Directory

Microsoft's browser automation and end-to-end testing framework driving Chromium, Firefox and WebKit from one API in TypeScript, Python, Java and .NET

Rust-based DataFrame library with Python, Rust, Node and R bindings offering lazy query optimization, multithreading and Arrow-native memory

Spatial extension for PostgreSQL adding geometry, geography and raster types with indexing and hundreds of SQL functions

Open-source object-relational database server with a large extension ecosystem (PostGIS, pgvector, TimescaleDB) and broad SQL coverage

Commercial API platform for designing, testing, documenting and monitoring HTTP and other APIs through a desktop and web client with cloud-synced workspaces

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

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

Open-source vector search engine written in Rust with filterable HNSW indexes, sparse and multi-vector support, REST/gRPC APIs and a managed cloud

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

Channel-based team messaging platform from Salesforce with threads, huddles, canvases, workflow automation and an extensive bot and app API

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

Salesforce's visual analytics platform: Tableau Desktop authoring (now with a free edition), Tableau Cloud and Server for sharing, and Tableau Next for CRM analytics