Open source Communication & Community tools

12 open-source tools in this category.

Showing 7 results in Team Chat

Rocket.Chat

Rocket.Chat

Self-hosted team messaging — channels, video, and compliance.

MIT-licensed alternative to Slack and Mattermost with end-to-end encryption, Omnichannel, apps marketplace, and FedRAMP-ready compliance.

chatmessagingcollaboration
45.4K13.6KMIT
vs Slack
Mattermost

Mattermost

Secure team collaboration — messaging, playbooks, and integrations.

MIT-licensed alternative to Slack with channels, threads, webhooks, Jira/GitHub integrations, and Playbooks for incident response. Desktop and mobile apps.

chatcollaborationmessaging
36.9K8.7KMIT
vs Slack
Zulip

Zulip

Topic-threaded team chat — keeps conversations organized at scale.

Zulip is an open-source team chat application built around topic-based threading, which keeps conversations organized in a way that channel-only tools like Slack or Rocket.Chat don't. Apache-2.0 licensed and self-hostable.

chatmessagingcollaboration
25.5K9.9KApache-2.0
vs Slack
Element

Element

Matrix-based team messaging — decentralized and end-to-end encrypted.

Element is an open-source, end-to-end encrypted collaboration client built on the decentralized Matrix protocol, so it can federate across independent servers rather than relying on one company's infrastructure. AGPL-3.0 licensed.

chatmessagingcollaboration
13.3K2.7KAGPL-3.0
vs Slack
Campfire

Campfire

Simple self-hosted group chat from 37signals — one-time, MIT-licensed, no subscription.

Campfire is a simple, self-hosted group chat application from 37signals, released as open source under the MIT license in 2025. It's deliberately minimal — @mentions, DMs, rooms — with no recurring subscription.

chatmessagingcollaboration
4.4K747MIT
vs Slack
Wire

Wire

End-to-end encrypted team collaboration — messaging, calls, EU-based.

Wire is an open-source, end-to-end encrypted collaboration platform for messaging, calls, and file sharing, aimed at organizations with strong security and compliance requirements. AGPL-3.0 licensed, based in the EU.

chatmessagingcollaboration
2.8K333AGPL-3.0
vs Slack
Quiet

Quiet

Peer-to-peer team chat over Tor — no servers, no phone number, no metadata.

Quiet is an open-source, peer-to-peer team chat that syncs messages directly between devices over Tor, with no central server, no phone number, and no metadata collection. GPL-3.0 licensed.

chatmessagingcommunity
2.6K141GPL-3.0
vs Slack