Well , storing in a file is slow, I agree.

But you're not obliged to save the content you get in a file !
I don't know what kind of process you want to do with PHP, but with the 
solution I use I can process the original xml file before and after 
transformation by XSL.

So it's a matter of programming : either you use PHP to alter the original 
xml file then you transform the result with xsl and you send that to the 
browser; either you process the result of the transformation then send that 
to the browser.

So there is no overcost of saving in a file. And in both cases you get the 
benefice of gathering XSLT and PHP (in my opinion a very efficient pair of 
programming languages).

Actually, in my case, I did it because I want to store the final 
transformation as static xhtml files (not so static because I use Javascript 
on these pages to interact with the client).

Daniel

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list