BerkeleyStorage is an experimental ZODB Storage using SleepyCat Software's Berkeley DB 2.x. You will need Berkeley DB 2.7.5 or later (I'm working with 2.7.7) (Note: 3.x is not supported yet) and the TCS.bsddb.db module from http://starship.python.net/crew/robind/python/ to use it.
This is a non-undo, non-versionable storage. Its prime advantage over dbmStorage is the reliability of Berkeley DB. You should be familar with running berkeley DB before using it, as well as know how to use custom_zodb. This is alpha. It seems to work for me, but for all I know, using it will cause the universe to explode. You have been warned. :-)