Open source. Open possibilities.

Apache Cassandra is a highly-scalable, transactional distributed partitioned row store designed for fault-tolerance on commodity hardware or cloud infrastructure.

pgfathom is a read‑only CLI tool that discovers undocumented PostgreSQL relationships by analyzing catalog data, usage evidence, and statistics. It outputs verdicts (broken, confirmed, weak) and reviewable SQL scripts to help fix hidden foreign keys.

A lightning-fast search engine API providing AI-powered hybrid search, typo tolerance, and search-as-you-type capabilities for websites and applications.

DSH engineer-level database plugin offering six tools—sql_list/query/exec/schema/stats/health—supporting SQLite, MySQL, and PostgreSQL with multiple connections, featuring read-only whitelisting, write approval gates, lexical read-only protection, streaming row clamping, and configurable timeouts.

TimescaleDB is a PostgreSQL extension designed for high-performance real-time analytics on time-series and event data.

ChaosSQL is a deterministic concurrency and isolation fuzzer for PostgreSQL, MySQL and SQLite. It schedules concurrent transactions, detects invariant violations such as lost updates and write skew, shrinks failures to minimal reproductions, and can guard CI pipelines against regressions.

pgrust is a Rust re-implementation of PostgreSQL designed for high performance, featuring wire and SQL dialect compatibility with Postgres.

Metabase is an open-source business intelligence and embedded analytics tool designed to allow users to query data and create dashboards without requiring SQL knowledge.

OwnChat is a self-hosted desktop chat application built with Java Swing and sockets, using Oracle Database for storage. It supports account creation, contacts, real-time messaging, chat history, themes, and online status tracking.

etcd is a distributed, reliable key-value store written in Go that uses the Raft consensus algorithm for highly available replicated logs. It offers a simple gRPC API, TLS security, and is widely used in production for critical distributed system data, notably with Kubernetes.

DBeaver is a free, multi-platform database tool and SQL client for developers, DBAs and analysts, supporting 100+ database drivers via JDBC/ODBC, with SQL editor, data editor, ER diagrams, import/export and AI chat integration.

Supabase is an open-source Postgres development platform combining hosted database, authentication, auto-generated REST/GraphQL and realtime APIs, edge functions, file storage, an AI/vector toolkit, and a dashboard, with official and community client libraries.

ChartDB is an open-source, web-based database diagram editor that lets you visualize schemas instantly with a single query. No installation or password needed. Supports multiple databases and AI-powered SQL export.

Directus wraps any SQL database with auto-generated REST and GraphQL APIs, a visual management Studio, and a native MCP server for AI agents. It supports granular permissions and self-hosting.

Flow is a single-binary, high-performance ETL engine and workflow orchestrator written in Go. It features an embedded visual web builder, declarative XML pipelines, cross-database support, and built-in audit telemetry.

Nhost is an open-source Firebase alternative offering GraphQL, PostgreSQL, auth, storage, and serverless functions. Supports local dev, self-hosting, and multiple frontends.

AllSource is an AI-native event store built in Rust, featuring high-throughput ingestion, low-latency reads, and native MCP integration for AI agents. It supports durable event sourcing without Postgres, includes an agent memory engine, and offers community and enterprise editions.

RocksDB is an embeddable, persistent key-value store library from Facebook's Database Engineering Team, designed for fast storage on flash and RAM. It uses an LSM design with multi-threaded compactions and supports terabyte-scale databases.

bytdb is an embedded, pure Go SQL database that is Postgres-compatible, offering a single-file relational store with no external server or cgo dependencies.

Kahuna is an open-source distributed systems toolkit providing distributed locking, a fault-tolerant key/value store, and globally ordered ID sequencing, built on Raft consensus and MVCC.