redis

Redis is an open-source, networked, in-memory, key-value data store with optional durability. It is written in ANSI C. The development of Redis is sponsored by Redis Labs today; before that, it was sponsored by Pivotal and VMware. According to the monthly ranking by DB-Engines.com, Redis is the most popular key-value store. The name Redis means REmote DIctionary Server.

https://en.wikipedia.org/wiki/Redis