Directory

Python workflow orchestration library and server where decorated functions become observable, retryable flows, with Prefect Cloud as hosted option

Opinionated code formatter for JavaScript, TypeScript, CSS, HTML, Markdown, YAML and more that reprints code from its syntax tree with few options

TypeScript ORM with a declarative schema language, generated type-safe client and migration tooling, from the company that also offers Prisma Postgres and related hosted services

Open-source computational notebook ecosystem: the .ipynb format, kernels for Python, R and Julia, JupyterLab and Notebook interfaces and JupyterHub

Open-source, local-first CLI and library for evaluating prompts, models, RAG pipelines and agents, with automated red teaming and CI integration

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

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

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

Static analysis engine that matches code patterns written in the target language's own syntax, with an LGPL community edition and a commercial AppSec platform

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

Open-source backend platform built around a dedicated PostgreSQL database with auto-generated APIs, authentication, file storage, realtime subscriptions and edge functions

WireGuard-based mesh overlay network with a hosted coordination service, identity-provider login, access policies, MagicDNS and features such as Tailscale SSH, Serve and Funnel

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

Web search, extraction, crawling and research API designed for LLM agents, returning concise source content with SDKs, framework integrations and a hosted MCP server

Infrastructure-as-code tool that provisions cloud and SaaS resources from HCL configurations through a plan-and-apply workflow, licensed under BSL 1.1

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

Build system for JavaScript and TypeScript monorepos from Vercel that runs package tasks in dependency order with local and remote caching

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 cloud from the makers of Next.js that deploys web applications from git with preview environments, serverless and edge functions and a global CDN