One of the reasons I haven't been using RDFa in production is the problem of quality assurance (a.k.a. plain old html validation). Not because RDFa isn't valid markup as such, but the main tool I'm using during development is Marc Gueury's excellent HTML Validator Extension for Firefox. RDFa is valid XHTML+RDFa, but XHTML+RDFa is not HTML, so the extension reports dozens of errors starting with th ... Continue reading