Databases for Caching

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

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

The Linux Foundation's BSD-licensed fork of Redis, now the default engine on AWS and Google Cloud.

The original multi-threaded, dead-simple distributed memory cache for key-value blobs.

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

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

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

AWS's managed Valkey, Redis OSS and Memcached service, provisioned or serverless.

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

A distributed, memory-first SQL database and compute grid; Ignite 3 rebuilt it around Raft and Calcite.

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

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

Serverless, per-request-priced Redis with an HTTP API built for edge and serverless functions.

Tiny reactive in-memory store for tables and values, with persisters and CRDT sync.

The standard embedded JVM cache, with heap, off-heap and disk tiers and optional Terracotta clustering.

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

Snap's multi-threaded Redis fork with active-active replication and FLASH storage, now dormant.

The open-source core of GemFire: a consistent, partitioned in-memory data grid for Java.

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

Lightweight pure-Dart key-value store for Flutter; development continues in the Hive CE fork.

Managed Valkey and serverless cache/pub-sub from ex-DynamoDB engineers, plus self-hosted Valkey tooling.

Off-heap, memory-mapped key-value store for Java with microsecond latency and cross-process sharing.

Microsoft Research's .NET cache-store that speaks RESP and scales across cores and storage tiers.

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

Embedded Java database exposing concurrent Maps, Sets and Queues backed by disk or off-heap memory.

Tencent's mmap-backed key-value store for mobile apps, built as a faster SharedPreferences/NSUserDefaults.

Qihoo 360's Redis-compatible, RocksDB-backed store for datasets too big for memory.

Google Cloud's managed in-memory family: Valkey, Redis, Redis Cluster and Memcached.

Broadcom's commercial in-memory data grid, the enterprise build of Apache Geode.

Globally cached, eventually consistent key-value store for read-heavy data at Cloudflare's edge.

Embeddable in-memory key/value store for Go with ACID transactions, custom and spatial indexes, and TTLs.

Pure-Go embedded key-value store with Bitcask storage and Redis-like lists, sets and sorted sets.

Redis-protocol NoSQL server that keeps strings, hashes, sorted sets and lists on disk in LevelDB.

Netflix's memcached-based distributed cache with zone-aware replication, built for AWS microservices.

Netflix's Dynamo-style proxy layer that adds sharding and multi-datacenter replication to Redis and Memcached.

A durable, Valkey/Redis-compatible in-memory database on AWS backed by a multi-AZ transaction log.

Embedded Go key-value store tuned for read-heavy workloads, using linear hashing and an mmap'd index.

Yahoo's embedded Java key-value store: off-heap index of every key plus append-only data files.

Yahoo's memory-mapped, zero-copy key-value library, a heavily tuned descendant of SGI's DBM.

Embeddable C datastore with 70+ Redis-like commands and a single-file ACID key-value store.

FAL Labs' C++ DBM library with hash and B+tree files; superseded by its author's Tkrzw.

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

Embeddable persistent and in-memory key-value engine for the JVM with typed Scala and Java APIs.

Tongue-in-cheek but working C/Go key-value store: mmap hash table, LZ4, splay-tree cursors and a REST API.

A copyleft (LGPL) fork of Redis 7.2.4, now limited to security backports.

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

Experimental lock-free in-memory MVCC key-value store for Go built on a Bw-tree; untouched since 2016.

Distributed JCache and memcached-compatible key-value cache built into Caucho's Resin Pro app server.

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

IBM's Java in-memory data grid for caching, HTTP sessions and partitioned object storage; still patched.

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

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

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

A wire-compatible SQL cache for Postgres and MySQL that keeps cached queries fresh from replication.

Shared-nothing, auto-sharded in-memory MySQL engine built for telecom-grade availability.

Oracle's in-memory relational database: microsecond SQL, PL/SQL, and a cache tier for Oracle Database.

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

The commercial, enterprise-hardened distribution of Apache Ignite for low-latency SQL and compute.

Low-latency in-memory plus on-disk SQL database with HotStandby failover, sold today by UNICOM.

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

Pioneering C++/Java object database that maps persistent objects into virtual memory; now sold by IgniteTech.

SQL Server's built-in lock-free, memory-optimized OLTP engine with natively compiled T-SQL.

Expensify's WAN-replicated SQLite server with Paxos leader election, MySQL protocol and job/cache plugins.

Frank Denis's in-memory, persistent store for geographic points and key/value records with an HTTP/JSON API.

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

An incremental view engine that keeps complex SQL results fresh inside your existing Postgres or MySQL.

C++ rewrite of Cassandra with shard-per-core design; also speaks the DynamoDB API.

A Postgres-compatible operational data warehouse that keeps SQL views incrementally up to date.