip

Zulip server and web application. Open-source team chat that helps teams stay productive and focused.

hubot

hubot

A customizable life embetterment robot.

open-im-server

open-im-server

IM Chat OpenClaw

server

server

A simple server for sending and receiving messages in real-time per WebSocket. (Includes a sleek web-ui)

chat

chat

Instant messaging platform. Backend in Go. Clients: Swift iOS, Java Android, JS webapp, scriptable command line; chatbots

Chat Application

element-web

element-web

A glossy Matrix collaboration client for the web.

humhub

humhub

HumHub is an Open Source Enterprise Social Network. Easy to install, intuitive to use and extendable with countless freely available modules.

Enterprise Social Network

ejabberd

ejabberd

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

thelounge

thelounge

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

colanode

colanode

Open-source and local-first Slack and Notion alternative that puts you in control of your data

Chat Application

synapse

synapse

Synapse: Matrix homeserver written in Python/Twisted + Rust

tailchat

tailchat

Next generation noIM application in your own workspace, not only another Slack/Discord/Rocket.chat

Instant Messaging

weechat

weechat

The extensible chat client.

converse.js

converse.js

Web-based XMPP/Jabber chat written in JavaScript

Openfire

Openfire

An XMPP server licensed under the Open Source Apache License.

loomio

loomio

Loomio is a collaborative decision making tool

Collaborative Decision Making

self-hosted

self-hosted

Deploy Stoat on your own infrastructure!

movim

movim

Movim - Decentralized social platform

RetroShare

RetroShare

RetroShare is a Free and Open Source cross-platform, Friend-2-Friend and secure decentralised communication platform.

tuwunel

tuwunel

Official successor to conduwuit

talkyard

talkyard

A community discussion platform: Brings together the main features from StackOverflow, Slack, Discourse, Reddit, and Disqus blog comments.

MongooseIM

MongooseIM

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.

kiwiirc

kiwiirc

🥝 Next generation of the Kiwi IRC web client