Directory

Open-source vector database from Zilliz with Lite, Standalone and Distributed deployments, many index types and GPU acceleration

Python static site generator for project documentation that builds a navigable site from Markdown files and a single YAML configuration

Open JSON-RPC standard for connecting AI applications to tools, data and prompts through servers, now stewarded under the Linux Foundation with SDKs in many languages

Open-source learning management system used by universities and schools for courses, assignments, quizzes, grading and forums, self-hosted or via MoodleCloud

Oracle's widely deployed open-source relational database server, offered as a GPL community edition and commercial enterprise and cloud editions

Lightweight Go messaging system with core pub/sub and request-reply plus JetStream persistence, key-value and object stores; a CNCF project

Serverless PostgreSQL service with separated storage and compute, instant database branching and scale-to-zero, now part of Databricks

React framework from Vercel for full-stack web applications with file-based routing, server components, server-side rendering, static generation and API route handlers

Server-side JavaScript runtime built on the V8 engine, governed by the OpenJS Foundation, with npm as its package ecosystem

JavaScript data notebooks and the open-source Observable Framework static-site generator for data apps, from the maintainers of D3 and Plot

Modular open-source business suite (CRM, invoicing, accounting, inventory, website, HR) with an LGPL community edition and a hosted or licensed enterprise edition

Open-source runtime and model manager for running open-weight LLMs locally on macOS, Windows and Linux, with a REST API, OpenAI- and Anthropic-compatible endpoints and optional cloud models

Lightweight open-source Python and TypeScript framework for agents, handoffs, guardrails, sessions and tracing, defaulting to OpenAI's Responses API with adapters for other providers

OpenAI's coding agent: an open-source Rust terminal CLI plus IDE extension, desktop app and cloud agent, signed in with a ChatGPT plan or an API key

Vendor-neutral, machine-readable standard for describing HTTP APIs in JSON or YAML, maintained by the OpenAPI Initiative under the Linux Foundation

Apache-2.0 search and analytics suite forked from Elasticsearch and Kibana, governed by the OpenSearch Software Foundation

Free, open-source research management platform from the Center for Open Science for projects, preregistrations, registries, preprint services and linking outputs across storage providers

Collaborative online LaTeX editor with real-time co-editing, templates and reference-manager sync, available as a hosted service and an AGPL self-hosted edition

Read-only query service for OpenStreetMap data using the Overpass QL language, available on public instances or self-hosted

PostgreSQL extension adding vector types, distance operators and HNSW/IVFFlat indexes for similarity search inside the database

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