The best chat for open source projects

Engage your community with fun, thoughtful, and organized discussion

The Zulip core developers have decades of combined experience writing and maintaining free and open source software. We use Zulip to keep contributors engaged, efficiently make decisions, and fashion the day-to-day experience of being a part of our project. No other chat product comes close to Zulip in facilitating contributor engagement, making efficient use of maintainers' time, and upholding the values of the FOSS community.

If you haven't read why Zulip, read that first. We've also collected a list of features we think will be of particular interest for open source communities using Zulip.

Free hosting at

No catch; the hosting is supported by (and is identical to)'s commercial offerings. This offer extends to any community involved in supporting free and open source software: development projects, foundations, meetups, hackathons, conference committees, and more. If you’re not sure whether your organization qualifies, send us an email at

Scale to thousands of users

For those running Zulip at home, we’ve done a lot of work to ensure that drive-by members of the community don’t consume too many disk or CPU resources. A Zulip server with 1000 active members and 10000 inactive members takes about as many resources as a Zulip server with 1000 active members.

Join without an invitation

Allow anyone to join without an invitation. You can also link to your Zulip with a badge in your readme document.

Authenticate with GitHub

Allow (or require) users to authenticate with their GitHub account, instead of with their email address.

Quality data export

Our high quality export and import tools ensure you can always move from hosting to your own servers.

Syntax highlighting

Full Markdown support, including syntax highlighting, makes it easy to discuss code, paste an error message, or explain a complicated point. Full LaTeX support as well.

Permalink to Zulip conversations from your issue tracker. Zulip’s topic-based threading keeps conversations coherent and organized.

Efficiently refer to issues or code reviews with notation like #1234 or T1234. You can set up any regex as a custom linkification filter for your organization.

Enforce a code of conduct

Link to your community norms or give other instructions right on your Zulip registration page. Admins can delete messages and deactivate (ban) users at any time.

Hundreds of integrations

Get events from GitHub, Travis CI, JIRA, and hundreds of other tools right in Zulip. Topics give each issue its own place for discussion.

Free and open source

Don’t like something? You can open an issue, submit a patch, fork the project, or chat with us directly at All code, including the desktop and mobile apps, is under the Apache 2 license.

Proven model

Check out to see Zulip in action for a project with ~5000 messages of developer discussion a week. The Zulip project is the largest and fastest-growing open source group chat product, both by number of contributors (300+) and by commit velocity (more than Docker and Django combined).

Public archive (coming soon)

Allow search engines to index your chat, with a read-only view of your public streams. Zulip’s topic-based threading keeps conversations coherent and organized, enabling a meaningful archive.