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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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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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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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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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. -
Gemini 3 and 200+ AI Models on One PlatformBuild generative AI apps with Vertex AI. Switch between models without switching platforms.
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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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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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Extism
The Universal Plug-in System. Extend anything with WebAssembly
Extism is a plug-in system for everyone. We've carefully designed it to be flexible, fitting into codebases of all shapes and sizes, but opinionated enough so that things Just Work™ the way they should. Extism's goal is to make all software programmable. You can use Extism in your codebase, regardless of the programming language. We support several environments through our official Host SDKs, and are adding more language support all the time. A plug-in system is software that enables your users or customers to add some logic into certain points in your application. You decide where this logic runs, and your users decide what the plug-in does. Many engineering teams face an ever-growing list of feature requests, often exceeding their bandwidth several times over. How can you ever keep up? Making your product extensible by its end-users is a great way to move some of those features outside the core, and empower customers to make your software more useful for them. -
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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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Stack
The Haskell Tool Stack
Stack is a cross-platform build tool for Haskell projects that simplifies dependency management, project setup, and reproducible builds. It provides curated package sets (Stackage), isolated project environments, and consistent tooling for compiling and testing Haskell applications. Stack streamlines workflows for developers by automating many parts of the Haskell toolchain, making it easier to get started and maintain complex codebases. It supports integration with GHC (Glasgow Haskell Compiler) and Hackage. -
MongoDB Atlas runs apps anywhereMongoDB Atlas gives you the freedom to build and run modern applications anywhere—across AWS, Azure, and Google Cloud. With global availability in over 115 regions, Atlas lets you deploy close to your users, meet compliance needs, and scale with confidence across any geography.
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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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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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Matterhorn
A feature-rich Unix terminal client for the Mattermost chat system
Matterhorn is a terminal client for the Mattermost chat system. We provide pre-built binary releases for some platforms. Please see the release list to download a binary release for your platform that matches your server version. When you run Matterhorn you'll be prompted for your server URL and credentials. To connect, just paste your web client's Mattermost URL into the Server URL box and enter your credentials. See the Matterhorn User Guide on the details for providing each kind of supported credentials. For most of our binary releases, no additional packages need to be installed; they should just work out of the box. But here are some additional requirements that may apply for your platform. Matterhorn version strings will be of the form ABBCC.X.Y where ABBCC corresponds to the lowest Mattermost server version expected to be supported by the release. For example, if a release supports Mattermost server version 1.2.3, the ABBCC portion of the matterhorn version will be 10203. -
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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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Cryptol
Cryptol: The Language of Cryptography
Cryptol is a domain-specific language (DSL) for specifying and verifying cryptographic algorithms. Developed by Galois, Cryptol provides a high-level mathematical syntax for describing cryptographic primitives and enables formal verification of algorithm properties. It is used in academic, research, and defense sectors to validate correctness and security through symbolic execution and model checking, ensuring critical cryptographic code is free of design flaws. -
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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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GHC (Glasgow Haskell Compiler)
Mirror of the Glasgow Haskell Compiler
GHC (Glasgow Haskell Compiler) is the leading open-source compiler and interactive environment for the Haskell programming language, supporting the Haskell 2010 standard plus numerous language extensions. It compiles to native machine code (via LLVM or C), and includes the interactive GHCi REPL. For full information on building GHC, see the GHC Building Guide. Here follows a summary - if you get into trouble, the Building Guide has all the answers. For building library documentation, you'll need Haddock. To build the compiler documentation, you need Sphinx and Xelatex (only for PDF output). -
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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. -
