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

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.

28,972
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.

16,391
MIT
Used by 260
92Health
Framework npm

Playwright

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

96,127
Apache 2.0
Used by 228
74Health
Library npm

dotenv

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

20,536
Other
Used by 227
68Health
Library npm

date-fns

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

36,648
MIT
Used by 202
93Health
Library npm

jsdom

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

21,681
MIT
Used by 199
65Health
Library npm

React Testing Library

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

19,651
MIT
Used by 195
95Health
Library npm

Axios

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

109,212
MIT
Used by 190
66Health
Library npm

jest-dom

Custom Jest matchers for asserting on the state of the DOM in your tests.

4,597
MIT
Used by 165
86Health
Framework npm

Express

The fast, unopinionated, minimalist web framework for Node.js

69,454
MIT
Used by 158
94Health
Tool npm

jest

Delightful JavaScript testing with zero-config setup, snapshots, mocking, and coverage

45,457
MIT
Used by 149
94Health
SDK npm

AWS SDK for JavaScript (S3 Client)

The official modular AWS SDK v3 client for Amazon S3, with TypeScript-first APIs and streaming support.

3,666
Apache 2.0
Used by 129
83Health
Library npm

ws

A simple, blazing-fast, thoroughly tested WebSocket client and server library for Node.js.

22,804
MIT
Used by 116
79Health
Library npm

user-event

Simulates the full sequence of real browser events so Testing Library tests behave the way an actual user does.

2,326
MIT
Used by 116
95Health
Library npm

Marked

A fast, low-level Markdown compiler that parses CommonMark and GFM into HTML in Node.js, browsers, or the CLI.

37,141
MIT
Used by 112
82Health
Library PyPI

Requests

The elegant, human-friendly HTTP library that made Python's most-used API for talking to the web.

54,300
Apache 2.0
Used by 110
89Health
Library npm

sharp

High-performance Node.js image processing powered by libvips, built for fast resizing and format conversion.

32,677
Apache 2.0
Used by 109
85Health
Library npm

i18next

The internationalization framework for JavaScript, with zero runtime dependencies and a pluggable ecosystem for every environment.

8,633
MIT
Used by 109
93Health
Library PyPI

Pydantic

Data validation and settings management using Python type hints, backed by a Rust core.

28,772
MIT
Used by 102
73Health
Library Go

testify

The essential Go toolkit for assertions, mocks, and structured test suites.

26,203
MIT
Used by 102
82Health
Library npm

js-yaml

A fast, complete YAML 1.2 and 1.1 parser and serializer for JavaScript.

6,630
MIT
Used by 101
96Health
Framework PyPI

pytest

The Python testing framework that makes writing small tests easy and scales to complex functional test suites.

14,506
MIT
Used by 100
90Health
Library npm

yaml

A definitive TypeScript parser and stringifier for YAML, supporting 1.1 and 1.2 with comment and CST access.

1,691
Other
Used by 98
63Health
Framework npm

Commander.js

The complete, battle-tested framework for building Node.js command-line interfaces.

28,391
MIT
Used by 94

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