Zürich Friends of Haskell

The Zürich Friends of Haskell is a club founded to foster the worldwide knowledge of functional programming, and Haskell in particular. We organise meetups and events in the Zürich area.

About us

The HaskellerZ meetup group has been around since 2011. After organising many meetups and events, in particular ZuriHac, which attracts people from all over the world, there was a need to formalise our group a bit more.

In the short term, this allows us to work together better with sponsors for ZuriHac. In the long term, however, we would like to guarantee the long-time success of a Zurich-based Haskell interest group, not dependent on one or two key volunteers.

The rules are set up so that we encourage non-monetary contributions (e.g. giving a talk). Of course, membership is optional and not required to attend any of our events.

Become a member!

For members, we ask a yearly contribution of either:

  1. giving at least one talk at the Zurich HaskellerZ meetup,
  2. helping organize ZuriHac in an official role,
  3. serving on the board of directors for the Zurich Friends of Haskell, or
  4. providing other voluntary work asked for by the board of directors.

Sign up for Membership

Occasionally, we reach out to our members with volunteering opportunities. Also, once a year we would send you an email to confirm and update the membership.

Next meetup

(External) D. Christiansen: Programming and Proving with Dependent Types & Lean

Tuesday 6 June, 10:00

This event will be a guest lecture given by David Thrane Christiansen for the Computer Science department at OST Rapperswil, which we are happy to announce has been opened to interested members of HaskellerZ.

While most programming languages allow types to take other types as arguments, as in List Int and List String, dependent types allow any program to appear in types. The type of lists can describe not only what type each entry in the list has, but also how many there are, and the type of the append function can state that the length of the resulting list is the sum of the lengths of the input lists. Dependent types are powerful enough that they can be used as logic in which to prove arbitrary mathematical theorems. This lecture will provide a hands-on demonstration of programming and proving with dependent types in Lean, an interactive theorem prover developed at Microsoft Research.

David has been doing functional programming for twenty years, and he's been working with dependent types for a decade. Together with Daniel P. Friedman, he wrote _The Little Typer_, a dialog-form introduction to the key ideas of dependent types. He is also the author of Functional Programming in Lean, a free online book about using the Lean theorem prover as a programming language. He has contributed to the dependently typed language Idris and worked in industry on program analysis tools, election security, secure parsing of binary formats, and domain-specific languages for the financial sector. Since May 2022, he is the Executive Director of the Haskell Foundation.

Past meetups


Our main yearly event is the organisation of ZuriHac, a yearly Haskell Hackathon that attracts over 300 attendees. It is probably one of the oldest and definitely the largest Haskell Hackathon currently in existence.

The first ZuriHac was organised in 2010 at the Zürich Google office by Johan Tibell and Christophe Poucet. Currently, we are organising it at the Hochschule für Technik Rapperswil with the help of many Zürich Friends of Haskell members and volunteers.


We try to record all of our meetups and keynotes so Friends of Haskell who are not in the Zürich area can enjoy the content as well.

This playlist contains all our Haskell-related videos.

We have also collected the slides of the presentations in this repository. Unfortunately, the collection is currently incomplete.


Current board members of the Zürich Friends of Haskell association:

Past members: