Databases for Pub/Sub messaging

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

Raft-based, strongly consistent key-value store that holds Kubernetes' cluster state.

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

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.

In-memory relational database that runs your server logic as WASM modules and streams changes to clients.

Decentralised, offline-first graph database that syncs peer-to-peer in JavaScript.

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

A purpose-built event store for event sourcing, with streams, subscriptions and projections.

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

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

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

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.

AxonIQ's event store and message router for Axon Framework CQRS and event-sourced apps.

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

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.

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

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

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

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

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.

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

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

In-memory geospatial database and geofencing server that speaks the Redis protocol and HTTP.

Single-threaded stateful actors at the edge, each with its own strongly consistent SQLite store.

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

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

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