Document databases

The default document database: flexible BSON documents, rich queries and built-in sharding.

Google's app platform: Firestore, Realtime Database and Data Connect, plus auth, functions and hosting.

Serverless document database with realtime listeners, offline SDKs and a new Enterprise edition.

Microsoft's globally distributed, multi-API NoSQL and vector database with SLA-backed latency.

HTTP/JSON document database built around multi-master replication and offline-first sync.

Open-source JSON database that pushes live query results to apps through changefeeds.

IBM's managed, CouchDB-compatible JSON database with built-in search and geospatial queries.

ACID document database for .NET and beyond, with auto-indexing, Corax search and multi-master replication.

Rust multi-model database (documents, graph, vectors, live queries) that runs embedded, in WASM or clustered.

Memory-first distributed JSON database with SQL++, search, vector indexes and mobile sync.

Firebase's original JSON-tree database that syncs every change to connected clients in milliseconds.

Reactive TypeScript backend with a transactional document database, server functions and live queries.

Apple's iCloud record store for apps: private per-user data, a public database and built-in sync.

The most popular IndexedDB wrapper, with live queries and an optional Dexie Cloud sync service.

JavaScript database for browsers and Node that speaks the CouchDB replication protocol.

Enterprise multi-model database for XML, JSON and RDF with built-in search and semantic RAG.

Pure-Python document store that keeps every table in one human-readable JSON file.

Reactive local-first NoSQL database for JavaScript with pluggable storage and replication.

In-memory JavaScript document store with indexes and pluggable persistence; no longer maintained.

Full-stack syncing database for TypeScript apps; development has stalled since 2025.

Tiny type-safe local JSON database for Node, Electron and the browser using plain JavaScript.

AWS's managed MongoDB-API database on a proprietary, Aurora-style storage layer.

MongoDB's own multi-cloud DBaaS, bundling search, vector search and stream processing.

Tiny in-memory JavaScript collection library with SQL-like filtering for the browser and Node.js.

Local-first database with built-in sync, permissions and edit history, being rebuilt as a relational Jazz 2.

Serverless single-file NoSQL document database for .NET, in the spirit of SQLite.

Serverless peer-to-peer database on IPFS and libp2p using Merkle-CRDT logs.

Apache-licensed MongoDB-protocol proxy that stores data in PostgreSQL with the DocumentDB extension.

Node.js runtime that fuses database, cache, app logic and MQTT/WebSocket messaging in one process.

Embedded JSON document database with SQL++ queries, vector search and sync to Couchbase.

Embeddable bitemporal database that keeps every revision of JSON and XML resources queryable.

Drop-in MongoDB Community build with enterprise features like encryption, LDAP and hot backup.

MIT-licensed, MongoDB-compatible document engine built as PostgreSQL extensions, run by the Linux Foundation.

Embeddable JSON document database in C, with a JQL query language and optional HTTP/WebSocket server.

Edge-native document database that syncs peer-to-peer over Bluetooth, P2P Wi-Fi and LAN without internet.

Embedded BSON document database for Rust with a MongoDB-like API and optional wire-protocol server.

Chinese distributed document database with native ACID storage, SQL instances and S3 API, used in many banks.

Embedded NoSQL document store for Java and Android with pluggable MVStore or RocksDB storage.

Dependency-free PHP library that stores schemaless documents as plain JSON files on disk.

Structured static database for game data: spreadsheet-style editor, typed sheets and diff-friendly JSON.

Converged C/C++ NoSQL platform mixing key-value, documents, time-series, stream processing, graph and ML.

Apache parallel database for semi-structured JSON data with SQL++, LSM storage and spatial/text indexes.

PHP library that treats JSON files as database tables, with an ORM-style query builder and relations.

Ruby transactional document store that keeps every change as a commit in a Git repository.

Self-tuning document-graph database with automatic indexing, full version history and time-travel reads.

Lightweight Java document database usable embedded (including Android) or as a REST server.

Microsoft's managed MongoDB-compatible service, built on the open-source DocumentDB engine.

Couchbase's managed DBaaS: Couchbase Server clusters plus App Services sync and AI tooling.

Embedded transactional table-style document database for Java and .NET, including Android and Unity.

The extensible, standards-first open-source relational database.

The in-memory data structure server that became the default cache, now with search, JSON and vectors built in.

