Directory

Open Source Packages

Libraries, frameworks, tools, and SDKs used by the apps in this directory — scored the same way as the apps themselves.

5929 packages

All Packages

95Health
Tool npm

TypeScript

A strongly typed superset of JavaScript that compiles to clean, portable JavaScript.

111,581
Apache 2.0
Used by 504
98Health
Library npm

React

The declarative, component-based JavaScript library for building fast, interactive user interfaces on the web and in native apps.

251,734
MIT
Used by 408
98Health
Library npm

React DOM

React's official renderer for the DOM and server — createRoot, hydrateRoot, and streaming SSR in one package.

251,734
MIT
Used by 403
95Health
Tool npm

ESLint

The pluggable JavaScript and TypeScript linter that finds and fixes code problems through a fully customizable, plugin-based rule engine.

27,575
MIT
Used by 369
90Health
Library npm

Tailwind CSS

A utility-first CSS framework for rapidly building custom user interfaces without leaving your markup.

98,035
MIT
Used by 343
94Health
Tool npm

Vite

Next-generation frontend build tool with an instant dev server, lightning-fast HMR, and optimized production builds.

83,496
MIT
Used by 327
91Health
Tool npm

prettier

An opinionated code formatter that enforces consistent style across every language your project speaks.

52,379
MIT
Used by 310
93Health
Tool npm

Vitest

A blazing-fast unit testing framework powered by Vite, with Jest-compatible APIs out of the box.

17,276
MIT
Used by 297
91Health
Library npm

Zod

TypeScript-first schema validation with static type inference and zero dependencies.

44,182
MIT
Used by 278
92Health
Library npm

postcss

A CSS transformation engine that parses styles into an AST, letting JS plugins lint, prefix, and rewrite CSS — the foundation beneath Autoprefixer, Tailwind, and 200+ other tools.

28,966
MIT
Used by 277
94Health
Tool npm

typescript-eslint

The official meta-package bundling the TypeScript ESLint parser, plugin, and rule presets behind a single typed config() helper.

16,440
MIT
Used by 261
42Health
Library npm

clsx

A tiny, fast utility for conditionally constructing className strings

9,847
MIT
Used by 258
92Health
Framework npm

Playwright

Cross-browser end-to-end web testing and browser automation with a single API for Chromium, Firefox, and WebKit.

98,387
Apache 2.0
Used by 230
78Health
Library npm

dotenv

Loads environment variables from a .env file into process.env for Node.js apps.

20,550
Other
Used by 227
92Health
Library npm

lucide-react

1,700+ tree-shakeable, customizable SVG icon components for React applications

25,246
Other
Used by 222
89Health
Library npm

tailwind-merge

Merge Tailwind CSS classes without style conflicts

5,693
MIT
Used by 220
92Health
Tool npm

@vitejs/plugin-react

The official Vite plugin for React with Babel-powered Fast Refresh and JSX transforms

1,174
MIT
Used by 212
82Health
Library npm

date-fns

Modern JavaScript date utility library with 200+ pure, immutable functions

36,648
MIT
Used by 202
90Health
Library npm

jsdom

A pure-JavaScript implementation of the WHATWG DOM and HTML standards for Node.js.

21,730
MIT
Used by 200
81Health
Library npm

Autoprefixer

Parses your CSS and automatically adds vendor prefixes using real-world browser usage data from Can I Use.

22,202
MIT
Used by 198
61Health
Library npm

React Testing Library

Simple and complete React DOM testing utilities that encourage good testing practices.

19,672
MIT
Used by 196
65Health
Library npm

Lodash

A modern JavaScript utility library delivering modularity, performance, and extras for arrays, objects, and functions.

61,284
MIT
Used by 194
82Health
Library npm

class-variance-authority

A tiny TypeScript utility for building type-safe, variant-driven className APIs on top of clsx.

6,906
Apache 2.0
Used by 191
95Health
Library npm

Axios

Promise-based HTTP client for the browser and Node.js with interceptors, automatic transforms, and cancellation

109,305
MIT
Used by 190

Join founders buildingwith open source

Opinionated takes, migration guides, cost-saving tips, and insights from the open source ecosystem.

Subscribe on Substack
Join 750+ subscribers