Open Source Haskell Software
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Haskell Software
Browse free open source Haskell Software and projects below. Use the toggles on the left to filter open source Haskell Software by OS, license, language, programming language, and project status.
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Zenflow- The AI Workflow Engine for Software DevsZenflow is the AI workflow engine built for real teams. Parallel agents plan, code, test, and verify in one workflow. With spec-driven development and deep context, Zenflow turns requirements into production-ready output so teams ship faster and stay in flow.
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Pandoc
The universal markup converter
Pandoc is a universal document converter able to convert files from a multitude of markup formats into another. With Pandoc, you have a swiss-army knife of a converter, able to convert practically any markup format into any other. Pandoc contains a Haskell library for conversions as well as a command-line tool that uses this library. It can convert to and from just about anything-- lightweight markup formats, HTML formats, documentation formats, ebooks, TeX formats, word processor formats and so much more. It understands several useful markdown syntax extensions, such as document metadata, footnotes, tables, and more. If you want strict markdown compatibility however, these extensions can be turned off. Pandoc is no doubt powerful and customizable, but it is important to note that its intermediate representation of a document is less expressive than many of the formats, so it may not produce perfect conversions every time. -
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FreeArc combines best 7-zip and RAR features: auto-selected LZMA/PPMD/Multimedia compression, 1gb dictionary, exe/dict/delta data filters, updatable solid archives, SFXes, recovery record, AES+Twofish+Serpent encryption, Linux support and much more...
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SimpleX
The first messaging platform operating without user identifiers
Other apps have user IDs: Signal, Matrix, Session, Briar, Jami, Cwtch, etc. SimpleX does not, not even random numbers. This radically improves your privacy. The video shows how you connect to your friend via their 1-time QR-code, in person or via a video link. You can also connect by sharing an invitation link. Temporary anonymous pairwise identifiers SimpleX uses temporary anonymous pairwise addresses and credentials for each user contact or group member. It allows to deliver messages without user profile identifiers, providing better meta-data privacy than alternatives. Many communication platforms are vulnerable to MITM attacks by servers or network providers. To prevent it SimpleX apps pass one-time keys out-of-band when you share an address as a link or a QR code. Double-ratchet protocol. OTR messaging with perfect forward secrecy and break-in recovery. NaCL cryptobox in each queue to prevent traffic correlation between message queues if TLS is compromised. -
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Kmonad
An advanced keyboard manager
KMonad is a cross-platform, advanced keyboard remapping tool written in Haskell. It provides low-level key control, supporting layers, tap-hold combos, multi-tap, macros, and more—even for keyboards without firmware-level customization. -
Grafana: The open and composable observability platformGrafana is the open source analytics & monitoring solution for every database.
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ShellCheck
A static analysis tool for shell scripts
ShellCheck is a GPLv3 tool that provides warnings and possible suggestions for bash/sh shell scripts. ShellCheck finds bugs in your shell scripts. You can cabal, apt, dnf, pkg or brew install it locally right now. ShellCheck highlights and clarifies typical beginner's syntax mistakes and issues that cause a shell to give a cryptic error message. It shows typical intermediate level semantic problems that cause a shell to behave in a abnormally and counter-intuitively. It can also discover ssubtle caveats, corner cases and pitfalls that may cause an user's working script to fail under probable future circumstances. ShellCheck.net is always synchronized to the latest git version, and is the simplest way to give ShellCheck a go. -
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PostgREST
REST API for any Postgres database
PostgREST is a standalone web server that turns your PostgreSQL database directly into a RESTful API. The structural constraints and permissions in the database determine the API endpoints and operations. Using PostgREST is an alternative to manual CRUD programming. Custom API servers suffer problems. Writing business logic often duplicates, ignores or hobbles database structure. Object-relational mapping is a leaky abstraction leading to slow imperative code. The PostgREST philosophy establishes a single declarative source of truth: the data itself. It’s easier to ask PostgreSQL to join data for you and let its query planner figure out the details than to loop through rows yourself. It’s easier to assign permissions to db objects than to add guards in controllers. (This is especially true for cascading permissions in data dependencies.) It’s easier to set constraints than to litter code with sanity checks. -
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tetris
A terminal interface for Tetris
