Chicken and egg. When I look at today's Web, I see precious little metadata. We mine the scraps we have — email addresses, URLs, HTML metatags — for all they're worth. We know intuitively that with more and richer metadata, we could build more and richer applications. People much smarter than me imagine what it would be like if machines could “reason” about the things described with metadata. I'd love to see those people get the chance to do their experiment. So would Tim Bray, who also thinks the Web is “terribly metadata-thin” and has issued a challenge to produce a killer app for RDF (Resource Description Framework). … [Jon's Radio]