Having played with mod_perl and PHP and having battled with explat,
let me chime in w/ a few words of wisdom that have been noted in other
projects:

> XMLParser relies on Expat, which is a fine and august XML parser.  If the 
> license permits including Expat with Ruby, that might be the way to go.

It's probably worthwhile to have ruby include the expat source, but
deciding whether or not the expat from the ruby src is used or whether
or not an external installation is used should be determined at
runtime (with the preference towards using the existing expat
library).  mod_perl and apache had a ton of problems until they
started doing this (ex: expat compiled into mod_perl, then an external
library loads expat as a SO: core dump).  My $0.02.  -sc


> One other thing to consider is that I haven't posted any changes to REXML 
> because I've been busy re-writing XPath.  With the next release, it should 
> be pretty close to fully conformant with the XPath spec, and will be 
> feature complete. XSL processors require a fairly robust XPath 
> implementation to be implemented properly.

You just made my day.  <sobby_bud_commercial>I love you
man!</sobby_bud_commercial>  -sc