In the march toward creating the semantic web, web content management systems such as Drupal (news, site) and many proprietary vendors struggle with the goal of emitting structured information that other sites and tools can usefully consume. There’s a balance to be struck between human and machine utility, not to mention simplicity of instrumentation.

With RDFa (see W3C proposal),  software and web developers have the specification they need to know how to structure data in order to lend meaning both to machines and to humans, all in a single file. And from what we’ve seen recently, the Drupal community is making the best of it.

Introducing RDFa

RDFa is a set of XHTML attributes meant in particular to augment visual data with machine-readable hints. In layman’s terms, RDFa was created to help machines understand what humans intuitively get while browsing around the web. The hints in this case will strike those familiar with microformats and the rel nofollow open standard as rather familiar.

Actually, RDFa goes beyond this, providing somewhat of a circular benefit. While this standard helps machines understand what humans see, it also has applications for providing metadata to augment content. Machines then display the augmented content and humans suddenly understand even better the context of what they’re seeing.

Continues @ http://www.cmswire.com