Do you write HTML? You’ve just heard that Google now supports RDFa and you want to know where to start? Our own Steven Pemberton just published a fantastic RDFa introduction for HTML authors:
RDFa is a thin layer of markup you can add to your web pages that makes them understandable for machines as well as people. You could describe it as a CSS for meaning. By adding it, browsers, search engines, and other software can understand more about the pages, and in so doing offer more services or better results for the user. For instance, if a browser knows that a page is about an event such as a conference, it can offer to add it to your calendar, show it on a map, locate hotels or flights, or any number of other things.
Google just announced support for RDFa, starting with product reviews. Here’s Google’s FAQ on adding RDFa to your pages. This is a significant new direction for Google, where they will start looking at explicit data structure and provide enhanced search results accordingly. It’s fantastic to see them using RDFa for this task. It’s also fantastic to see them encouraging the use of a non-Google-branded vocabulary: open-vocabulary.org. Generic, reusable vocabularies built by industry groups, that’s exactly what we were hoping for with RDFa.
The side story here is that this was basically a Google-driven project from the start: they didn’t need the RDFa task force to create their vocabularies, to figure out how to mark up their pages, etc. Folks on the RDFa task force are finding out about this just now, as it happens. And we like it that way. RDFa is meant for communities of all sizes to mark up their pages, without centralized process overhead. Both Yahoo and Google’s RDFa launches were achieved without consultation with the RDFa community, and I consider that a success.
UPDATE: Google provides more details on RDFa for its rich snippets feature.
UPDATE 2: W3C blogs about the great news for structured web data.
Dan Connolly makes one of the more powerful arguments for truly web-extensible structured data in HTML, where you don’t need to ask for permission to innovate:
My view of Web architecture is shaped by episodes such as this one. While giga-scale deployment is always impressive and definitely something we should design for, small scale deployment is just as important. The Web spread, initially, not because of global phenomena such as Wikipedia and Facebook but because you didn’t need your manager’s permission to try it out; you didn’t even need a domain name; you could just run it on your LAN or even on just one machine with no server at all.
