Memcached

Redis

redis/redis

Popular

In-memory data store for caching, queues and pub/sub; back to open source (AGPLv3) since Redis 8.

Valkey

valkey-io/valkey

Trending

Linux Foundation, BSD-licensed fork of Redis adopted by AWS, Google Cloud and major Linux distros.

Dragonfly

dragonflydb/dragonfly

Rising

Multi-threaded, Redis- and Memcached-compatible in-memory store built for high throughput.

Garnet

microsoft/garnet

Microsoft Research's RESP-compatible cache store in .NET with high throughput and low latency.

Caffeine

ben-manes/caffeine

Popular

High-performance in-process caching library for Java, successor to Guava's cache.

KeyDB

Snapchat/KeyDB

Legacy

Multi-threaded Redis fork from Snap; development has slowed and Valkey/Dragonfly are preferred.

etcd

etcd-io/etcd

Popular

Strongly consistent distributed key-value store (Raft) that holds Kubernetes cluster state.

RocksDB

meta/rocksdb

Embeddable LSM-tree key-value engine from Meta, used as the storage layer of many databases.

FoundationDB

apple/foundationdb

Apple's distributed, ACID transactional key-value store used as a foundation for higher-level databases.