The web's default open-source SQL database, now on calendar versioning with 9.7 as the LTS line.

The in-process SQL engine that ships in every phone, browser and OS: one file, zero servers.

Lucene-based distributed search and analytics engine for text, vectors, logs and metrics.

Fully managed cloud data warehouse with separate storage and compute, now spanning AI and apps.

Microsoft's flagship RDBMS: T-SQL, columnstore, Always On, and now native vectors and JSON.

Open-source columnar OLAP database known for very fast aggregations over billions of rows.

Google's serverless, pay-per-query data warehouse built on Dremel and Colossus.

In-process columnar SQL database: the SQLite of analytics, running inside your app or notebook.

AWS's serverless key-value and document store with single-digit-millisecond reads at any scale.

The enterprise heavyweight: RAC, Data Guard and a converged engine for SQL, JSON, graph and vectors.

Apache-licensed, foundation-governed fork of Elasticsearch for search, vectors and observability.

Community-led MySQL fork with extra storage engines, built-in Galera and a faster feature cadence.

AWS's MPP columnar data warehouse, available as provisioned RA3 clusters or Serverless.

Hosted search-as-a-service with fast typo-tolerant search, merchandising and AI ranking.

Open-source Postgres backend platform: database, auth, storage, realtime and edge functions in one project.

Spark's SQL and DataFrame engine for large-scale batch, streaming and lakehouse processing.

Open-source retrieval database for AI apps, from embedded Python to serverless Chroma Cloud.

Postgres-wire distributed SQL built to survive node, zone and region failures with serializable transactions.

Cloud-native, distributed open-source vector database built for billions of vectors.

IBM's enterprise RDBMS for Linux, UNIX, Windows and z/OS, with BLU columnar and pureScale clustering.

Flash-optimized distributed key-value and document database for predictable sub-millisecond latency at scale.

Native multi-model database: documents, graphs, search and vectors behind one query language.

The original Lucene search server: battle-tested, Apache-governed, now with GPU-accelerated vectors.

SAP's in-memory columnar HTAP database, the mandatory engine under S/4HANA.

Serverless cloud data warehouse built on DuckDB, with hybrid local-plus-cloud execution.

Rust vector search engine with rich payload filtering, quantization and a managed cloud.

MySQL-compatible distributed SQL with a row store for OLTP and a columnar replica for real-time analytics.

Real PostgreSQL compiled to WebAssembly: an embeddable Postgres for browsers, Node, Bun and Deno.

Microsoft's always-current managed SQL Server engine, from free serverless databases to 128 TB Hyperscale.

A Java in-memory data grid and stream processor that embeds in your app or runs as a cluster.

Open-source AI-native vector database with hybrid search, modules for embeddings and multi-tenancy.

Veteran MPP columnar analytics database from the C-Store lineage, now owned by Rocket Software.

Apache-licensed distributed SQL that reuses the PostgreSQL query layer on a Raft-replicated storage engine.

Microsoft's managed search service for full-text, vector, hybrid and agentic retrieval on Azure.

Developer-friendly Rust search engine with typo tolerance and built-in hybrid semantic search.

Open-source backend in one Go binary: SQLite database, auth, files, realtime and admin UI.

The browser's built-in transactional object store, and the storage layer under most web local-first libraries.

Microsoft's Kusto engine: fast KQL analytics over logs, telemetry and time series at petabyte scale.

Serverless Postgres with copy-on-write branching and scale-to-zero, now part of Databricks.

Turso's open-contribution SQLite fork with native vectors, a network server and embedded replicas.

Distributed SQL mixing in-memory rowstore and columnstore for real-time analytics, search and vectors.

Red Hat's open-source distributed cache and key-value store, embeddable or as a RESP-compatible server.

In-memory, typo-tolerant search engine in C++ with vector, hybrid and conversational search.

Early Java multi-model database mixing documents, graphs and objects, now in patch-only mode.

Open-source distributed SQL from Yandex combining row and column tables, topics and vector search.

Distributed SQL database built on Lucene for real-time analytics over machine, IoT and JSON data.

Open-source backend platform with databases, auth, storage, functions and realtime, self-hosted or cloud.

AWS's managed service for six relational engines: PostgreSQL, MySQL, MariaDB, Oracle, SQL Server and Db2.

