But then, what is the upside of using this versus using perl + XML::LibXML for example?
I understand that you simply offer custom functions, and that the users only have to know XSLT and those functions, not Perl in general, but is it really worth it? Is it so much easier to code XML processing in XSLT? Or is it a way to take the full power of Perl off the hands of inexperienced coders, using XSLT as a way to limit what they can do? That is a real question by the way, not a devious way to put down XSLT ;--)