Memcached is a general-purpose distributed memory caching system used by many sites around. It is often used to speed up dynamic database-driven websites by caching data and objects in RAM to reduce the number of times an external data source (such as a database or API) must be read. Memcached runs on Unix, Linux, Windows and Mac OS X.
The memcached gem requires the following development libraries to be installed
sudo apt-get install libmemcached-dev libsasl2-dev
sudo gem install memcached