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ZuriHac 2021 is over: go here for ZuriHac 2022!


ZuriHac is the biggest Haskell Hackathon in the world: a completely free, three-day grassroots coding festival organized by Zürich Friends of Haskell. It features fantastic keynotes, hands-on tracks, and of course lots of hacking and socializing!

ZuriHac takes place Friday 18 June — Sunday 20 June 2021.


Due to the still ongoing pandemic, ZuriHac 2021 will be a virtual event. We hope to return as a real-life event in 2022.



ZuriHac 2021 is an online event, but we still require registration. After registering, you will receive an invite to our Discord server, where we will host the Hackathon.

Registration for ZuriHac 2021 is closed.

Go here for ZuriHac 2022!


It is also available as a Public Google Calendar, that you can e.g. add to your smartphone or personal calendar.

Start End Kind Link Title
2021-06-18T18:00:00+02:002021-06-18T19:30:00+02:00talk #speaker-john-hughes Opening & Talk by John Hughes: Testing smart contracts with QuickCheck
2021-06-18T19:45:00+02:002021-06-18T20:45:00+02:00partner Digital Asset: Haskell in the industry, DAML, Q&A
2021-06-19T10:00:00+02:002021-06-19T11:15:00+02:00talk #speaker-ollie-charles Talk by Ollie Charles: Rel8: A new database access library for Haskell
2021-06-19T11:30:00+02:002021-06-19T12:30:00+02:00partner Fretlink: Fun haskell for regular stuff, Q&A
2021-06-19T12:30:00+02:002021-06-19T13:30:00+02:00partner Tweag: building Haskell with Bazel
2021-06-19T14:00:00+02:002021-06-19T15:00:00+02:00beginner Haskell install party
2021-06-19T16:00:00+02:002021-06-19T17:30:00+02:00beginner#beginner-track Beginner Track
2021-06-19T14:00:00+02:002021-06-19T17:00:00+02:00advanced#advanced-track Advanced Track: Optics in the abstract
2021-06-19T17:00:00+02:002021-06-19T18:00:00+02:00talk GHC Panel Discussion with Simon Peyton Jones
2021-06-19T18:00:00+02:002021-06-19T19:15:00+02:00talk #speaker-emily-pillmore Talk by Emily Pillmore: Haskell Foundation Progress Update
2021-06-19T19:30:00+02:002021-06-19T21:00:00+02:00beginner#ihp-workshop IHP Track
2021-06-19T19:30:00+02:002021-06-19T21:00:00+02:00advanced#unison-workshop Unison Track
2021-06-20T10:00:00+02:002021-06-20T11:15:00+02:00talk #speaker-veronika-romashkinaTalk by Veronika Romashkina: Lift Unliftable (and unlift liftable)
2021-06-20T11:15:00+02:002021-06-20T12:00:00+02:00advanced #serokell-track GHC: Dependency Analysis of Haskell Declarations
2021-06-20T12:00:00+02:002021-06-20T13:00:00+02:00advanced #serokell-track How to make the most out of servant
2021-06-20T13:00:00+02:002021-06-20T15:00:00+02:00beginner#mob-programming Mob Programming
2021-06-20T16:00:00+02:002021-06-20T17:30:00+02:00beginner#beginner-track Beginner Track
2021-06-20T14:00:00+02:002021-06-20T17:00:00+02:00advanced#advanced-track Advanced Track: Understanding memory usage with eventlog2html and ghc-debug
2021-06-20T18:00:00+02:002021-06-20T19:15:00+02:00talk #speaker-sandy-maguire Talk by Sandy Maguire: A New Kind of Programming: Tactic Metaprogramming in Haskell
2021-06-20T19:30:00+02:002021-06-20T21:00:00+02:00beginner#ihp-workshop IHP Track


Emily Pillmore

Emily is a long-time functional programmer, Haskell developer and CTO of the Haskell Foundation. Her research interests include Homotopy Theory, Category Theory and Topology, and she recently co-authored a paper about Profunctor optics.

John Hughes

John Hughes holds a professor position at the Chalmers University of Technology. In the Haskell community, he is mostly known for his work around QuickCheck, that changed the way how functional programmers test programs. He also leads QuviQ, a software testing consultancy.