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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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Hasura GraphQL Engine
Blazing fast, instant realtime GraphQL APIs on your DB
Hasura is an open-source product that accelerates API development by 10x by giving you GraphQL or REST APIs with built-in authorization on your data, instantly. Run Hasura, locally or in the cloud, and connect it to your new or existing databases to instantly get a production-grade GraphQL API. Developers and architects love Hasura because it takes no time to get started, doesn’t need them to be a GraphQL expert upfront, and saves their teams months of recurring effort in building, shipping, and maintaining their APIs. Hasura’s built-in RLS style authorization engine allows you to conveniently specify authorization rules at a model level, and safely expose the GraphQL API to developers inside or outside your organization. Hasura’s authz engine is enabling agile teams in fast-growing startups as well as powering mission-critical data access in highly regulated environments such as Fortune 500 healthcare, financial services and US federal agencies. -
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SimpleXMQ
A reference implementation of the SimpleX Messaging Protocol
A reference implementation of the SimpleX Messaging Protocol for simplex queues over public networks. SimpleXMQ is a message broker for managing message queues and sending messages over a public network. It consists of an SMP server, SMP client library, and SMP agent that implements SMP protocol for client-server communication and SMP agent protocol to manage duplex connections via simplex queues on multiple SMP servers. SMP protocol is inspired by Redis serialization protocol, but it is much simpler - it currently has only 10 client commands and 8 server responses. -
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dhall-haskell
Maintainable configuration files
Maintainable configuration files. Navigate to each package's directory for their respective READMEs. You can download pre-built binaries for Windows, OS X and Linux on the release page. You can then click the "Help" button in the bottom right corner, which will show you a nix-env command that you can run to install the prebuilt executable. You will probably want to use the shared caches hosted at cache.dhall-lang.org and dhall.cachix.org when doing Nix development. This is not required, but this will save you a lot of time so that you don't have to build as many dependencies from scratch the first time. If you prefer installing the binaries locally in a nix shell environment instead, just run nix-shell in the top-level directory. This option provides additional flexibility with respect to overriding some of the default parameters (e.g. the compiler version), which makes it particularly useful for developers. -
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hledger
Robust, fast, intuitive plain text accounting tool with CLI
hledger is fast, reliable, free, multicurrency double-entry accounting software that runs on unix, mac, windows, and the web. With it you can track money, investments, cryptocurrencies, time, or any other quantifiable commodity; with a future-proof plain text file format, version control for your changes, and without needing any cloud service or vendor. Developed continuously since 2007, hledger is licensed under GNU GPLv3+, written in Haskell, and thoroughly tested, with $100 bounties for regressions reported. Currently, three user interfaces are provided out of the box: a powerful command line UI (hledger), a quick terminal UI (hledger-ui), and a simple web UI (hledger-web). -
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miso
A tasty Haskell front-end framework
Miso is a small, production-ready, "isomorphic" Haskell front-end framework for quickly building highly interactive single-page web applications. It features a virtual-dom, recursive diffing / patching algorithm, attribute and property normalization, event delegation, event batching, SVG, Server-sent events, Websockets, type-safe servant-style routing and an extensible Subscription-based subsystem. Inspired by Elm, Redux and Bobril. Miso is pure by default, but side effects (like XHR) can be introduced into the system via the Effect data type. Miso makes heavy use of the GHCJS FFI and therefore has minimal dependencies. Miso can be considered a shallow embedded domain-specific language for modern web programming. -
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patat
Terminal-based presentations using Pandoc
patat (Presentations Atop The ANSI Terminal) is a small tool that allows you to show presentations using only an ANSI terminal. It does not require ncurses. Leverages the great Pandoc library to support many input formats including Literate Haskell. Supports smart slide splitting. Slides can be split up into multiple fragments. There is a live reload mode. Theming support including 24-bit RGB. Auto advancing with configurable delay. Optionally re-wrapping text to terminal width with proper indentation. Syntax highlighting for nearly one hundred languages generated from Kate syntax files. Experimental images support. Supports evaluating code snippets and showing the result. Written in Haskell. -
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Carp
A functional, systems programming language with linear types
Carp is a statically typed, functional programming language designed for real-time and systems programming. It features a Lisp-like syntax, strong compile-time checks, and linear type semantics that ensure memory safety without a garbage collector. Carp targets C as its backend, generating performant and predictable native code while offering functional abstractions and interactive development via REPL.
