📢 Yann Hamdaoui just published the second part of his #Topiary tutorial, teaching you how to build a language formatter from scratch. Dive right in and learn how to handle and customize single-line and multi-line layouts. www.tweag.io/blog/2025-10...

Thanks to everyone for stopping by our booth at PyData Paris! We enjoyed connecting with so many people passionate about data science, machine learning, and open source innovation. We hope to see you again soon! #PyDataParis

We're back! Mark your calendars: BOBkonf returns on 13 March 2026 … … and our Call for Contributions is up, with a submission deadline of 17 Nov 2025. Find out more here: bobkonf.de/2026/cfc.html

ICFP and SPLASH are around the corner, starting on the 12th October in Singapore. This year we're coming with two presentations.

A bit of casual, yet pleasant news. As of a week ago or so, #Nickel files are now syntax highlighted on Github. Many thanks to contributor extraordinaire Mikhail Katychev, who made the PR to Github's Linguist github.com/github-lingu...

There was a performance bug in recent Ormolu. The fix is terrifying github.com/tweag/ormolu...

PyData Paris 2025 is only one week away! Join us for a live talk on October 1 to hear about how the CodeCommons collaboration makes training AI models on code more transparent, sustainable, and fair. 💡 Get your tickets today: pydata.org/paris2025/ti... #PyDataParis

Alexey Tereshenkov wrote a second blog post on dependency graphs. In this one, he breaks down the issues that you might need to deal with when managing the dependencies of a project at scale. Read to understand the sort of problems build systems engineers face. www.tweag.io/blog/2025-09...

The stabilisation of `cargo publish --workspace` is front page news today. Rustaceans, we hope it serves you well.

We sat down with Phil Wadler, one of the most influential folks in the Haskell community, functional programming, and programming languages, responsible for type classes, monads, and much more! haskell.foundation/podcast/70/

The Software Heritage #OpenScience Strategic Blueprint is now available. This roadmap lays out a comprehensive plan to make software a first-class output of research. https://www.softwareheritage.org/2025/09/12/open-science-software-blueprint/ #reproducibility

#AmeriHac – The hackathon by the #Haskell Foundation in New York City has been announced for the 7th and 8th of February 2026! discourse.haskell.org/t/the-inaugu...

Great talk! (I saw it live at #MuniHac a few hours ago.) If you care about programming-in-the-large, definitely watch it!

Google Summer of Code #gsoc blog post! Read Xavier Góngora's tour of his project to bring #LiquidHaskell a step closer to large code bases www.tweag.io/blog/2025-09...

On my way to #MuniHac #haskell

Couldn't make it to #NixCon this year? You can still enjoy all of our talks with our live streams! 2025.nixcon.org/live

Check out Alexey Tereshenkov's new blog post for a practical look at dependency graphs – what they are, why they matter, and how understanding them lets you optimize builds, and keep your codebase healthy. Perfect for engineers looking to level up on build systems! www.tweag.io/blog/2025-09...

See you all next week at #MuniHac 2025, hosted by @tngtech.com! bsky.app/profile/tngt... #Haskell

Final call, programmers: A UNESCO exhibit needs your code. Show how your work shapes our world. Submission deadline Sept. 8 https://www.softwareheritage.org/2025/07/07/code-exhibit-unesco-cfp/

Come to @aborgna.bsky.social's talk (and panel discussion) on @quantinuum.bsky.social's Guppy programming language this afternoon if you are at #IEEEQuantumWeek. We got some cool T-shirts!

FUNARCH 2025 call for lightning talks is up! Come give a 5-10 minute presentation about your hexagonal architecture, or the system that you've architected in a functional language, or your experience using FP in the large! conf.researchr.org/home/icfp-sp...

My second blog post about CodeQL has been published 🎉 www.tweag.io/blog/2025-08... CodeQL is a static security analyzer from GitHub. Curious about the experience you would have with CodeQL queries in production? That's the post to learn about it 👀

I've put preprints of our FUNARCH papers on my home page (“Six Years of FUNAR - Functional Training for Software Architects”, “Evolution of Functional UI Paradigms”). www.deinprogramm.de/sperber/pape...

Another NixCon 2025 talk to highlight from our team! Join Silvan Mosberger on Sept 5th as he shares the journey of establishing the official Nix formatter. We're a Silver Sponsor of NixCon and look forward to connecting with everyone in Switzerland!🇨🇭 Get your tickets: 2025.nixcon.org #NixCon2025

The Call for the 2026 International Symposium on Functional and Logic Programming (FLOPS) is open - the symposium will be May 26-28 in Akita, Japan. Deadline for the CfP is Dec 8 (abstracts) / Dec 16 (submissions). Send us your best on the best of both worlds! functional-logic.org/events/flops...

#Nickel release v1.13! New feature contributed by new contributor bthmc: nickel format --check e.g. for CI. Thank you very much bthmc! And thank you to all the other contributors! Other than this, mostly bug and documentation fixes, see the full notes github.com/tweag/nickel...

