Directory

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

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

Node.js library from the Chrome team for controlling Chrome and Firefox over the DevTools Protocol or WebDriver BiDi, used for scraping, screenshots, PDFs and testing

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

Open-source desktop GIS for viewing, editing, analysing and publishing vector and raster geodata, extensible with Python plugins

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

Open-source C++ library for quantitative finance covering instruments, term structures, pricing engines and calendars, with Python and other bindings

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

Public-domain embedded SQL database engine that stores a whole database in one file and ships inside most operating systems and browsers

Python library for estimating statistical and econometric models with R-style formulas, rich result summaries and tests: OLS, GLM, discrete choice, ARIMA, state space, VAR and more

Apple's compiled, memory-safe, multi-paradigm language for Apple platforms, Linux, Windows and embedded targets, developed in the open at swift.org

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

High-throughput LLM inference and serving engine with PagedAttention, continuous batching, quantization and an OpenAI-compatible server for GPU and accelerator clusters