What ever happened to xml term?
http://www.xml.com/pub/a/2000/06/07/xmlterm/
http://sourceforge.net/projects/xmlterm/
Why cannot we replace printf with something that emits RDF or a semantically marked up stream of data that identifies the variable printed, the format used, the datatype and the context of that emission?
Then it would be really easy to make really nice xmlterms and other funky things.