Redis, Hazelcast, Aerospike, SAP HANA, and NCache are the most popular tools in the category “In-Memory Databases”. “Performance” is the primary reason developers pick Redis over its competitors, while “High Availibility” is the reason why Hazelcast was chosen.
Open source (BSD licensed), in-memory data structure store
Open source lighting fast key-value database with advanced features
An extremely simple Golang-based in-memory KV store
An open-source distributed database, caching and processing platform
An in-memory, column-oriented, relational database management system
Clustering and highly scalable data distribution platform for Java
Flash-optimized in-memory open source NoSQL database
A fully managed, open source–compatible in-memory data store