Works best with well-written long-form prose (not well for tweets).
Puts the document into topic.
17 now, will probably go up to 300 and stop there.
semantic web compliant format: RDF
Then goes a step farther. For a subset, takes you into the linked data world. Another emerging standard, a Tim Berners-Lee initiative
for instance dbpedia
CIA World Factbook
now OpenCalais
Calais is a web service. Hard to demo.
When machines are talking to machines, usually takes us half-a-second to process a normal news article.