Haskell Foundation August 2023 Update

Seeking an Executive Director

This is my second-last monthly update. Last week, I announced that I’ll be leaving my role as Executive Director of the Haskell Foundation at the end of September, returning to a full-time software development job. An rare offer came by to work on essentially all of my main technical interests at once, with great colleagues, and I decided (after much soul-searching) to take it. More information is available on my announcement post.

As a consequence, the HF is seeking a new ED. If you think that you might be interested, but are unsure, or if you’d just like to hear more, then I’d be happy to spend some time with you and answer your questions. Email me, and we can make an appointment. The Chair of the Board Richard Eisenberg is also available to answer questions. There are lots of ways to do this job well, and just as I’m not a clone of Andrew, you don’t have to be just like me to succeed. All applications received by 2023-09-29 will receive full consideration, but applications will be accepted until the position is filled.

I’ll be spending my remaining time preparing the organization for the transition and doing my best to set up my successor for success. Thank you all for the opportunity to work with you through the HF.

Technical Agenda


Bryan continues to work to make GHC’s CI better for everyone. On top of that, he founded a Haskell CI group in which practitioners of CI for Haskell can share experiences and information. Here are his weekly logs:

Error Message Documentation

The Haskell Error Index celebrated its 100th documented error in August! Since then, even more errors have been documented.

David Binder, who has volunteered on the project for more than a year, has become the primary maintainer of the project. Thank you, David!

Technical Working Group

Meeting notes:

Stability Working Group

In addition to the usual topics of discussion, the Stability Working Group has been looking into finding better ways to clarify and communicate expectations surrounding the stability or experimental status of various language and implementation features. We submitted a proposal that GHC more precisely define the lifecycle of language extensions and include configurable warnings about the stability policies of said extensions to the GHC Steering Committee, which is currently being discussed.

Meeting notes:


GHC Contributors’ Workshop

Ever since the end of the 2023 GHC Contributor’s Workshop, we’ve been working to bring as much additional value as possible to the Haskell community. The videos were edited and uploaded in July, and during July and August, we had them transcribed. All videos now include subtitles, making them more useful for everyone.

This was the last remaining thing to be done after the workshop. Thank you again to everyone who attended, our presenters, our volunteers, and to my co-organizer Farhad Mehta of OST Eastern Switzerland University of Applied Sciences.


The Haskell Interlude Podcast released interviews with Ranjit Jhala.


We are very happy to announce that Mercury has renewed their support at the Applicative level! Mercury delivers banking and credit card services to more than 100,000 startups (though it’s important to them that I point out that they’re a financial technology company, not a bank, and that banking services are provided by Choice Financial Group and Evolve Bank & Trust, both members of FDIC). Haskell is a core part of Mercury’s tech stack, and they employ around 150 full-time software engineers, around 2/3 of whom are writing Haskell code. Their company culture prioritizes training good developers in Haskell over finding outside Haskell expertise, and their formidable in-house training program has brought many people to Haskell. As part of their commitment to bringing Haskell to more people, two of their engineers have written books to help people who want to write in Haskell understand how to apply it to the real world, including Effective Haskell by Rebecca Skinner and Production Haskell by Matt Parsons. In addition to their generous sponsorship of the Haskell Foundation, Mercury has funded specific improvements to GHC and HLS that make interactive tooling work better on large codebases.

We’d also like to thank TripShot for renewing their sponsorship at the Functor level! TripShot provides an integrated platform for managing transportation systems, from bus networks to on-demand shuttles to parking, that supports both real-time operations and long-term planning and forecasts. In addition, TripShot’s mobile apps allow passengers to plan their trips, pay for rides, and find out exactly where vehicles are. TripShot’s backend is written in Haskell, developed and maintained by a fully-remote team of 14 developers, of which the majority work primarily in Haskell. Using Haskell allows TripShot to quickly iterate on their codebase as new requirements arise while still maintaining a high degree of confidence in its correctness, and they’ve documented many of their valuable techniques in their engineering blog. TripShot’s ongoing sponsorship makes it possible for the Haskell Foundation to continue our work.

All of our work is made possible by our individual contributors and our sponsors. Thank you so much for your support.