The R Project now has a Zulip instance for informal chat about developing, maintaining and supporting R. The Zulip (pronounced “zoo-lip”) will replace the R Contributors Slack group, with a slightly broader scope, also covering wider R Foundation activities.
The R-devel mailing list remains the official channel for technical discussions about R’s development and R’s Bugzilla remains the official place to report bugs and open feature requests. However, the Zulip provides a supportive space to get initial feedback on ideas and work in progress, especially for novice contributors. It also provides a useful communication channel for working groups and collaborative events such as R Dev Days.
Motivation
When the R Contribution Working Group set up the R Contributors Slack in November 2020, the free tier gave access to the most recent 10,000 messages, which would have covered several years of messages. Since September 2020, posts older than 90 days are no longer visible, making it difficult to collaborate on tasks that span several months, which is particularly common when people are contributing in their spare time. Although we have been making manual exports of our Slack data and sharing them as JSON files on GitHub, this is clearly far from optimal.
There are other limitations of Slack that have affected collaboration and communication. The free tier does not support email addresses for channels, so the #bugzilla-inbox channel that relayed new comments on bugs.r-project.org relied on a third-party automation with a limit of 100 messages per month - a ceiling we regularly hit during busy periods, such as a month with one or more R Dev Days. Some users found the email notifications unreliable, so would miss when people were trying to contact them. Moreover, as a proprietary platform, Slack was never popular among the R Core Team, so it provided little opportunity for interaction with core developers.
Why Zulip
Zulip is a better fit for the R Project: not only is it open source, but as a company, Zulip supports open source. They are sponsoring the R Project by providing a free standard cloud plan, enabling us to keep our full chat history.
A number of other open source projects are using Zulip, including Python, Julia and Rust. Bioconductor and NumFOCUS moved from Slack to Zulip last year. Given that members of the R community are often involved in other open source communities, we know there will be some experience with Zulip, and we can hopefully minimise the number of platforms our community needs to use.
Zulip also has some attractive features that Slack does not, including:
Topics, that make it easier to hold both sychronous and asynchonous conversations.
The ability to move messages to keep related chat together.
Markdown and KaTeX rendering.
An in-built feature to run polls.
See the full documentation for more.
Timeline
We are launching the Zulip according to the following timeline:
August 19th - September 22nd: members invited from the R Foundation, R Contribution Working Group, RSMF project, and R Project Sprint 2026 participants, to test the set-up and give feedback.
September 22nd: sign-up page opened to all contributors and supporters of R. From this date the R Contributors Slack will no longer be open to new sign-ups. Existing members will be encouraged to sign up to the new Zulip.
October 27th: planned date for archiving all R Contributor Slack channels.
Joining the R Project Zulip
You can join the Zulip as follows:
Sign-up at https://r-project.zulipchat.com. Note that we will not be migrating members from Slack to Zulip automatically.
Read our Zulip guide for R Contributors.
A welcome bot will greet you when you first join with further pointers on effective participation.
We encourage you to read Zulip’s getting started guide to learn more.
Acknowledgements
This work was supported by the Research Software Maintenance Fund, managed by the Software Sustainability Institute and funded by UKRI grant reference AH/Z000114/1.
We’re grateful to Josh Triplett from the Rust Community and Maria Doyle from Bioconductor, for their advice on Zulip and conversations about the transition process.