title: Better XML viewing in Firefox
body: <p>When you view a simple XML document in Firefox, it goes to the standard XML display mode, where you can collapse subtrees, etc.  But it's pretty limited in functionality; there's nothing convenient like "expand all" and "collapse all" buttons, there's that annoying "This XML file does not appear to have any style information associated with it. The document tree is shown below" message at the top of the page. Are there any decent Firefox extensions that provide better XML viewing/manipulating/navigating?  I looked in the Mozilla extension repository but there didn't seem to be anything promising.</p>