10 Haskell Open-Source Projects

Yulia Gavrilova
Article by Yulia Gavrilova
October 23rd, 2019
3 min read

Exploring Haskell open-source projects can teach you a lot about functional programming. They help you to grasp the syntax of the language and see how real programming tasks are solved even if you have zero working experience. That is why we’ve chosen 10 popular programs from GitHub written in Haskell for you to study and enjoy.

10 Haskell open-source projects worth studying


git annex haskell open source

git-annex enables you to manage files with Git without actually having to check in the file contents. It’s handy when one has to deal with large files (Git might not be able to easily handle these because of memory, time, or disk space limitations ). git-annex supports both a command line and a folder synchronizer mode.


Pandoc is a free Haskell library that converts one markup format to another. It also includes a command-line tool. Some of the formats this library supports are commonmark, docx, epub, fb2, gfm and so on. It can also create HTML or PDF (via LaTeX). Pandoc usually tries to keep the structure of the original document, but some elements like complex tables might not fit into the Pandoc’s document format.

Cardano SL

cardano sl serokell

Cardano Settlement Layer is a cryptographic currency developed by Serokell in collaboration with partners. It implements the Ouroboros PoS protocol. Cardano SL provides an elegant solution for a settlement layer of a blockchain platform that increases efficiency and security.


simple symbol search for latex

This little program simplifies symbol search for those who work with LaTeX. The user just needs to draw a sign in a special window to get a hint. This saves a lot of time, and if you want to, you can contribute to it through the GitHub open repository.

If you’re interested to learn more about the latest trends in programming, read our post about Tagless Final.


ShellCheck is a tool for static analysis of shell scripts. The program synchronizes with the latest versions on Git. Its purpose is to:

  • point out typical beginner’s syntax mistakes that provoke cryptic error messages;
  • solve problems with semantics;
  • reveal subtle caveats and pitfalls that cause the script’s failure.


darcs version control haskell

Darcs is a version control system like Git but written in Haskell. The interface is simpler than Git, which might be appreciated by beginners.


hledger is a personal resource tracker that runs on Unix, Mac or Windows. It’s meant to be a free and efficient alternative to accounting apps such as Quicken or GnuCash.

Hledger features:

  • A command-line tool. One can edit data in a text file, and Hledger will automatically form reports in various forms, like graphs and tables.
  • Zero set-up web app. It’s possible to review the data in the browser.
  • Open-source Haskell library. You can customize the app by writing your own hledger-compatible scripts and applications. Use the extensive library if needed.


legacy code translator

Need to move some legacy code from C to Rust? Corrode, the automatic C-to-Rust translator can help you with that.

It partially automates moving code that was implemented in C, but you will still need to modify the output to match Rust’s specific features and idioms.


PostgREST is a tool that serves a fully RESTful API from any existing PostgreSQL database, saving you time on writing your own API. It also states among its advantages that it is “cleaner, faster, and more standards-compliant than anything you would likely write from scratch”.


membrain is a Haskell library with a type-safe memory data type. Its purpose is to make programmers’ lives easier when they work with memory units. For example, to simplify the definition of different units without fearing to forget to multiply or divide them, combine different units and safely convert between them.

The project was created by Kowainik - a small company that cares about its open-source contributions.

If you would like to contribute to the list and share your favorite one, drop us a line! Also, if you want to progress as a Haskeller, check out our post with valuable resources for Haskell programmers.

10 Haskell Open-Source Projects
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