Open-source team chat

6 team chat whose code is public under an OSI-approved license, rated for privacy with evidence. Picks first, then by score.

1. Campfire Grade B

   Self-hosted group chat web app from 37signals with rooms, direct messages, file attachments, search and bot integrations, distributed through ONCE.

   MIT. Source code

2. Xeres Grade B

   A decentralized, encrypted P2P friend-to-friend app for chat, forums, channels, boards, voice calls and anonymous file sharing.

   GPL-3.0. Source code

3. Nextcloud Talk Grade C

   Chat, audio and video call app for Nextcloud servers, with group conversations, screen sharing, desktop and mobile clients, and optional federation between servers.

   Server app and clients are AGPL-3.0 or GPL-3.0. Source code

4. Stoat Grade C

   Open source chat platform for friends and communities with servers, channels, direct messages and voice chat, formerly named Revolt. The server software can be self-hosted.

   Server and apps are AGPL-3.0. Source code

5. Zulip Grade C

   Open source team chat that organizes conversations into channels and named topics. It can be self-hosted or used as the Zulip Cloud service run by Kandra Labs.

   Apache-2.0. Source code

6. Element Grade C

   Matrix client for web, desktop and mobile with end-to-end encrypted chats, group rooms, file sharing and voice and video calls. Built by Element, which also sells hosted and self-hosted Matrix servers.

   AGPL-3.0 and GPL-3.0. Source code

Compare all 11 team chat, open source or not.