RDF is a graph data model that has been around since 1997. It's a W3C standard, and it's used to power schema.org and Open Graph, among other things. Plus, there's a bunch of RDF-based graph databases ...
I've been trying to approach the RDF thing a few times already. I'm not interested in some abstract, utopian ideas like Semantic web, just practical applications of ontologies/rdf in large ...