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](/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 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](/help/manage-who-can-join-and-invite).
You can also link to your Zulip with a [badge](/help/join-zulip-chat-badge)
in your readme document.

### Moderate your community

Moderation is a big part of making an open community work. Zulip was built
for open communities from the beginning and comes with
[moderation tools](/help/moderating-open-organizations) out of the box.

### Authenticate with GitHub

Allow (or require) users to
[authenticate with their GitHub account][github-auth], instead of with their
email address.
[github-auth]: https://github.com/zulip/zulip/blob/7e9926233/zproject/prod_settings_template.py#L112

### Import from Slack or Gitter

Import your existing organization from [Slack](/help/import-from-slack) or
[Gitter](/help/import-from-gitter).

### Syntax highlighting

[Full Markdown support](/help/format-your-message-using-markdown), including
syntax highlighting, makes it easy to discuss code, paste an error message,
or explain a complicated point. Full LaTeX support as well.

### Permalink from issues to chat

[Permalink to Zulip conversations](/help/link-to-a-message-or-conversation)
from your issue tracker. Zulip’s topic-based threading keeps conversations
coherent and organized.

### Link from chat to issues

Efficiently refer to issues or code reviews with notation like `#1234` or
`T1234`. You can set up any regex as a
[custom linkification filter](/help/add-a-custom-linkification-filter) for
your organization.

### Hundreds of integrations

Get events from GitHub, Travis CI, JIRA, and
[hundreds of other tools](/integrations) right in Zulip. 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 Zulip).

### Quality data export

Our high quality [export](/help/export-your-organization) and
[import](https://zulip.readthedocs.io/en/latest/production/export-and-import.html)
tools ensure you can always move from
[zulipchat.com](https://zulipchat.com) hosting to your own servers.

### 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.

### Free and open source

Don’t like something? You can
[open an issue](https://github.com/zulip/zulip/issues),
[submit a patch](https://zulip.readthedocs.io/en/latest/development/overview.html),
[fork the project](https://github.com/zulip/zulip), or chat with us directly
at [chat.zulip.org](https://chat.zulip.org). All code, including the
[desktop](https://github.com/zulip/zulip-electron) and
[mobile](https://github.com/zulip/zulip-mobile) apps, is under the Apache 2
license.

### Proven model

Check out [chat.zulip.org](https://chat.zulip.org) 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.