All organizations · GSoC 2026 · Programming languages, Development tools

Haskell.org

Purely functional programming language

Haskell is an advanced, general-purpose, purely functional programming language. It has a strong, static type system with Hindley-Milner type inference. The language natively supports lazy evaluation, and lets you track side effects in the type system. This leads to a concise and declarative style of programming, which differs quite a bit from conventional languages. By controlling side effects and working with immutable data, the programmer can avoid whole classes of bugs. Haskell generally compiles to fast, native code, but it can also be compiled to other targets like JavaScript (through GHCJS) or LLVM. In Google Summer of Code, we attempt to improve not only the language, but the whole ecosystem. This includes (aside from the language itself): - Compilers - Commonly used libraries - Commonly used applications written in Haskell - Profilers, debuggers and other tools - Package managers and infrastructure We have compiled an ideas list together with long-time Haskell users, compiler contributors and researchers, and as such we believe these are important projects for the industry and academia both.

  • haskell
  • ghc
  • compilers
  • programming languages
  • functional programming
  • programming tools

Project ideas

9 ideas on its 2026 ideas page; of the 8 that state a difficulty: 5 medium, 3 hard. Sizes: 4 medium, 3 large. 3 mentors named.

  1. For project maintainers
  2. Case split plugin🔗 large hard
  3. Dynamic LSP capabilities🔗 medium medium
  4. Goto dependency definition🔗 large hard
  5. Revive the support for type-class elaboration in Liquid Haskell🔗 medium
  6. xeus-haskell - GHC/Wasm Backend Integration Prototype🔗 large hard
  7. xeus-haskell - Library Expansion and Packaging for MicroHs🔗 medium medium
  8. xeus-haskell - Precompilation and Caching for Instant Startup🔗 medium medium
  9. xeus-haskell - Interactive Widgets for Haskell Notebooks🔗 medium medium

Read the ideas page. Ideas are for scope reference; never copy one into a proposal.

History

In GSoC since 2018, 8 years. Projects per year: '18: 15, '19: 15, '20: 12, '21: 10, '22: 10, '24: 4, '25: 3, '26: 4.

On GitHub

67 repositories pushed to in the last year. Main languages: Haskell (58), TypeScript (2), C (1), CSS (1), Dockerfile (1), Emacs Lisp (1).

Links and channels

go deeper in your terminal
git-into-gsoc org "Haskell.org" --shortlist
git-into-gsoc repos "Haskell.org"
git-into-gsoc issues --org "Haskell.org"
or ask your assistant:
"Which Haskell.org repositories merge
newcomers' pull requests, and which beginner
issues are still free?"

Those commands read live data: which repositories merge outside pull requests, and which beginner issues nobody has claimed. Install in two minutes.