GE Great Expectations project (open-source stewardship by Fivetran) · Data quality & validation
Python data-quality framework that declares Expectations about datasets, validates them against pandas, Spark or SQL sources and produces Data Docs
Apache-2.0 Open source Free Local Self-hosted Nov 2, 2026I Jason Liu and contributors (567 Labs) · Agent frameworks & orchestration
Python library for extracting validated structured data from LLM responses using Pydantic models, with automatic retries, streaming partials and support for many providers
MIT Open source Free Local Nov 2, 2026K Kùzu Inc. (company acquired; project archived) · NoSQL & key-value stores
In-depth entry Embedded property-graph database with Cypher, vector and full-text search; MIT-licensed but archived in October 2025 after the company was acquired
MIT Open source Free Local Discontinued Nov 2, 2026M marimo (acquisition by CoreWeave announced October 2025) · Notebooks & interactive computing
Reactive Python notebook stored as a plain .py file that re-runs dependent cells automatically and doubles as a script or web app
Apache-2.0 Open source Free Local Self-hosted Nov 2, 2026M Matplotlib Development Team (NumFOCUS) · Data visualization
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 Open source Free Local Nov 2, 2026M Meili SAS · Vector databases
Rust search engine for application search-as-you-type with typo tolerance, faceting and hybrid semantic search; MIT core plus BSL enterprise parts
MIT AND BUSL-1.1 Open source Free Self-hosted Nov 2, 2026M Metabase, Inc. · BI & dashboards
Self-hostable BI tool with a no-code question builder, SQL editor, dashboards and embedding; AGPL open-source edition plus commercial Pro and Enterprise
AGPL-3.0 Open source Free Self-hosted Nov 2, 2026M Zilliz / LF AI & Data Foundation · Vector databases
Open-source vector database from Zilliz with Lite, Standalone and Distributed deployments, many index types and GPU acceleration
Apache-2.0 Open source Free Local Self-hosted Nov 2, 2026M Oracle · Relational databases
Oracle's widely deployed open-source relational database server, offered as a GPL community edition and commercial enterprise and cloud editions
GPL-2.0-only WITH Universal-FOSS-exception-1.0 Open source Free Self-hosted BrokenN NATS project (CNCF; maintained principally by Synadia) · Messaging & queues
Lightweight Go messaging system with core pub/sub and request-reply plus JetStream persistence, key-value and object stores; a CNCF project
Apache-2.0 Open source Free Self-hosted Nov 2, 2026N Neo4j, Inc. · NoSQL & key-value stores
Native property-graph database queried with Cypher, offered as a GPL community edition, a commercial enterprise edition and the AuraDB cloud service
GPL-3.0 Open source Freemium Self-hosted BrokenN NumPy developers (NumFOCUS) · DataFrames & array computing
Foundational Python library for n-dimensional arrays, vectorized math, linear algebra, random numbers and the array API used by the scientific stack
BSD-3-Clause Open source Free Local BrokenO Observable, Inc. · Notebooks & interactive computing
JavaScript data notebooks and the open-source Observable Framework static-site generator for data apps, from the maintainers of D3 and Plot
ISC Freemium Paid Local Nov 2, 2026O OpenSearch Software Foundation (Linux Foundation) · Vector databases
Apache-2.0 search and analytics suite forked from Elasticsearch and Kibana, governed by the OpenSearch Software Foundation
Apache-2.0 Open source Free Self-hosted BrokenP pandas development team (NumFOCUS) · DataFrames & array computing
In-depth entry The standard Python DataFrame library for labeled tabular data, time series and I/O to CSV, Excel, SQL, Parquet and more
BSD-3-Clause Open source Free Local Nov 2, 2026P Union.ai (Pandera project, created by Niels Bantilan) · Data quality & validation
Lightweight Python library for declaring and validating DataFrame schemas for pandas, Polars, PySpark and other backends, with type-hint style models
MIT Open source Free Local Nov 2, 2026P Tim Jones (pg-boss project) · Messaging & queues
Node.js job queue that uses PostgreSQL tables and SKIP LOCKED for reliable background jobs, scheduling and retries without a separate broker
MIT Open source Free Local Self-hosted Nov 2, 2026P Andrew Kane (pgvector project) · Vector databases
In-depth entry PostgreSQL extension adding vector types, distance operators and HNSW/IVFFlat indexes for similarity search inside the database
PostgreSQL Open source Free Self-hosted Nov 2, 2026Microsoft's browser automation and end-to-end testing framework driving Chromium, Firefox and WebKit from one API in TypeScript, Python, Java and .NET
Apache-2.0 Open source Free Local Self-hosted Nov 2, 2026P Plotly Technologies Inc. · Data visualization
MIT-licensed interactive charting libraries for Python (plotly.py), JavaScript (plotly.js) and R, plus the Dash framework for analytical web apps
MIT Open source Free Local Nov 2, 2026P Polars (Ritchie Vink and contributors) · DataFrames & array computing
In-depth entry Rust-based DataFrame library with Python, Rust, Node and R bindings offering lazy query optimization, multithreading and Arrow-native memory
MIT Open source Free Local Nov 2, 2026P PostGIS Project Steering Committee (OSGeo) · GIS & mapping
In-depth entry Spatial extension for PostgreSQL adding geometry, geography and raster types with indexing and hundreds of SQL functions
GPL-2.0-or-later Open source Free Self-hosted Nov 2, 2026P PostgreSQL Global Development Group · Relational databases
In-depth entry Open-source object-relational database server with a large extension ecosystem (PostGIS, pgvector, TimescaleDB) and broad SQL coverage
PostgreSQL Open source Free Local Self-hosted BrokenP Prefect Technologies, Inc. · ETL/ELT & orchestration
Python workflow orchestration library and server where decorated functions become observable, retryable flows, with Prefect Cloud as hosted option
Apache-2.0 Open source Freemium Local Self-hosted Redirected