XSLT to XHTML 1.1

It's not so evident how to generate a valid XHTML 1.1 document with an XSL transform and the MS parser, first you have to use the command line utility for example.  It is possible though, see:
http://www.gibbsgrp.com/business.htm .

The XML is http://www.gibbsgrp.com/business.xml and the XSL is at http://www.gibbsgrp.com/business.xsl .

PS.  Don't tell my brother-in-law, it's his website {:o