On the AnyExample.com website, there's a new tutorial showing how to create an XML-based website that uses XSLT for its templates.
XML and XSLT technologies provides standard ways of separation of presentation and data. This article contains an example of simple php "xslt engine" for XML driven web-sites which implements caching techniques and Apache-based XML file processing.
They start by setting up the web server to parse all XML file requests through a handler script using Apache's directives. Following thi ssetup, there's three code blocks, one for each of the "moving parts" of the sample application - the XML content, the XSLT template to style it, and the PHP to bring them both together.