I must reluctantly put away the RDF and SPARQL modules for Drupal, at least for now. Both are very new, mostly undocumented, and support seems fragmented. I’ve tried for hours to get the SPARQL endpoint to work on this site, with no luck, and not sure who to ask for clarification.
I can read the code, but much of it focuses on the Drupal development. Until I’m more familiar with Drupal, looking through the code isn’t going to be overly useful.