XML vs RDF
Edd Dumbill’s Weblog: Behind the Times
Edd discusses why he chose RDF over XML for the DOAP project.
It’s really a very good post and I urge you all to read it. There are two points in his point I want to run with.
First, his example of RDF/XML markup looks like normal XML. This is a very, very important thing - it looks absolutely nothing whatsoever like the horrible, horrible ugly syntax the W3C documents use for their examples.
Secondly, in the list of “For XML” points, Edd says:
It’s hard to lock an RDF vocabulary down, should you want to.
Locking down an RDF vocabulary is counterproductive. AIs and ontologies and all those other things you personally don’t care about can slurp up and annotate and derive useful information from an RDF vocabulary, and you get the benefits when you can pick up all those terms you understand in data all over the web, learning new things and perspectives as you go.
Everything we do involves change; our understanding of our data and the things we are trying to model changes, our requirements change, new people accessing our data bring exciting new viewpoints to our model. Locking down a vocabulary means you can’t assimilate new ideas. RDF is far more agile than, say, a SQL database, because it handles change so much more gracefully.
I think Edd’s work is a really good example of RDF as distributed XML. Note how DOAP defines all its own terms, then uses an ontology to map to other well-known vocabularies.