DB4O Object Database...
By Mathieu CARBONNEAUX
Etonant versant editeur de base de données objet releases an embedded object database OPEN SOURCE!
It smells like a marketing stunt!
In any case, the product looks interesting… its only flaw is that being used in an embedded way, i.e. in the form of a library, and being GPL (and not LGPL), if you want to use it to develop a commercial product, you’ll have to use the commercial license…