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

96Health
Framework PyPI

pytest

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

14,543
MIT
Used by 100
95Health
Framework Cargo

Tokio

The async runtime powering most of Rust's networked, concurrent, and I/O-bound applications.

33,257
MIT
Used by 96
91Health
Tool PyPI

Uvicorn

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

10,993
BSD 3
Used by 83
91Health
Framework PyPI

FastAPI

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

102,676
MIT
Used by 78
90Health
Tool npm

SWC

Rust-based JavaScript/TypeScript compiler, a drop-in super-fast alternative to Babel

34,208
Apache 2.0
Used by 56
90Health
Tool PyPI

Ruff

An extremely fast Python linter and code formatter, written in Rust, built as a drop-in replacement for Flake8, Black, isort, and dozens of plugins.

49,811
MIT
Used by 46
91Health
Framework Cargo

Tauri

Build tiny, fast, and secure desktop and mobile apps with a Rust backend and a web frontend.

111,435
Apache 2.0
Used by 42
95Health
Framework PyPI

aiohttp

Asynchronous HTTP client and server framework for Python's asyncio, covering both API calls and building web/WebSocket services.

16,561
Apache 2.0
Used by 40
95Health
Framework PyPI

Transformers

State-of-the-art pretrained models for text, vision, audio, and multimodal inference and training.

166,736
Apache 2.0
Used by 38
88Health
Tool PyPI

Gunicorn

A fast, lightweight pre-fork WSGI and ASGI HTTP server for running Python web apps in production on UNIX.

10,686
MIT
Used by 33
78Health
Tool npm

openapi-typescript

Generate type-safe TypeScript types directly from your OpenAPI 3.0 and 3.1 schemas.

8,381
MIT
Used by 33
83Health
Tool PyPI

mypy

Optional static type checker that catches Python bugs before you run your code

20,651
MIT
Used by 30
81Health
Framework PyPI

Flask

A lightweight WSGI web framework for Python that scales from a single file to complex applications.

74,802
BSD 3
Used by 28
92Health
Framework Cargo

axum

Ergonomic and modular HTTP routing and request-handling framework for Rust, built on Tokio, Hyper, and Tower.

27,254
MIT
Used by 28
89Health
Tool PyPI

Alembic

Database migrations tool for SQLAlchemy with autogenerate and transactional DDL

4,413
MIT
Used by 27
89Health
Framework PyPI

Typer

Typer is a Python library for building CLI applications, using type hints to generate arguments, options, validation, help text, and shell completion automatically.

20,033
MIT
Used by 26
87Health
Framework PyPI

Django

The high-level Python web framework that turns database models into secure, working web applications in record time.

91,218
BSD 3
Used by 24
92Health
Framework PyPI

LangChain

The most widely adopted Python framework for building LLM-powered agents and applications

147,170
MIT
Used by 21
94Health
Framework PyPI

Starlette

A lightweight ASGI framework/toolkit for building async web services and apps in Python

12,639
BSD 3
Used by 21
93Health
Tool npm

GraphQL Code Generator

A plugin-based CLI that generates typed code from a GraphQL schema and operations

11,262
MIT
Used by 21
92Health
Framework PyPI

LangGraph

A low-level orchestration framework for building stateful, multi-actor LLM agents as graphs

42,375
MIT
Used by 18
93Health
Tool npm

sentry-cli

Official command-line tool for uploading source maps, debug symbols, and managing releases and deploys in Sentry.

1,043
Other
Used by 17
91Health
Framework PyPI

django-rest-framework

The most widely-used toolkit for building Web APIs on top of Django, with serializers, viewsets, and a built-in browsable API.

30,191
BSD 3
Used by 15
88Health
Framework PyPI

FastMCP

The fast, Pythonic framework for building Model Context Protocol servers, clients, and apps

27,913
Apache 2.0
Used by 14

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