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
Tool PyPI

isort

Automatically sorts and organizes Python import statements

6,953
MIT
Used by 8
94Health
Library PyPI

Werkzeug

The comprehensive WSGI utility library that powers Flask and countless Python web apps.

6,879
BSD 3
Used by 8
88Health
Library PyPI

gevent

Coroutine-based concurrency for Python, built on greenlets and a fast libev/libuv event loop.

6,447
MIT
Used by 8
85Health
Library PyPI

json_repair

Repair malformed JSON from LLMs, APIs, logs, and user input — a drop-in fallback for json.loads().

5,113
MIT
Used by 8
82Health
Library PyPI

python-socketio

Python implementation of the Socket.IO realtime protocol for both servers and clients.

4,371
MIT
Used by 8
81Health
Library PyPI

Markdown

The reference Python implementation of John Gruber's Markdown, with a pluggable extension system for converting text to HTML.

4,253
BSD 3
Used by 8
89Health
Library PyPI

msgspec

A fast, zero-cost serialization and validation library for JSON, MessagePack, YAML, and TOML in Python.

4,129
BSD 3
Used by 8
69Health
Tool PyPI

flake8

The CLI linter that wraps PyFlakes, pycodestyle, and McCabe complexity checks into a single Python style and error checker.

3,823
MIT
Used by 8
49Health
Library PyPI

html2text

Converts HTML into clean, readable Markdown-formatted plain text, as both a Python library and a CLI tool.

2,173
GPL 3.0
Used by 8
88Health
Library PyPI

PyMdown Extensions

A rich extension pack for Python-Markdown adding tabs, superfences, emoji, and more

1,130
MIT
Used by 8
36Health
SDK PyPI

aioboto3

An async wrapper around boto3's high-level AWS resources, backed by aiobotocore

1,003
Apache 2.0
Used by 8
48Health
Library PyPI

Flask-CORS

Cross-Origin Resource Sharing (CORS) support for Flask applications

933
MIT
Used by 8
67Health
Library PyPI

argon2-cffi

Secure, high-level password hashing for Python using Argon2

731
MIT
Used by 8
79Health
Library npm

officeParser

Parse Office documents into a rich AST and generate Markdown, HTML, PDF, or RAG chunks

551
MIT
Used by 8
67Health
Library npm

json-2-csv

Converts arrays of JSON documents to RFC 4180 compliant CSV and back, with native support for nested sub-documents.

458
MIT
Used by 8
57Health
Library Cargo

humantime

A fast parser and formatter for std::time::Duration and SystemTime in human-friendly notation

396
Apache 2.0
Used by 8
87Health
Framework npm

oclif Core

The Node.js framework that powers Salesforce CLI and Heroku CLI, providing flag parsing, help generation, and a plugin system for building CLIs.

317
MIT
Used by 8
93Health
Library PyPI

Faker

A Python library that generates realistic fake data for testing, seeding, and anonymizing datasets across 70+ locales.

19,412
MIT
Used by 7
42Health
Library Cargo

nom

A byte-oriented, zero-copy parser combinators library for Rust

10,475
MIT
Used by 7
79Health
Tool PyPI

Sphinx

A documentation generator that turns reStructuredText or Markdown sources into polished HTML, PDF, EPUB, and more.

8,035
Other
Used by 7
83Health
SDK PyPI

PyGithub

A typed Python library for the GitHub REST API, wrapping repositories, issues, pull requests, and organizations as lazy-loading objects.

7,779
Other
Used by 7
53Health
Library npm

diff2html

Generate pretty, GitHub-style HTML diffs from git diff or unified diff output

3,415
MIT
Used by 7
67Health
Library PyPI

ddgs

A Python metasearch library that aggregates text, image, news, and video search results

2,992
MIT
Used by 7
53Health
Library PyPI

django-storages

Pluggable cloud and remote storage backends for Django's file storage API

2,959
BSD 3
Used by 7

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