Memcached by Roberto Zicari · Published January 1, 2011 · Updated February 16, 2014 Free & open source, high-performance, distributed memory object caching system. LINK
Hypertable January 1, 2009 by Roberto Zicari · Published January 1, 2009 · Last modified July 11, 2014
db4o as Storage Provider in Voldemort September 1, 2010 by Roberto Zicari · Published September 1, 2010 · Last modified February 16, 2014
vFabric SQLFire January 1, 2012 by Roberto Zicari · Published January 1, 2012 · Last modified February 16, 2014