What is "memcachedb"

MemcacheDB (pronunciation: mem-cash-dee-bee) is a persistence enabled variant of memcached, a general-purpose distributed memory caching system often used to speed up dynamic database-driven websites by caching data and objects in memory. The main difference between MemcacheDB and memcached is that MemcacheDB has its own key-value database system based on Berkeley DB, so it is meant for persistent storage rather than as a cache solution. A version of MemcacheDB using LMDB is also available, offering greater performance. MemcacheDB is accessed through the same protocol as memcached, so applications may use any memcached API as a means of accessing a MemcacheDB database.

MemcacheQ is a MemcacheDB variant that provides a simple message queue service.

Active development of MemcacheDB seems to have currently stopped; the web page hasn't been updated since 2009.