Directory

Document database storing BSON documents with a rich aggregation pipeline, available as a source-available Community Server or the managed Atlas service

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

Native property-graph database queried with Cypher, offered as a GPL community edition, a commercial enterprise edition and the AuraDB cloud service

Foundational Python library for n-dimensional arrays, vectorized math, linear algebra, random numbers and the array API used by the scientific stack

The standard Python DataFrame library for labeled tabular data, time series and I/O to CSV, Excel, SQL, Parquet and more

Lightweight Python library for declaring and validating DataFrame schemas for pandas, Polars, PySpark and other backends, with type-hint style models

Node.js job queue that uses PostgreSQL tables and SKIP LOCKED for reliable background jobs, scheduling and retries without a separate broker

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

MIT-licensed interactive charting libraries for Python (plotly.py), JavaScript (plotly.js) and R, plus the Dash framework for analytical web apps

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

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

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

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

Python data-validation library using type hints to parse, validate and serialize models, with a Rust core; the schema layer behind FastAPI and many LLM SDKs

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

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

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