RDF

I don't get on well with the interfaces supplied with GraphDB, Stardog, RDFox or with TopBraid EDG or Eccenca.

Sure, all these interfaces allow interaction with the triplestores, but none of them come close to the direct representation of relational databases in tables.

The fact is that they are graph databases. And graphs are difficult to visualize. A fundamental advantage of graph databases is precisely the ability to display complex and networked information.