Memcached by Roberto Zicari · Published January 1, 2011 · Updated February 16, 2014 Free & open source, high-performance, distributed memory object caching system. LINK
db4o as Storage Provider in Voldemort September 1, 2010 by Roberto Zicari · Published September 1, 2010 · Last modified February 16, 2014
Apache Cassandra January 1, 2011 by Roberto Zicari · Published January 1, 2011 · Last modified February 16, 2014