[zackmorris]

While a lot of smart people are looking at this, I wanted to ask: does anyone know of any viable projects that build semantic data from existing websites?

I have experience with Open Graph http://ogp.me/ and oEmbed http://oembed.com/ but something about humans having to manually categorize a site has never sat right with me. We should be able to grok structure from sites by how other sites refer to them, similar to what Google does. This may be related to open source search, I don't know.