#OCaml #OCamlPlanet

If you always wanted to know how Bluesky and the AT protocol work under the hood, what the moving parts are, and how they connect, I highly recommend this blog post!

#CodeQL is GitHub's static analysis tool, a powerful full-program analyser that can detect smells and track tainted data, but it can be difficult to get started. Check out this new(ish) blog post, by @smelc.bsky.social, to get over this hump and write your first query! www.tweag.io/blog/2025-08...

The videos for the Haskell Implementors Workshop www.youtube.com/playlist?lis... (chaired by our own @andrherr.bsky.social ) and Haskell Ecosystem Workshop www.youtube.com/playlist?lis... have been released! A few highlights from us below. Tell us *your* favourite talks!

📣 Exciting news 📣 We're a Silver Sponsor of NixCon 2025! Will you be there? We have several talks planned that you won't want to miss. Learn more about the event and get your tickets today: 2025.nixcon.org #NixCon2025

Sweet!

Blog post from a couple weeks' ago by Claudio Bley on integrating Nix with Buck2, featuring our newly open-sourced ruleset, buck2.nix! Check it out and enhance your build experience! www.tweag.io/blog/2025-07... #Nix #Buck2 #OpenSource #DevTools

New blog post by Mesut Güneş on performance testing. In this first of a series, Mesut proposes a typology of performance tests and how they fit in your continuous testing process. #performance-testing #software-testing #software-quality #automation www.tweag.io/blog/2025-08...

We recognise this name 🤔

As part of my job at @tweag.io and I gave an introduction to the Bazel build system at @lu.voxxeddays.com that is now online: www.youtube.com/watch?v=fUhu... Watch to see how Bazel will help you build your gigantic codebase at scale, cache build and test results, and attain fame and glory (yes!).

As part of my job at @tweag.io, I wrote an introduction to @github.com's CodeQL static analyzer: www.tweag.io/blog/2025-08... CodeQL performs whole program analysis, using a flexible query language. But the ecosystem still has rough edges, hence my introductory post! Enjoy 👑

In our latest blog post, Robinson Marquez introduces the new LaunchDarkly Svelte SDK that he contributed. Letting you toggle features in real-time and run A/B tests in Svelte applications. Complete with a tutorial www.tweag.io/blog/2025-07... #Svelte #FeatureFlags #LaunchDarkly #WebDevelopment

Our Scalable Build Group has just published issue 30 of their build //newsletter. Subscribe for updates on the latest developments in the build system space: www.build.news #opensource #engineering

Yet another small OCaml/OxCaml diff has been squished! Polymorphic parameters has just gotten merged upstream: github.com/ocaml/ocaml/... There's more to go (include functor, for example: github.com/ocaml/RFCs/p...), but it's nice to see more progress in this space.

The videos for Zurihac 2025 are online. Our own Cheng Shao, main author of GHC's Wasm backend, taught everything you need to know to build your own Haskell Wasm app in five lessons. www.youtube.com/watch?v=9zv0... What about you? What was your favourite presentation?

We're curating an exhibit on #code as culture for ‪@unesco.org‬ . Got a snippet & a story? Submit by Sept 8. https://www.softwareheritage.org/2025/07/07/code-exhibit-unesco-cfp/

Publishing crates from a #Rust workspace just got easier, thanks to the newly stabilized workspace-publishing feature that we contributed last year. Here’s how it works — and how you can use it now (blog post by Joe Neeman): www.tweag.io/blog/2025-07...

Better infrastructure, fewer surprises. We’re raising $6K for a dedicated ARM server to support #Haskell’s infrastructure (CI, backups, etc). Let’s build infra you can rely on! Every contribution helps! Donate: donorbox.org/infrastructu... Read more: discourse.haskell.org/t/infrastruc...

PSA! Please share around! Due to a limited number of submissions, we're extending the OCaml Workshop deadline by a week to July 10th AoE! Functional programmers! Heed my call! We need your submissions!!

🚨 Call for Volunteers: SPLASH/ICFP 2025 🚨 Join the team that makes it all happen! Meet the PL community, attend for free, and help run an amazing conference. Apply now 👉 tinyurl.com/splashifcp25... More info 👉 conf.researchr.org/track/icfp-s...

We are making public a #Bazel workshop we created for a client last year! Mark Karpov and Johan Herland wrote a short blog post with more information www.tweag.io/blog/2025-07...

the ICFP 2025 program is coming together! Check out our list of accepted papers: icfp25.sigplan.org/track/icfp-2... and we'll have three keynotes this year! icfp25.sigplan.org/track/icfp-2... ⬇️⬇️⬇️

Demain vendredi, lors de @lu.voxxeddays.com venez me voir en salle Amiga OS à 16h30 🎤🥳 Je vais parler builds incrémentaux 💪 caches locaux & remote, pour vos monorepos ou codebases qui mélangent plusieurs languages. Avec des outils open-source comme #bazel #pants ou #buck2

Blog post: Indexing Hackage: Glean vs. hiedb simonmar.github.io/posts/2025-0...