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
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
65Health
Library npm

React Testing Library

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

19,651
MIT
Used by 195
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
94Health
Tool npm

jest

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

45,457
MIT
Used by 149
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
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
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
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
69Health
Library npm

DOM Testing Library

Simple, framework-agnostic DOM query utilities that test your UI the way real users interact with it.

3,332
MIT
Used by 87
54Health
Library PyPI

HTTPX

A next-generation HTTP client for Python with sync, async, and HTTP/2 support

15,478
BSD 3
Used by 85
95Health
Tool npm

Storybook

The industry-standard workshop for building, documenting, and testing UI components in isolation, across every major frontend framework.

91,053
MIT
Used by 83
91Health
Tool PyPI

Uvicorn

A lightning-fast ASGI server for Python, built on uvloop and httptools.

10,963
BSD 3
Used by 81
96Health
Library PyPI

NumPy

The fundamental N-dimensional array library powering Python's scientific computing stack.

32,741
BSD 3
Used by 80
55Health
Library PyPI

PyYAML

A full-featured YAML parser and emitter for Python, with C-accelerated bindings

2,942
MIT
Used by 79
70Health
Library npm

Fontsource Inter

Self-host the Inter typeface with a single npm install and zero third-party font requests.

495
Other
Used by 78
90Health
Framework PyPI

FastAPI

A modern, high-performance Python web framework for building APIs with automatic validation, serialization, and interactive docs.

102,333
MIT
Used by 76
65Health
Library PyPI

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

8,876
BSD 3
Used by 72
92Health
Library npm

undici

A fast, spec-compliant HTTP/1.1 client for Node.js, built from scratch with zero runtime dependencies

7,695
MIT
Used by 70
73Health
Library Cargo

tempfile

A secure, cross-platform Rust library for temporary files and directories that clean up automatically on drop.

1,463
Other
Used by 68
98Health
Library PyPI

pandas

The Python DataFrame library for fast, flexible, and expressive data analysis and manipulation.

49,732
BSD 3
Used by 61
92Health
Library PyPI

Pillow

The friendly PIL fork that adds image processing capabilities to Python

13,812
Other
Used by 60
91Health
SDK PyPI

boto3

The official AWS SDK for Python — call every Amazon Web Services API from your code.

9,900
Apache 2.0
Used by 59
96Health
SDK PyPI

OpenAI Python SDK

The official Python library for the OpenAI REST API, generated from OpenAI's OpenAPI spec with typed sync and async clients.

31,622
Apache 2.0
Used by 57

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