The best chat for open source projects

Engage your community with fun, thoughtful, and organized discussion

The uKnowva Messenger core developers have decades of combined experience writing and maintaining free and open source software. We use uKnowva Messenger 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 uKnowva Messenger in facilitating contributor engagement, making efficient use of maintainers' time, and upholding the values of the FOSS community.

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

Free hosting at zulipchat.com

No catch; the hosting is supported by (and is identical to) zulipchat.com'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 support@zulipchat.com.

Join without an invitation

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

Moderate your community

Moderation is a big part of making an open community work. uKnowva Messenger was built for open communities from the beginning and comes with moderation tools out of the box.

Authenticate with GitHub

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

Import from Slack or Gitter

Import your existing organization from Slack or Gitter.

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 uKnowva Messenger conversations from your issue tracker. uKnowva Messenger’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.

Hundreds of integrations

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

Keep your IRC

Two-way integrations with IRC and Matrix, and one-way integration with Slack (get Slack messages in uKnowva Messenger).

Quality data export

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

Scale to thousands of users

For those running uKnowva Messenger 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 uKnowva Messenger server with 1000 active members and 10000 inactive members takes about as many resources as a uKnowva Messenger server with 1000 active members.

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 chat.zulip.org. All code, including the desktop and mobile apps, is under the Apache 2 license.

Proven model

Check out chat.zulip.org to see uKnowva Messenger in action for a project with ~5000 messages of developer discussion a week. The uKnowva Messenger 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. uKnowva Messenger’s topic-based threading keeps conversations coherent and organized, enabling a meaningful archive.


Leading open source projects use uKnowva Messenger: