Yes we do!
XML is a markup language like HTML.
XSL is a stylesheet language for XML documents.
XSLT is a language for transforming XML documents into other XML documents.
Since documents written in these languages are simply text files, they are fully supported on our servers.
Read more about these tools here: W3C Factsheet for XSL
The PHP library libxslt for XSLT processing is provided in PHP 4 running as CGI and PHP 5 running as CGI.
