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

90Health
Library npm

Tailwind CSS

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

97,558
MIT
Used by 340
91Health
Tool npm

prettier

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

52,263
MIT
Used by 310
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
87Health
Library npm

tailwind-merge

Merge Tailwind CSS classes without style conflicts

5,688
MIT
Used by 218
88Health
Library npm

Autoprefixer

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

22,229
MIT
Used by 198
83Health
Library npm

class-variance-authority

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

6,888
Apache 2.0
Used by 190
82Health
Tool npm

esbuild

An extremely fast JavaScript and CSS bundler and minifier written in Go.

40,058
MIT
Used by 139
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
92Health
Tool npm

Sass

The reference Dart implementation of Sass, the mature CSS preprocessor that compiles SCSS and indented syntax to standards-compliant CSS.

4,219
MIT
Used by 108
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
34Health
Library npm

tailwindcss-animate

Tailwind CSS plugin for enter and exit animations using utility classes

3,018
MIT
Used by 100
42Health
Library npm

tw-animate-css

A pure-CSS, Tailwind CSS v4 compatible replacement for tailwindcss-animate.

802
MIT
Used by 97
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
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
60Health
Library npm

diff

A battle-tested JavaScript library for computing and applying text diffs at the character, word, line, sentence, CSS, or JSON level.

9,207
BSD 3
Used by 70
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
97Health
Framework npm

Electron

Build cross-platform desktop apps with JavaScript, HTML, and CSS on Chromium and Node.js

123,052
MIT
Used by 68

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