Valkey

Valkey is the Linux Foundation fork of Redis that stays truly open source. It's Redis, maintained by the community, with the same commands, the same data structures, and the same performance. Drop-in replacement.

Written in C, with Linux Foundation backing and contributions from AWS, Google, Oracle, Ericsson, and others. Forked from Redis 7.2.4, the last open source version, it's already diverging with its own improvements: multi-threaded I/O, RDMA support, and dual-channel replication.

Fully free. No paid tier from the Valkey project itself. Cloud providers (AWS ElastiCache, Google Memorystore) offer managed Valkey instances at their standard pricing. Self-hosting is trivial, same as Redis: a single binary, minimal config, runs on anything, and clustering follows the same architecture as Redis Cluster. Solo to large teams: free. Starting a new project and want an in-memory store? Valkey over Redis is the straightforward choice. Existing Redis users get an easy path too: migration is a config change. Point your client at Valkey and it works.

The catch: Valkey is young as a fork. The community is large and well-funded, but the project still needs to prove it can innovate independently, not just maintain compatibility. Some Redis modules (RedisJSON, RedisSearch) are not available in Valkey. You'd need alternatives for those specific features.