Top 8 Non-Relational Databases
Oracle Berkeley DBFileMakerIBM IMSActian NoSQL Object DatabaseFoxProInterSystems CachéActian db4oObjectStore
It's a pretty good tool and there's a lot of support and there's a lot of people out there that know how to use it.
I have found its resilience to attack most valuable. It's really difficult to attack the software.
The database schema is easy to define, manipulate and duplicate with respect to objects.