A terminal interface for Tetris. Installation on MacOS and Linux is outlined below. Windows support is questionable, but you can try to install from source. The default game is run by simply executing the tetris command. If the unicode characters look a bit wonky in your terminal, you can also run. People seem to have varying levels of success with the linux binary. Please note that it is compiled dynamically and hence should not be expected to work on most distros. This code is built on top of brick which makes building terminal user interfaces very accessible. -
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Clash
Haskell to VHDL/Verilog/SystemVerilog compiler
Clash is a functional hardware description language that borrows both its syntax and semantics from the functional programming language Haskell. It provides a familiar structural design approach to both combinational and synchronous sequential circuits. The Clash compiler transforms these high-level descriptions to low-level synthesizable VHDL, Verilog, or SystemVerilog. Clash is an open-source project, licensed under the permissive BSD2 license, and actively maintained by QBayLogic. The Clash project is a Haskell Foundation affiliated project. Clash is built on Haskell which provides an excellent foundation for well-typed code. Together with Clash's standard library it is easy to build scalable and reusable hardware designs. Load your designs in an interpreter and easily test all your component without needing to setup a test bench. Although Clash offers many features, you sometimes need to directly access VHDL, Verilog, or SystemVerilog directly. -
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Echidna
Ethereum smart contract fuzzer
Echidna is a weird creature that eats bugs and is highly electrosensitive (with apologies to Jacob Stanley) More seriously, Echidna is a Haskell program designed for fuzzing/property-based testing of Ethereum smarts contracts. It uses sophisticated grammar-based fuzzing campaigns based on a contract ABI to falsify user-defined predicates or Solidity assertions. We designed Echidna with modularity in mind, so it can be easily extended to include new mutations or test specific contracts in specific cases. Optional corpus collection, mutation and coverage guidance to find deeper bugs. Powered by Slither to extract useful information before the fuzzing campaign. Source code integration to identify which lines are covered after the fuzzing campaign. Curses-based retro UI, text-only or JSON output. -
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koka
Koka language compiler and interpreter
Koka is a strongly typed functional-style language with effect types and handlers. The core of Koka consists of a small set of well-studied language features, like first-class functions, a polymorphic type- and effect system, algebraic data types, and effect handlers. Each of these is composable and avoid the addition of “special” extensions by being as general as possible. Koka tracks the (side) effects of every function in its type, where pure and effectful computations are distinguished. The precise effect typing gives Koka rock-solid semantics backed by well-studied category theory, which makes Koka particularly easy to reason about for both humans and compilers. Effect handlers let you define advanced control abstractions, like exceptions, async/await, or probabilistic programs, as a user library in a typed and composable way. Perceus is an advanced compilation method for reference counting. -
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Cardano Node
The core component that is used to participate in a Cardano
Cardano Node is the core software that powers the Cardano blockchain, a decentralized, proof-of-stake platform for smart contracts and digital assets. Developed in Haskell, the node allows participation in Cardano’s network by validating transactions, producing blocks, and maintaining the ledger. It supports Shelley, Goguen, Basho, and other phases of Cardano’s roadmap, and plays a crucial role in network security and consensus. The node is configurable for different use cases, including running full nodes, relay nodes, or stake pool operators. -
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Gifcurry
The open-source, Haskell-built video editor for GIF makers
The open-source, Haskell-built video editor for GIF makers. Gifcurry is the open-source video editor for GIF makers. It's built with Haskell and works on Linux, Mac, and most likely Windows. There is both a graphical and command line interface. Gifcurry edits your GIFs or videos and turns them into videos or GIFs. You can crop, trim, seek, add text, pick a font, alter the duration, change the size, set the FPS, tweak the color count, enable dithering, import subtitles, and save your creation as either a GIF or video. Before you download Gifcurry, make sure your machine has GTK+, GStreamer, FFmpeg, and ImageMagick. Linux users can download the AppImage or the prebuilt binaries. If you'd rather install it, you can do so via pacman (Arch) or snap. If you're really courageous, you can build it from source. -
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Wasp
A programming language that understands what a web app is