Serverless vector and full-text search on object storage, priced for billions of documents.

Low-maintenance embeddable RDBMS with built-in TimeSeries, still quietly running retail and telco systems.

Performance-focused managed MySQL (Vitess) and Postgres, with NVMe-backed Metal clusters and branching.

AWS's MySQL- and PostgreSQL-compatible engine on a shared, six-way replicated storage layer.

Big-data serving engine for search, recommendation and RAG with tensors and ML ranking.

A drop-in MySQL build that ships enterprise features (thread pool, audit, encryption) as free GPL code.

In-memory database and Lua application server in one process, with an optional disk engine.

CNCF-graduated sharding and clustering layer that makes a fleet of MySQL servers look like one database.

Embedded, in-process OLAP engine powered by ClickHouse, used mainly from Python.

Postgres extension that shards tables across nodes for multi-tenant SaaS and real-time analytics.

Git-for-data document and knowledge-graph database with branches, diffs and time travel.

Serverless SQL warehouses on the Databricks lakehouse, powered by the Photon C++ engine.

A multi-threaded, shared-nothing in-memory store that speaks Redis and Memcached on one big box.

PostgreSQL-based MPP data warehouse, closed-sourced by Broadcom in 2024 and sold in Tanzu Data.

In-memory, partitioned SQL engine running Java stored procedures serially for millisecond decisioning.

Pure-JavaScript in-memory SQL engine for browsers and Node.js that queries arrays, JSON, CSV and Excel files.

Tiny TypeScript full-text, vector and hybrid search engine for browsers, servers and the edge.

Alipay-proven distributed SQL with MySQL (and Oracle, in Enterprise) compatibility, HTAP and vector search.

Open-source native XML database and XQuery application platform for documents and digital editions.

Fast SQL-first search database, forked from Sphinx, with columnar storage and vector KNN.

MySQL-compatible SQL database you can branch, diff, merge and clone like a Git repository.

Lightweight, fast native XML database and XQuery 3.1/4.0 processor with a GUI.

Immutable, tamper-evident database with cryptographic proofs, offering key-value, SQL and document APIs.

Lisp-built RDF and document knowledge graph with vector store, reasoning and LLM agents.

Real-time MPP analytical database with MySQL compatibility, search indexes and lakehouse access.

Oracle's long-running Java data grid, with a UPL-licensed Community Edition on GitHub.

AWS's original 2007 schemaless attribute store; still running but frozen in time.

MPP OLAP database with a fast vectorized engine, real-time upserts and native lakehouse queries.

Rust-built cloud data warehouse on object storage, open source with a managed Databend Cloud.

Oracle's engineered system for Oracle Database, with smart storage offload for OLTP and analytics.

Serverless Postgres from the Prisma ORM team, on unikernels, billed per operation with no cold starts.

End-to-end tensor search engine that embeds text and images for you, built on Vespa.

Multi-model Java database speaking SQL, Cypher, Gremlin, MongoDB and Redis protocols.

Oracle's sharded key-value and JSON store, available as Apache-licensed software or an OCI service.

Apache's Java Content Repository: a hierarchical, versioned node store with search, behind many Java CMSs.

Multi-model data platform (SQL, objects, globals, vectors) with built-in interoperability, big in healthcare.

EnterpriseDB's PostgreSQL with deep Oracle compatibility: PL/SQL packages, DBMS_* and TDE.

Version-controlled SQL database with PostgreSQL compatibility: branch, diff and merge your tables.

Vercel's globally replicated read-optimized config store (renamed Global Config in 2026).

Cloud-native search engine on object storage for logs and traces, built on Tantivy.

Serverless Cassandra-as-a-service with vector search and a JSON Data API, now owned by IBM.

Blockchain-style database combining MongoDB storage with Tendermint BFT consensus; dormant since 2020.

Faceted-search and discovery engine (MDEX) that Oracle bought in 2011; now a frozen Oracle Commerce component.

Google Cloud's managed MySQL, PostgreSQL and SQL Server, with an Enterprise Plus tier for fast failover.

Managed SQLite-compatible cloud for database-per-tenant apps, with embedded replicas and offline sync.

A Redis-protocol database on RocksDB that trades a little latency for disk-sized capacity.

