In the ninth year in a row, ZuriHac 2025 took place as a physical event from Saturday, June 7 to Monday, June 9, 2025 at the Rapperswil-Jona campus of the Eastern Switzerland University of Applied Sciences (OST).
ZuriHac is the world's largest practitioner's conference on principled programming centred around the functional programming language Haskell. It has acquired somewhat of a cult status within the programming languages community, and features invited talks from leading experts from industry and academia, as well as hands-on beginners and advanced tracks.
Haskell and Its Role in Programming Language Research
Haskell is a general-purpose, statically-typed, pure functional programming language with type inference and lazy evaluation. Designed for teaching, research, and industrial applications, Haskell has pioneered a number of programming language features such as type classes and monadic input/output and has influenced many other programming languages. It is seen by many as one of the main vehicles for programming language research.
This year's invited talks focused on some of community-related and technical areas of functional programming and Haskell. Here are a few highlights:
Lennart Augustsson, programming language pioneer and currently working at Epic Games, talked about MicroHs, compiler simplicity, the history of Haskell and functional programming, dependent types, and writing trustworthy code; Tom Ellis, a software engineer at Groq talked about the history of effect systems; Zoë Kooyman, executive director of the Free Software Foundation, talked about freedom-preserving software, ethics, and empowering developers through appropriate software licensing.
Tracks, Talks, and New Formats
Additionally, there were a number of tracks, ranging from the Web Assembly and Nix tracks by Cheng Shao and Malte Ott respectively, and a beginners’ track by Andres Löh of Well-Typed. There was also a Track on Category Theory hosted by Dr. Richard Southwell from Planted Space, who is also famous from his YouTube channel on fundamental mathematical concepts. Category theory is a general theory of mathematical structures and their relations whose concepts such as Functors and Monads have been used in Haskell and increasingly in other programming languages.
We also took the opportunity this year to try out some new formats for talks and discussions: Pedro Abreu (host of the Type Theory for All podcast) and Farhad Mehta (OST Professor, as co-host of the Haskell Interlude podcast) co-hosted a live podcast interview with Lennart Augustsson on evolution of programming and Haskell as well an expert panel on tooling, teaching & real-world use of Haskell. Brent Yorgey, assistant professor at Hendrix College and co-author of the famous Diagrams package and Swarm 2D programming game, hosted a competitive programming session using Haskell.
Community Projects and Looking Ahead to ZuriHac 2026
As always, there was also a lot of work done on community and personal project. There were about 30 projects registered in areas as diverse as compilers, education, IDE support, crypto currencies, typesetting, game development, hardware design, effect systems implementation, build automation, image processing and security.
A recording of all invited and advanced tracks is freely available online. Details of all invited talks and tracks can be found on the ZuriHac 2025 web page. All in-person ZuriHacs since 2017 have taken place at the OST campus in Rapperswil. ZuriHac 2026 is planned to take place at the OST from 06 June to 08 June 2026. Stay tuned to the following URL for more updates.