Directory

Language-independent columnar in-memory format and libraries that let DuckDB, Polars, pandas, Spark and databases exchange tables without copying

Distributed event streaming platform with durable, partitioned, replayable logs, Kafka Connect connectors and Kafka Streams processing

Open columnar file format for analytical data with compression, encodings and statistics, readable by nearly every data engine and library

Open-source columnar OLAP database server for fast aggregations over billions of rows, with MergeTree storage, SQL and a managed ClickHouse Cloud

In-process analytical SQL database that queries Parquet, CSV and Arrow data directly from Python, R, Node or the CLI

Python library extending pandas with geometry columns, spatial operations, reprojection, spatial joins and file I/O for vector geodata

Embedded property-graph database with Cypher, vector and full-text search; MIT-licensed but archived in October 2025 after the company was acquired

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

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

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

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