Big thread at Hack The Planet about RDF. REL/REV tags ; comments about thinking of RDF primarily for representing graph structures (better than XML can do); an old Tim BL draft article comparing RDF and XML models; the [E4 Graph] library for graph-like data (from the author of Meta Kit); Tinder Box (which uses XML not RDF so far), Epin Ions (which uses RDF); using NTriples instead of XML for RDF (!)...