Percona Server plus Galera synchronous replication, packaged as an open-source HA MySQL cluster.

Fully open-source multi-master distributed PostgreSQL built on the Spock logical replication extension.

Serverless Postgres that makes tenants a first-class primitive, with per-tenant isolation and placement.

Enterprise RAG and agent platform with managed hybrid retrieval, reranking and hallucination scoring.

Bitemporal SQL database on object storage that keeps every version of every row.

Low-latency analytical database with a Postgres-compliant dialect, as cloud service or self-hosted Core.

A native .NET distributed cache and data grid for Windows and Linux, with an Apache-licensed edition.

Open-source Postgres platform with storage-level copy-on-write branching, scale-to-zero and anonymized clones.

Open-source MPP warehouse forked from Greenplum and rebased on a newer PostgreSQL kernel.

China's leading home-grown RDBMS; DM9 (2026) adds distributed, HTAP and AI features.

Huawei-originated open-source RDBMS forked from PostgreSQL, with in-memory and column engines.

Serverless SQLite for Cloudflare Workers, priced per row read and written, with read replicas and time travel.

Apache-licensed PostgreSQL distribution with an Oracle-compatible mode, PL/iSQL and Oracle packages.

Lightweight single-binary full-text search engine in Go with Elasticsearch-compatible ingest.

Alibaba's open-source, MySQL-compatible shared-nothing distributed SQL with Paxos and columnar indexes.

Microsoft's managed community PostgreSQL, with zone-redundant HA, DiskANN vectors and Citus elastic clusters.

GigaSpaces' Java in-memory data grid with space-based processing, SQL queries and tiered storage.

The relational database built into IBM i (AS/400), integrated with the OS and object security.

Embedded, transactional key-value and JSON document engine in a single C file, with Jx9 scripting.

PostgreSQL-compatible MPP warehouse that runs on its appliance, any cloud or Kubernetes.

Fast Flutter/Dart object database with rich indexed queries, now stalled upstream.

Google's Postgres-compatible service with disaggregated storage, a columnar engine and ScaNN vectors.

AWS's original managed search service, closed to new customers since July 2024.

Boiler Bay's all-Java embedded B-tree database with a ConcurrentNavigableMap API and a server edition.

Chinese Java OLTP database derived from H2, now repositioned as an AI agent platform built on its SQL engine.

Alibaba Cloud's shared-storage relational service in MySQL-, PostgreSQL- and Oracle-compatible editions.

Commercial cloud and enterprise distribution of Apache Doris from its core maintainers.

Redis Ltd.'s own managed Redis on AWS, Azure and GCP, with Active-Active geo-replication and tiering.

Tiny embeddable C string key-value database from the radare2 project, built on djb's cdb format.

Schema-less multi-model engine from Germany's Cortex AG, now sold as CortexEngine within Cortex-IP.

Managed horizontal sharding for Aurora PostgreSQL: one endpoint over a serverless group of shards.

Databricks' serverless Postgres built on Neon tech, with branching and sync to Delta tables in Unity Catalog.

Small Java key/value API for JSON objects over LevelDB, RocksDB, LMDB or MySQL; abandoned in 2014.

Oracle's managed MySQL with an in-memory columnar engine for analytics, lakehouse, ML and vector search.

Microsoft's managed Redis built on Redis Enterprise, replacing the retiring Azure Cache for Redis.

Crunchy Data's developer-friendly managed Postgres across AWS, GCP and Azure, now owned by Snowflake.

FairCom's embeddable ISAM, SQL and JSON database engine, now sold as FairCom DB; roots in 1984's c-tree.

IBM's MPP analytics edition of Db2 with BLU columnar acceleration, as software or SaaS.

Chinese PostgreSQL-derived RDBMS with Oracle, MySQL and SQL Server compatibility modes.

Self-driving Oracle Database on Exadata: auto-patching, auto-scaling, and Select AI, on OCI and other clouds.

Russian commercial PostgreSQL distribution with multimaster, 64-bit XIDs and compressed storage.

Commercial in-memory data grid for .NET and Java with parallel query, Redis support and in-cache code.

Packaged enterprise search and RAG platform built on OpenSearch, with crawlers, connectors and hybrid search.

Tencent's financial-grade MySQL-compatible database family: distributed TDSQL and cloud-native TDSQL-C.