Dragonfly

Dragonfly claims to be a modern Redis replacement — same API, same commands, but with a multi-threaded architecture that uses every CPU core instead of Redis's single-threaded model. The pitch: 25x more throughput, 80% less memory, drop-in compatible.

If you're running Redis and hitting single-thread bottlenecks, Dragonfly is worth benchmarking. It's API-compatible, so migration is theoretically seamless. Valkey is the community fork of Redis after the license change. KeyDB is another multi-threaded Redis fork. Redis itself is still the default with the largest ecosystem.

The catch: The BSL-style license means you can't build a competing caching service. Independent benchmarks tell a different story than Dragonfly's marketing — Redis actually beat Dragonfly by 18-40% in some tests. The multi-threaded advantage only matters at very high throughput. For most indie projects, Redis or Valkey on a single core is more than enough, and the ecosystem support is vastly deeper.