Directory

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

Extensible Rust query engine built on Apache Arrow offering SQL and DataFrame APIs, Parquet readers and an optimizer for embedding in data systems

Distributed data processing engine with DataFrame and SQL APIs in Python, Scala, Java and R, plus structured streaming and MLlib

Self-hosted, open-source web archiving tool that saves URLs as HTML, PDF, screenshot, WARC, readable text and media snapshots with a web UI and CLI

Redis-backed job and message queue for Node.js (with a Python port) offering workers, flows, rate limiting, repeatable jobs and a commercial Pro tier

Open-source embedding database with a minimal Python and JavaScript API, usable in-process, as a server or through Chroma Cloud

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

Open-source crawling and scraping library for Node.js/TypeScript and Python that unifies HTTP and headless-browser crawlers with queues, proxies, fingerprints and storage

Asset-oriented Python orchestrator that models pipelines as software-defined data assets with lineage, checks and a hosted Dagster+ option

Python library for parallel and distributed computing that scales pandas, NumPy and custom task graphs from a laptop to a cluster

SQL-first transformation framework that compiles templated models, tests and documentation into warehouse tables; open-source Core plus a commercial platform

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

Python data-quality framework that declares Expectations about datasets, validates them against pandas, Spark or SQL sources and produces Data Docs

Python library for extracting validated structured data from LLM responses using Pydantic models, with automatic retries, streaming partials and support for many providers

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

Reactive Python notebook stored as a plain .py file that re-runs dependent cells automatically and doubles as a script or web app

The foundational Python plotting library for static, publication-quality figures with full control over every element, exported to PDF, SVG, PNG and PGF

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

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

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

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