Open Source Everything

Team chat

Chat for workplaces and projects.

4open alternatives 4do the whole job

Open alternatives4

Open-source apps that replace Slack and Microsoft Teams

Rocket.Chat screenshot
46kActiveWindows · Mac · Linux · Android · iPhone · In your browserMITOpen coreRuns on your own server

Rocket.Chat is a team messaging platform for real-time chat, voice calls and federation between organizations. It is aimed at workplaces and organizations that want to host their own chat with strong data protection.

Runs on your own server · GitHub
Mattermost screenshot
39kActiveWindows · Mac · Linux · Android · iPhone · In your browserAGPL-3.0Runs on your own server

Mattermost is a team chat platform that you install on your own server, so your company's messages stay under its control. It is aimed at workplaces and IT teams that want chat, workflow automation and voice calls in one place.

Runs on your own server · GitHub
Zulip screenshot
26kActiveWindows · Mac · Linux · Android · iPhone · In your browserApache-2.0Runs on your own server

Zulip is a team chat app where conversations are organized by topic, so it combines features of email and chat. It is for workplaces and open-source projects, and can be used on the web or self-hosted on your own server.

Runs on your own server · GitHub
Element screenshot
14kActiveWindows · Mac · Linux · Android · iPhone · In your browserVerifiedAGPL-3.0App

Element is a chat app for private messages and group chats over the Matrix network, used in a web browser or as a desktop app. It is for people and teams who want chat they can host and control, with phone apps offered as separate Element X projects.

App · GitHub · Chat network (Matrix); some set-up needed

What's missing

What people still miss here, and wish existed. Upvote what matters to you.

Before you build

Planning something for team chat? See what exists first, so you can reuse parts or explain what's different. Paste this into any AI assistant:

Read the list of open-source alternatives at https://opensourceeverything.org/data/groups/team-chat.json. Compare it with my project or idea below. Tell me which projects overlap, what I could reuse instead of rewriting, and what mine does that none of them do. My project or idea:
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Fix the list itself

A project or closed app missing from this list, or a mistake on it? These open a short form on GitHub, and a mod reviews it. To say what a project can't do, use What's missing.

About this page

Replaces fully means it does the main job of these apps; Replaces partly means it covers some of it.

Licenses: every project here uses an open-source license (what each one means). Open core means some parts are paid or under another license.

GitHub stars are shown for reference. They measure popularity, not whether it replaces anything.

Verified means r/TrueOpenSource mods checked it: open-source license, maintained, and it really does the job.

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