Of course, it's not modern RDF but RDF 1999, still eighteen million firefox 1.0 downloads where everyone can use things like the Mozilla Amazon Browser.
An upgraded version of RDF support maybe on the cards with XUL Templates - Next Steps: "OK, I think it's time to finally improve XUL templates. There have been numerous proposals out there about how to to do it, but no one can really agree on what the best approach is. There is generally consensus that there needs to be support for XML data as well as RDF, and/or other data formats. What there isn't consensus on is what the templates will look like and whether to use a different template mechanism for different kinds of data. Unfortunately, like most of Mozilla, no one is in charge of things, so while lots of ideas float around, nothing actually gets done...I'm hoping that by implementing it incremently we can see better templates sooner rather than later. In fact, I've already implemented one new feature for RDF based generation which will appear in the Linspire version of Nvu."
Points to XUL Templates on the Mozilla Wiki.
Nvu is a Frontpage/Dreamweaver like program for Linux, OS X and Windows.