Performing XQuery in Firefox via Berkeley DB XML

I've gotten a simple extension for Firefox going which leverages the 
open source Berkeley DB XML native XML database to be able to perform 
XQueries within Firefox (Currently only on Windows, but someone should 
be able to get it to work on other systems).

https://addons.mozilla.org/en-US/firefox/addon/5515

(Registration required at present until it gets through review---Reviews 
welcome!)

It's only a humble beginning (see the disclaimers), but I hope it can be 
of some use and interest...

best wishes,
Brett