Wasp (Web Application Specification Language) is a declarative DSL (domain-specific language) for developing, building and deploying modern full-stack web apps with less code. Concepts such as app, page, user, login, frontend, production, etc. are baked into the language, bringing a new level of expressiveness and allowing you to get more work done with fewer lines of code. While describing high-level features with Wasp, you still write the rest of your logic in your favorite technologies (currently React, NodeJS, Prisma). Wasp is in alpha and is therefore likely to change a lot, have bugs and miss important features. Due to its expressiveness, you can create and deploy a production-ready web app from scratch with very few lines of concise, consistent, declarative code. When you need more control than Wasp offers, you can write code in existing technologies such as js/html/css/... and combine it with Wasp code! -
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CodeWorld
Educational computer programming environment using Haskell
CodeWorld is an educational programming environment that uses a Haskell-inspired language to teach computational thinking through graphics and interactive animation. The web-based IDE provides immediate visual feedback: students write code that draws shapes, composes pictures, and responds to events to build simple games and simulations. Its API emphasizes mathematics and geometry rather than low-level UI details, making it approachable for classrooms and self-learners. Projects run in the browser, leveraging a compiler pipeline that turns the high-level code into JavaScript so no installation is required. The platform includes project management, sharing, and classroom features so instructors can distribute examples and students can submit work. By constraining the language surface and curating libraries, CodeWorld balances the expressive power of functional programming with the simplicity needed for first-time programmers. -
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FOSSA CLI
Fast, portable and reliable dependency analysis for any codebase
FOSSA CLI is a command-line tool that scans your codebase to identify open-source dependencies and their associated licenses and vulnerabilities. It integrates into CI/CD pipelines to provide automated compliance checks, license audits, and security analysis. Designed for enterprise software teams, FOSSA CLI helps enforce open-source policies at scale and provides accurate, automated insights into third-party software usage through deep analysis of transitive dependencies and ecosystem-specific configurations. -
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ImplicitCAD
A math-inspired CAD program in haskell. CSG, bevels, and shells
ImplicitCAD is a programmatic CAD program, implemented in Haskell. Unlike traditional CAD programs, programmatic CAD programs use text descriptions of objects, as in programming. Concepts like variables, control structures and abstraction are used, just as in programming. With the explosion of 3D printing, designing 3D objects has become an even more important problem. And it's a complicated one. We need to design complicated objects that precisely interface with each other. And often we don't want to just design a single object, but classes of objects, parameterized by variables. And we need to do this in collaboration. Generally, objects in programmatic CAD are built with Constructive Solid Geometry or CSG. Unions, intersections and differences of simpler shapes slowly build the object. ImplicitCAD supports all this and much more! For example, it provides rounded unions so that one can have smooth interfaces between objects. -
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Plutus
The Plutus language implementation and tools
Plutus is the smart contract development framework for the Cardano blockchain, created using Haskell. It provides the core infrastructure for writing, testing, and deploying secure, deterministic smart contracts on the Cardano platform. Plutus includes a custom functional language (Plutus Core), a higher-level embedded DSL (Plutus Tx) for writing contracts in Haskell, and an off-chain infrastructure for managing interactions. It ensures strong correctness guarantees through formal verification and functional programming paradigms. -
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Tidal
Pattern language
Tidal Cycles (or just Tidal for short) is software for making patterns with code, whether live coding music at algoraves or composing in the studio. It includes a simple and flexible notation for rhythmic sequences and an extensive library of patterning functions for combining and transforming them. This allows you to quickly create complex patterns from simple ingredients. By default, sound is made with the featureful SuperDirt synth/sampler, but you can control other synths using Open Sound Control (OSC) or MIDI. Whether you're using SuperDirt or a synth, every filter and effect can be manipulated independently with Tidal patterns. Tidal is embedded in the Haskell language, although you don't have to learn Haskell to learn Tidal. You can learn Tidal through experimentation and play, most Tidal coders have little or no experience in software engineering. -
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Wire Server
Wire back-end services
