Directory

Python testing framework with plain assert statements, fixtures, parametrization and a large plugin ecosystem, the de facto standard for Python test suites

General-purpose, dynamically typed programming language with a large standard library and the dominant ecosystem for data science and machine learning

Open-source deep-learning framework with eager tensors, autograd, torch.compile and distributed training, governed by the PyTorch Foundation and the base of most LLM tooling

Algorithmic trading platform built on the open-source LEAN engine, with cloud backtesting, research notebooks and brokerage-connected live trading

Open-source message broker in Erlang supporting AMQP 0-9-1 and 1.0, MQTT, STOMP and Streams, with routing, acknowledgements and quorum queues

Open-source Python framework for distributing tasks, actors and ML workloads across a cluster, with libraries for data processing, training, tuning, serving and reinforcement learning

Component-based JavaScript library for building user interfaces, created at Meta, with hooks, a declarative rendering model and server components

In-memory key-value data store used as cache, message broker and database, with data structures, Pub/Sub, Streams and, since Redis 8, built-in JSON, search and time-series modules

Mature open-source Python framework for writing crawlers (spiders) that fetch pages asynchronously, extract structured items and export them through pipelines

Python documentation generator using reStructuredText or MyST Markdown with cross-referencing, API autodoc and output to HTML, PDF via LaTeX, ePub and man pages

Utility-first CSS framework from Tailwind Labs that styles markup with composable class names and generates only the CSS a project uses

PostgreSQL extension for time-series data adding hypertables, compression and continuous aggregates, from the company now named Tiger Data

Distributed SQL query engine that federates queries across data lakes, warehouses and databases through connectors, formerly PrestoSQL

Statically typed superset of JavaScript from Microsoft that compiles to plain JavaScript and powers editor tooling across the web ecosystem

Markup-based typesetting system with an Apache-2.0 compiler written in Rust and a collaborative web app, positioned as a faster, simpler alternative to LaTeX

Front-end build tool and development server that serves native ES modules during development and bundles for production, with a plugin API shared by many frameworks

Vite-native unit test framework for JavaScript and TypeScript with a Jest-compatible API, watch mode, coverage and browser mode