Here's the description for the contest:

"db4o is a very fast well known object oriented database. So far, IntelliJ seems to support only Relational databases - but no Object oriented ones. There's an eclipse plug-in for db4o, so users will simply use Eclipse when their project is using db4o ."

Please vote so we can have a db4o plugin for IntelliJ IDEA !!

http://plugins.intellij.net/wishlist/item/?wid=352