Modern day communication meets the most advanced security and superior user experience. Protect your privacy and data like never before. Secure messaging, conferencing, file-sharing and more through end-to-end encryption for cloud, private cloud and On-Premises. All messaging on Wire uses end-to-end encryption (E2EE), giving users a strong degree of privacy and security. Wire is 100% open source with its code available on GitHub, independently audited and ISO, CCPA, GDPR, SOX-compliant. Wire can be deployed on Wire's Cloud, your cloud server, or your own on-premises server and all features can be used across web, mobile, and PC. With Conferencing, you can talk to co-workers, guests, external vendors together in one single place. All files are fully E2EE and are continually stored on a server of choice, without a timeout. -
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nixfmt
The official formatter for Nix code
nixfmt is a code formatter for the Nix expression language, aiming to provide consistent and idiomatic formatting for Nix files. It is written in Haskell and designed to be fast, predictable, and fully automatic with zero configuration. nixfmt helps Nix developers maintain readability and code consistency across large codebases, facilitating collaboration and version control workflows. -
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BSC
Bluespec Compiler (BSC)
BSC is the open source compiler toolchain for Bluespec SystemVerilog, a high-level, rule-based hardware design language. It translates Bluespec descriptions into synthesizable Verilog, letting developers bring typed, modular abstractions into mainstream FPGA/ASIC flows. The compiler performs scheduling of atomic rules, elaborates parameterized modules, and enforces interface contracts, producing predictable RTL that integrates with existing EDA tools. A companion simulator enables fast functional execution and debugging before handing designs to traditional verification and synthesis stages. The ecosystem includes standard libraries, FIFOs, interfaces, and utilities that encourage reuse and clean separation of datapaths and control. By raising the abstraction for hardware architecture while preserving efficient output, BSC helps teams explore complex designs—such as RISC-V cores or accelerators—more productively. -
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Brick
A declarative Unix terminal UI library written in Haskell
Brick is a Haskell terminal user interface (TUI) programming toolkit that enables developers to build rich, responsive terminal applications via a declarative model: you define a pure function that renders the UI from application state and supply state transition logic to handle events. brick exposes a declarative API. Unlike most GUI toolkits which require you to write a long and tedious sequence of widget creations and layout setup, brick just requires you to describe your interface using a set of declarative layout combinators. Event-handling is done by pattern-matching on incoming events and updating your application state. Under the hood, this library builds upon vty, so some knowledge of Vty will be necessary to use this library. Brick depends on vty-crossplatform, so Brick should work anywhere Vty works (Unix and Windows). Brick releases prior to 2.0 only support Unix-based systems. -
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Greenclip
Simple clipboard manager to be integrated with rofi
Greenclip is a lightweight clipboard manager designed for Wayland and X11 environments on Linux. It integrates seamlessly with Rofi or other application launchers, allowing users to access and paste clipboard history entries quickly. Greenclip stores clipboard content persistently and can be configured to manage how many entries are saved, offering a minimalistic yet effective solution for power users and Linux enthusiasts. -
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Obelisk
Functional reactive web and mobile applications, with batteries
Functional reactive web and mobile applications, with batteries included. Obelisk's goal is to represent a cohesive, highly-curated set of choices that Obsidian Systems has made for building these types of applications in a way that is extremely fast but does not compromise on production readiness. Obelisk allows you to build high-quality web and mobile applications very quickly using Reflex. In minutes you can go from an empty directory to an interactive application that works on web, iOS, and Android, all sharing the same Haskell codebase! Obelisk's development environment also enables extremely rapid development and feedback. You can take advantage of Haskell's type system across the frontend and backend boundary. This means changes to your backend that would break your frontend are immediately detected during development and vice versa. Obelisk uses Haskell's compiler to give you a complete "TODO list" of what needs to be updated. -
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PureScript
A strongly-typed language that compiles to JavaScript
Compile to readable JavaScript and reuse existing JavaScript code easily. An extensive collection of libraries for development of web applications, web servers, apps and more. Excellent tooling and editor support with instant rebuilds. An active community with many learning resources. Build real-world applications using functional techniques and expressive types, such as: Algebraic data types and pattern matching. Row polymorphism and extensible records. Higher kinded types and type classes with functional dependencies, as well as higher-rank polymorphism. Precompiled binaries are available for OSX, Linux, and Windows. The Pursuit package database hosts searchable documentation for PureScript packages. The recommended build tool for PureScript is Spago, which can be installed using npm.
