Open-source team chat with topic-based threading for live and async work. Paid Zulip Cloud or self-host on Ubuntu, Debian, and Docker.
Zulip is an open source alternative to Slack. Open-source team chat with topic-based threading for live and async work. Paid Zulip Cloud or self-host on Ubuntu, Debian, and Docker. Apache-2.0 licensed, 25.5k GitHub stars, hosted version available, self-host with Docker, no terminal required to start, and last released 2026-06-26.
Should you switch?
Use it if
Teams that want topic-based threading to keep live and asynchronous conversations organized, with the option to self-host on Ubuntu or Debian.
Self-hosting targets Ubuntu or Debian Linux and requires server administration. The Docker image lives in a separate community repo (zulip/docker-zulip) from the main application.
"I've used Zulip. It's a cool idea, though it turned out to be still too beta to replace HipChat at my company. The key feature is having multiple threads of conversation in one room..."
"We used Zulip for some time. Overall it's pretty good - the clients could really need a bit more love though. What I always found amazing was their support."