Open Source Packages
Libraries, frameworks, tools, and SDKs used by the apps in this directory — scored the same way as the apps themselves.
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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.
typescript-eslint
The official meta-package bundling the TypeScript ESLint parser, plugin, and rule presets behind a single typed config() helper.
Playwright
Cross-browser end-to-end web testing and browser automation with a single API for Chromium, Firefox, and WebKit.
React Testing Library
Simple and complete React DOM testing utilities that encourage good testing practices.
jest-dom
Custom Jest matchers for asserting on the state of the DOM in your tests.
jest
Delightful JavaScript testing with zero-config setup, snapshots, mocking, and coverage
user-event
Simulates the full sequence of real browser events so Testing Library tests behave the way an actual user does.
Marked
A fast, low-level Markdown compiler that parses CommonMark and GFM into HTML in Node.js, browsers, or the CLI.
Requests
The elegant, human-friendly HTTP library that made Python's most-used API for talking to the web.
Pydantic
Data validation and settings management using Python type hints, backed by a Rust core.
testify
The essential Go toolkit for assertions, mocks, and structured test suites.
js-yaml
A fast, complete YAML 1.2 and 1.1 parser and serializer for JavaScript.
pytest
The Python testing framework that makes writing small tests easy and scales to complex functional test suites.
yaml
A definitive TypeScript parser and stringifier for YAML, supporting 1.1 and 1.2 with comment and CST access.
Commander.js
The complete, battle-tested framework for building Node.js command-line interfaces.
DOM Testing Library
Simple, framework-agnostic DOM query utilities that test your UI the way real users interact with it.
HTTPX
A next-generation HTTP client for Python with sync, async, and HTTP/2 support
Storybook
The industry-standard workshop for building, documenting, and testing UI components in isolation, across every major frontend framework.
Uvicorn
A lightning-fast ASGI server for Python, built on uvloop and httptools.
NumPy
The fundamental N-dimensional array library powering Python's scientific computing stack.
PyYAML
A full-featured YAML parser and emitter for Python, with C-accelerated bindings
FastAPI
A modern, high-performance Python web framework for building APIs with automatic validation, serialization, and interactive docs.
python-dotenv
Load environment variables from a .env file into Python's os.environ, the standard way to keep 12-factor config out of your code
Oxlint
Rust-based JavaScript/TypeScript linter that runs 50-100x faster than ESLint, with zero configuration required.