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Communication

Open source alternatives to Slack

Team chat and collaboration. 5 open source projects replace it, led by Rocket.Chat with 46k GitHub stars. Licenses and stars are read from GitHub.

  1. #1

    Rocket.Chat

    ★ 46k

    Open source team chat with omnichannel support.

    MITLast commit 2026-10-12View on GitHub ↗
  2. #2

    Mattermost

    ★ 39k

    Self-hosted secure team collaboration platform.

    MIT / AGPL-3.0Last commit 2026-10-12View on GitHub ↗
  3. #3

    Huly

    ★ 28k

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

    EPL-2.0Last commit 2026-10-07View on GitHub ↗
  4. #4

    Zulip

    ★ 26k

    Threaded team chat that keeps conversations organized.

    Apache-2.0Last commit 2026-10-12View on GitHub ↗
  5. #5

    Quiet

    ★ 2.7k

    A private, p2p alternative to Slack and Discord built on Tor & IPFS

    GPL-3.0Last commit 2026-09-28View on GitHub ↗

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