[development] XML transformations using XSL

[drupal]

> Yup. Using XSLT adds a hell of a lot more 'moving parts' than is  
> strictly necessary, and in general working with a database is far far simpler, and more  
> easily maintainable by a larger group of people.
Yep, and strictly speaking XSL is an overcomplicated beast - too general
for its own good. It can be useful is some specific cases, but within
drupal it is better to stick to php. It is a XML processing instruction
after all, hence the <?php ?>