Caché Post-relational Database by Roberto Zicari · Published January 1, 2010 · Updated May 9, 2014 Intersystems A free, fully-functional, non-expiring, single-user version of Caché. LINK
GLASS a free ODBMS for the Seaside web framework January 1, 2009 by Roberto Zicari · Published January 1, 2009 · Last modified February 16, 2014
Perst. Open Source, Object-Oriented Embedded Database January 1, 2009 by Roberto Zicari · Published January 1, 2009 · Last modified March 12, 2019