Free Memcached Alternatives

Redis is a free and open-source, in in-memory data structure store that can be used as a database, cache or message broker. The project is community developed and released under the BSD license. Redis supports common data structures including strings, hashes, lists, sets, sorted sets with range queries, bitmaps, hyperloglogs, geospatial indexes with radius queries and streams.

Couchbase, originally known as Membase is an award-winning, open-source, distributed multi-model NoSQL and document-oriented cloud database. It is designed and optimized for interactive applications and may serve many concurrent users by creating, storing, retrieving, aggregating, manipulating and presenting data. Couchbase delivers unmatched versatility, performance, scalability, and financial value across cloud, on-premises, hybrid, distributed cloud, and edge computing deployments.

HyperDex is a free and open-source novel distributed key-value store. The database is developed by Robert Escriva at Cornell University and released under the BSD-3-Clause License. Due to its distributed nature, HyperDex is highly scalable and provides serializability consistency and tolerates a threshold of server failures.

KeyDB is fast, free, and open-source NoSQL database with full compatibility for Redis APIs, clients, and modules. The database was originally forked from the Redis code-base and has been improved to handle multithreading, memory efficiency, and higher throughput. KeyDB is now a fully multithreaded and allow many machine cores to operate a single node resulting in 5X the throughput of Redis (v5) and up to 3x the throughput of Redis (v6). KeyDB also includes Redis Enterprise such as Active Replication, FLASH storage support, and other features like direct backup to AWS S3.