Zulip for open source.

The Zulip core developers have decades of combined experience leading and growing open source communities. We use Zulip to 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, facilitating inclusion, and making efficient use of everyone’s time.

If you haven’t read why Zulip, read that first. The challenges with the Slack/Discord/IRC model discussed there are even more important for open source projects:

• Open source contributors are scattered all over the world and in every time zone. Traditional open source communication tools like email, forums, and issue trackers work well in this context, because you can communicate effectively asynchronously. A Slack community is a bad experience if you’re rarely online at the same time as most other members, and a result, Slack represents a huge regression in the global inclusivity of open source projects.
• Most contributors and potential contributors have other fulltime obligations and can only spend a few hours a week on an open source project. Because catching up on history in an active Slack organization is a huge waste of time, these part-time community members cannot efficiently use their time participating in an active Slack. So either they don’t participate in the Slack, or they do, and their other contributions to the project suffer.
• Maintainers are busy people and almost uniformly report that they wish they had more time to do focus work on their project. Because active participation in Slack fundamentally requires constant interruptions, maintainers end up making unpleasant choices between participating in the Slack community (limiting their ability to do focus work) or ignoring the Slack community (leaving it effectively without their input and potentially unmoderated).
• Writing to a busy Slack channel often means interrupting another existing conversation. This makes it harder for newer and shyer members to jump into the community. Often this disproportionately affects groups already underrepresented in open source communities.
• The lack of organization in Slack message history (and its 10K message history limit) mean that users asking for help cannot effectively do self-service support. This results in the community answering a lot of duplicate questions.

The overall effect is that Slack is a poor communication tool for projects that want to have an inclusive, global, open source community and effectively retain volunteer contributors.

Zulip’s topic-based threading model solves these problems:

• Contributors in any time zone can send messages and expect to get a reply and have an effective (potentially asynchronous) conversation with the rest of the community.
• Zulip’s topic-based theading helps include part-time contributors in two major ways. First, they can easily browse what conversations happened while they were away from the community, and prioritize which conversations to read now, skip, or read later (e.g. on the weekend). Second, Zulip makes it easy for them to have public conversations with participation from maintainers and other contributors (potentially split over hours, days, or weeks as needed), allowing them to fully participate in the work of the community.
• Maintainers can effectively participate in a Zulip community without being continuously online. Using Zulip’s keyboard shortcuts, it’s extremely efficient to inspect every potentially relevant thread and reply wherever one’s feedback is useful, and replying hours after a question was asked is still a good contributor experience. As a result, maintainers can do multi-hour sessions of focus work while still being available to their community.
• Every contributor has their own space to start a conversation (we recommend new contributors start a topic with their name as the topic). Asking a question never has to be an interruption of another conversation.

You can see this in action in our own chat.zulip.org community, which sends thousands of messages a week. We often get feedback from contributors around the world that they love how responsive Zulip’s project leaders are in public Zulip conversations. We are able to achieve this despite the project leaders collectively spending only a few hours a day managing the community and spending most of their time integrating improvements into Zulip.

Many communities that migrated from Slack, IRC, or Gitter to Zulip tell us that Zulip helped them manage and grow an inclusive, healthy open source community in a similar way. We hope Zulip can help your community succeed too!

Below, we’ve collected a list of Zulip features that are particularly useful to open source communities.

Free hosting at zulip.com.

The hosting is supported by (and is identical to) zulip.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@zulip.com.

Moderation suite.

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 out of the box.

Open invitations.

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

Authenticate with GitHub or GitLab.

Allow (or require) users to authenticate with their GitHub or GitLab account, instead of with a username and password.

Import from Slack, Mattermost, or Gitter.

Import your existing organization from Slack, Mattermost, 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.

If your community primarily uses a single programming language, consider setting a default language for syntax highlighting.

Permalink to conversations.

Zulip makes it easy to get a permanent link to a conversation, which you can use in your issue tracker, forum, or anywhere else. Zulip’s topic-based threading helps keep conversations coherent and organized so they are useful for posterity.

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 for your organization.

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.

Mirror IRC or Matrix.

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

Scales to 10,000s of members.

Zulip is designed to perform well in common use cases for open source projects, with features like soft deactivation to make message delivery efficient even when sending to a stream with 10,000s of inactive subscribers.

Full-text search of all public history.

Zulip’s full-text search supports searching the organization’s entire public history via the streams:public search operator, allowing Zulip to provide all the benefits of a searchable project forum.

Public archive.

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 indexed by search engines.

Currently implemented as an out-of-tree tool, though a native feature built into the Zulip server is coming soon.

Logged-out public access (coming soon).

Coming soon: Allow users to read and search public stream history in Zulip’s UI without first creating an account.

Quality data export.

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

Free and open source.

Unlike many modern "open source" applications that are actually Open Core, Zulip is 100% Free and Open Source software. All code, including for the server, desktop, mobile, and beta terminal apps is available under the Apache 2 license.

We love helping other open source communities and prioritize feature requests from open source communities the same way we prioritize feature requests from paying customers.

So if there’s something we could improve to make Zulip the obvious choice either for you or your community, contact us and we'll do what we can to help!