Veronika Romashkina

Veronika is an enthusiastic functional programmer and uses Haskell for open source work as well as in production. She co-founded Kowainik, who've provided us host of a useful tools and tutorials. On top of that, she is also one of the authors of the wonderful Bind the Gap magazine.

Sandy Maguire

Sandy is best described somewhere between independent researcher and voluntarily-unemployed bum. He wrote two books about Haskell, Thinking with Types and Algebra-Driven Design, as well as the library polysemy.

Ollie Charles

Ollie is a Haskell Developer well known for his 24 Days of Hackage and 24 Days of GHC Extensions series. He also maintains a number of Haskell projects, including a really cool implementation of Quake 3 in Haskell & Vulkan.


We have a number of tracks for all you knowledge-hungry people.

These cover any level between beginner and expert, and we've taken special care to have content for intermediate Haskell programmers. There has never been a better time to learn and apply some real-world Haskell skills!

Beginner Track

Julie Moronuki and Chris Martin of Typeclasses will teach a class for beginner Haskell programmers.

No prior Haskell experience is necessary, and you will learn fundamentals as well as some applied skills over the course of the two sessions.

For this track, you have to have a working Haskell installation. We'll hold an install party before the beginner track to help you with that. We recommend ghcup to install the compiler and cabal, together with VSCode and the Language Server extension. Installing Haskell in 2021 is super easy!

IHP workshop

The IHP web framework is a really cool Haskell web framework combines the productivity of Ruby-on-Rails with the performance and robustness of Haskell. The community around it is growing really fast, in part because it comes with highly polished tools and doesn't need deep technical knowledge to build useful websites very quickly.

The creators of IHP, digitally induced, will hold tutorials that teach you how to get productive with the framework. We recommend that even total beginners check it out, as some people have learned Haskell simply through using IHP for a practical application.

Advanced Track

Similar to last year, we have the privilege to get advanced Haskell training from our friends at Well-Typed. This will take the form of two independent sessions, distributed over the course of two days.

Unison workshop

Unison is an exciting new programming language that shares Haskell's syntax (in addition to being implemented in it). The big ideas in Unison are content-addressable code and a focus on creating a language in which it is natural to express distributed systems.

Rúnar Bjarnason of Unison Computing will give you an intro to the language, and hold a hands-on tutorial.

If you can't wait, check out the 2019 Strangeloop introduction to the language.

Serokell Track

This year year we're delighted to have Serokell present two topics:

  • Dependency Analysis of Haskell Declarations in GHC.
  • How to make the most out of servant.

The servant talk is geared towards industrial practicioners, so please don't hesitate to join if you're excited about practical applications but don't consider yourself an expert.

Mob Programming : Angry Lambdas

By Caroline Gaudreau of Fretlink
and Gaël Deest of Tweag

Collectively implement a small Angry Birds clone in Haskell using the Gloss library for graphics and user interaction, and the Chiphunk library for physics simulation!

This workshop is targeted at beginners with a basic understanding of Haskell. You only need to know algebraic datatypes, pattern-matching, and a bit of IO.

Note: This is a mob programming event: participants will take turn at the (virtual) keyboard, while listening to suggestions and comments from the rest of the crowd.

To participate, you will need VSCode with the LiveShare extension, install these before joining the session.


Of course, it wouldn't be a Hackathon without projects to hack on! You can find the list of projects here and even add your own!


Digital Asset Digitally Induced Fretlink Hackworth OST Serokell Tweag I/O Type Classes Unison Well-Typed



If you have any questions before the event, please reach out to Jasper Van der Jeugt, Juri Chomé or Farhad Mehta. We also monitor our official Twitter account.

The primary medium to communicate with other participants is our Discord server. You will receive an invite to that after you register. We use the hashtag #zurihac on Twitter.


The main organizers for ZuriHac 2021 are Jasper Van der Jeugt, Juri Chomé, Farhad Mehta and Bieke Hoefkens.

Additional volunteers include Andreas Herrmann, Artem Chirkin, Arvin Moezzi, Charles Till, Gleb Peregud, Ingrid Vettiger, Ivan Kristo, Mathias Koerner, Niklas Hambüchen, Silvio Böhler, Simon Meier and Tomas Carnecky.


Each participant will retain ownership of any and all intellectual and industrial property rights to his or her work created or used during the Hackathon.

ZuriHac uses the Berlin Code of Conduct.