I've recently been a huge fan of XDoclet2, and when confronted with some issues in the original XDoclet code recently, I decided that it was time to convert Dentaku over to see what would happen. XDoclet2 is very easy to write plugins for, and since Gentaku is based on Generama (the root module for XDoclet2), it made sense to port over to it. I'm happy to say that this conversion was a success and the fruits of that are checked into CVS.
While X2 was designed such that the metadata implementation is pluggable, the fact is that opaque Objects are returned from the metadata provider, and these Objects are cast at runtime after a bit of type checking. But that binds the generators to the QDox metadata provider. In the near future, watch this space as we refactor the existing XDoclet output modules to get their metadata information through a strongly typed interface, allowing the metadata source to be truly swappable.