2024 Haskell Ecosystem Workshop

Building on-ramps for the Haskell Ecosystem and its Tools

Location: Rapperswil, Switzerland
Dates: June 6-7, 2024

We are excited to announce the 2024 Haskell Ecosystem Workshop, June 6-7 2024, organized by the Haskell Foundation and the OST Eastern Switzerland University of Applied Sciences! This is a workshop for those who want to gain a deeper understanding of the Haskell tooling ecosystem, whether to better leverage those tools or to become contributors.

In this two-day event, held on the lakeside campus of OST in lovely Rapperswil, Switzerland, you can learn what you need to know in order to get started working on these tools. We’ve asked the presenters to identify ‘good first issues’ for those wanting to get their feet wet on contributing. Because the workshop is immediately prior to Zurihac 2024, you will have the opportunity to tackles one of these issues while the core developers are easily available!

The following speakers have been confirmed, with more to follow:

  • Michael Peyton Jones: Haskell Language Server
  • Julian Ospald: GHCUp
  • Richard Eisenberg: GHC
  • Alan Zimmerman: ghc-exactprint
  • Hécate Choutri: Haddock and Documentation
  • Fraser Tweedale: Security Response Team
  • Mike Pilgrim: Stack and Stackage
  • Same Derbyshire: Cabal

There will also be experts on ecosystem-wide issues (e.g. Security), in order to facilitate conversations about how to address cross-cutting issues in our tooling ecosystem.

We will update the list of confirmed speakers as we receive confirmation.

In-Person Attendance

Registration for in-person attendance will be managed via Eventbrite. Because of the space available registration will be limited to the first 70 participants. Monad and Applicative level sponsors to the Haskell Foundation have a set of reserved seats. These reserved seats will be released to the general pool if they go unused by the sponsors.

The registration link is available on Eventbrite

Video Recordings and Live Streaming

We will record all presentations and make them available online. We also plan to stream the talks live. More details on the streaming will come as it becomes available.

The Workshop

At this workshop, you can learn the design and architecture for common tools in the Haskell Ecosystem. GHC, Cabal, HLS, GHCUp, Stackage, etc. all have teams working on maintaining and improving Haskell environment for Haskell programmers.

This is a practical workshop: any theory presented will be in service of building things! We want attendees to feel empower to contribute to these tools and walk away with a better understanding of how they might do so.

Additionally, the speakers will be available to answer questions and to provide mentorship during Zurihac itself, so this is a great opportunity to finish your first MR.

We expect that participants already know Haskell and have worked on some form of programming language implementation in the past, whether as students, at work, or just for fun. Concepts such as parsing, type checking, unification, and code generation should be familiar, but we don’t expect participants to already be experts.

Practical Information and Schedule

The workshop will be held at the Rapperswil-Jona campus of OST. It is right next to the Rapperswil train station, at Oberseestrasse 10. The Zurihac 2024 site has instructions for transportation between Rapperswil and Zürich.

All talks and presentations will be held in an air-conditioned classroom that will be configured conference-style, which means that most seats won’t have a table or desk attached. During the event, we’ll let you know which additional spaces are good for compiler hacking. We will post the exact room number when that becomes available.


This is a hands-on workshop, so please bring the equipment that you need to work on GHC (laptop, power adapter, etc). Swiss electricity is 220 volts, 50 Hz AC. Swiss power outlets are different than in many European countries, so please bring an appropriate adapter if necessary. Drinking fountains are not common in Europe, so please bring a refillable water bottle.


  • Swiss power adapter(s), if necessary
  • Refillable water bottle
  • Working account on gitlab.haskell.org
  • Checked out and built a recent GHC from source
  • Checked out and built the JavaScript backend from source


The full schedule of the program is still being drafted.

8:00-9:00 Registration
9:00-9:20 Welcome and Intro Farhad Mehta and Jose Calderon
9:30-10:30 A vision for Haskell Documentation Hécate
10:45-11:45 Talk
12:30-13:30 Lunch at Mensa (Note: food is served only until 13:15)
13:30 - 14:30 Haskell Language Server Michael Peyton Jones
14:45 - 15:45 Haskell Security Response Team Fraser Tweedale
16:00 - 17:00 Haskell Error Index: Interactive Session David Binder
17:00 - 17:50 Discussion Topic: Haskell Stability
17:50 - 18:00 Closing Remarks Farhad Mehta and Jose Calderon
8:00-9:00 Unstructured time
9:00-9:20 Welcome and Practical Information Farhad Mehta and Jose Calderon
9:30-10:30 GHC Richard Eisenberg
10:45-11:45 GHCUp Julian Ospald
12:30-13:30 Lunch at Mensa (Note: food is served only until 13:15)
13:30 - 14:30 ghc-exactprint Alan Zimmerman
14:45 - 15:45 Thoughts on Cabal Sam Derbyshire
16:00 - 17:00 HLS Issues Zubin Duggal
17:00 - 17:50 Stack and Stackage Mike Pilgrim
17:50 - 18:00 Closing Remarks Farhad Mehta and Jose Calderon

All times are in CEST using a 24-hour clock. Speakers have been asked to plan appropriate breaks during their timeslots.

We don’t expect every participant to attend every presentation. It’s perfectly acceptable to skip a topic that you’re less interested in so you can hack on a topic that you are interested in, taking advantage of ready access to the experts for hands-on assistance.

Lunch and Refreshments

We will eat lunch in the OST canteen, called Mensa. While Mensa is open from 11:00-13:15, it is very busy from 11:45-12:30 because classes are in session, and they’ve asked that we go before or after. Talks have been scheduled to account for this.

Coffee, tea, and fruit will be provided. There is also easy access to a tap for water. Dinner is on your own. There is a grocery store very near the campus where other products can be purchased as well.


Due to space constraints and to enable scholarships for student participants, there will be a fee for full on-site participation. Fees will be used to cover travel costs for presenters, other direct costs of running the event, and students who don’t have other funding to attend. The fee depends on participant category:

  • Enrolled students ($40) are participants who are enrolled full-time at an educational institution.

  • Individual professionals ($400) are no longer students and are interested in working on GHC for their own purposes.

  • Corporate participants ($1200) are being paid by their employer to attend so that they can use the knowledge that they gain on the job. Corporate participants will have their company name on their name tag and their company will be listed on the event web page as a supporter of the event.

All fees are in US dollars. We want the event to be as accessible as possible, given our limitations, so if the fee is a barrier to attending, please contact Jose Calderon at jmct@haskell.foundation to discuss a reduced or waived fee—this goes for all three categories of participant.

A certificate of completion will be available on advance request to students who attend the entire event.

Remote participation will make use of the Zurihac infrastructure. We will do our best to stream presentations and to post recordings as quickly as possible, and we will also have a chat system for remote participants.

If you or your company would like to sponsor the event, enabling more students to have financial support to attend, please contact Jose Calderon at jmct@haskell.foundation.

Individual Sponsors
GitHub IOHK Juspay Meta
CarbonCloud Digital Asset ExFreight Mercury Obsidian Systems Platonic Systems Tweag Well-Typed
Artificial Channable FlipStone Freckle Google HERP MLabs TripShot
To learn more about the Haskell Foundation
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