Open-source type-system software

231 open-source libraries, tools and applications tagged type-system, ranked by how closely type-system is their primary purpose, then by adoption and maintenance health. Each entry links to a page with sources, use cases and when to choose or avoid it.

231 products, primary matches first, then adoption-weighted; health v2 shown.

Product	Health v2	Stars	Maturity
learnhouse/learnhouse LearnHouse is a next-generation open-source learning management system (LMS) for creating, sharing, and selling educational content. It com…	100	2404	active
matz/spinel Spinel is an ahead-of-time compiler that translates Ruby source code into standalone native executables via whole-program type inference an…	70	2265	active
JoshuaKGoldberg/TypeStat TypeStat is a CLI utility that converts JavaScript files to TypeScript and improves type annotations in existing TypeScript code. It applie…	79	2253	active
Solargraph Solargraph is a Ruby language server implementing the Language Server Protocol, providing intellisense, context-aware autocompletion, inlin…	76	2009	active
dynamodb-toolbox/dynamodb-toolbox DynamoDB-Toolbox is a lightweight, type-safe query builder and abstraction layer over the AWS DynamoDB Document Client for TypeScript. It p…	93	2002	active
Servant Servant is a Haskell DSL for describing web APIs at the type level, from which servers, clients, mocks, and documentation can be derived. I…	76	1967	active
tsrpc/tsrpc TSRPC is a TypeScript RPC framework providing runtime type checking and binary serialization derived directly from TypeScript types, withou…	60	1937	active
graphql-hive/graphql-scalars A TypeScript library of custom GraphQL scalar types (e.g., DateTime, EmailAddress, UUID, BigInt, URL) for building precise, type-safe Graph…	90	1931	stable
MadAppGang/dingo Dingo is a meta-language for Go that adds Result types, error propagation with ?, pattern matching, sum types, tuples, and safe navigation,…	67	1916	active
spatie/laravel-data A Laravel package for creating rich, typed data objects that can replace form requests, API transformers, and TypeScript definitions. Data …	88	1794	stable
JetBrains/MPS JetBrains MPS is an open-source meta-programming system (language workbench) for designing domain-specific languages with a complete develo…	77	1660	stable
jeffijoe/typesync TypeSync is a CLI tool that scans your package. and installs missing TypeScript type definition (@types) packages for your dependencies. It…	57	1587	active
ivov/lisette Lisette is a small programming language inspired by Rust that compiles to readable Go, featuring Hindley-Milner type inference, algebraic d…	78	1554	active
encode/apistar API Star is a Python toolkit for working with OpenAPI and Swagger schemas, providing schema validation, static API documentation generation…	10	5535	maintenance
vue-vine/vue-vine Vue Vine is an alternative style for writing Vue.js components that allows multiple components in a single TypeScript file, as a parallel a…	82	1444	active
py2many/py2many py2many is a Python-based source-to-source transpiler that converts Python code into multiple statically-typed languages including Rust, C+…	84	1330	active
RobinBlomberg/kysely-codegen A CLI tool that generates Kysely TypeScript type definitions by introspecting your database schema. It supports PostgreSQL, MySQL, SQLite, …	60	1241	active
CakeML/cakeml CakeML is a functional programming language based on a substantial subset of Standard ML, together with a formally verified compiler that i…	92	1204	active
slang slang is a fast, highly compliant SystemVerilog frontend library providing lexing, parsing, type checking, and elaboration, plus a CLI tool…	91	1168	active
Contentlayer Contentlayer is a content SDK that validates and transforms Markdown, MDX, and CMS content into type-safe JSON data you can import directly…	23	3539	maintenance
stepci/garph Garph is a fullstack GraphQL framework for TypeScript that lets you build GraphQL APIs with a tRPC-style schema builder and no codegen. It …	31	1312	maintenance
MLstate/opalang Opa is a functional programming language for web development that compiles to JavaScript, letting developers write frontend and backend cod…	23	1263	maintenance
vercel-labs/zerolang Zerolang is an experimental programming language where a semantic graph serves as the program database, designed so AI agents author code v…	73	5380	experimental
leostera/caramel Caramel is a functional programming language that compiles OCaml-style source code to run on the Erlang VM (BEAM), combining OCaml's type s…	10	1106	maintenance
koka-lang/koka Koka is a strongly typed functional programming language with a polymorphic effect type system and algebraic effect handlers, developed as …	89	4104	experimental
WeaveMindAI/weft Weft is a programming language (currently a POC) where LLMs, humans, APIs, and infrastructure are first-class primitives for building AI or…	67	1989	experimental
evincarofautumn/kitten Kitten is a statically typed, stack-based concatenative programming language with Hindley-Milner type inference and an effect/permission sy…	32	1175	experimental
zesterer/tao Tao is a statically-typed functional programming language implemented in Rust, featuring generics, typeclasses, sum types, pattern matching…	34	1162	experimental
microsoft/BosqueLanguage Bosque is an experimental programming language from Microsoft combining functional semantics with block-based syntax, designed for regulari…	10	5203	abandoned
samdenty/gqless gqless is a TypeScript GraphQL client that lets you query GraphQL APIs by simply accessing typed objects, generating queries automatically …	23	3656	abandoned
move-language/move The original home of the Move programming language, a Rust-based language and toolchain for safe smart-contract development on blockchains.…	10	2328	abandoned