NeoDatis is an open source Object Oriented Database. It is a real native and transparent persistence layer for Java, .Net, Groovy, Scala and Google Android. With NeoDatis you can store and retrieve your objects with a single line of code without the need of mapping your objects to any table. So NeoDatis will increase your productivity and let you concentrate on your business logic.
(see www.neodatis.org to get more informations about the project).
NeoDatis.com is the commercial company behind the NeoDatis Open Source Object Database and provides commercial support for it.