For Topicalla, I created a more sophisticated RDF templating language than the one XUL has. It uses ReoPath expressions to bind RDF data to XUL elements. It will also work for XHTML and other XML languages.
The implementation isn't finished; some tags don't work, and the auto-updating of the display when the RDF is changed hasn't been extensively tested.
However, here is a ReoPath Templates Specification.