Well, first thanks for the praise, I appreciate. And this is Open-Source, you can port the module to Java, provided there is a Java interface with expat (although I don't see one in the list of expat wrappers).
This reminds me that a few years back, around 2000 I think, I got an email from a PHP guy, who seemed to be quite new to the language actually, who wanted to port XML::Twig to PHP. So I sent him an email explaining the design of the module, what I thought would be easy to do, and what might be a little harder... that was a pretty long email... and that's the last I ever heard from him!
