TopQuadrant's TopBraid™ products support RDFa, both as an input format (via third party RDFa readers), and as an output format, using an RDFa editor. Input supports HTML via jtidy. We are currently upgrading our RDFa editor to have better wysiwyg capabilities.
hAudio is a simple, open, distributed format, suitable for embedding information about audio recordings in (X)HTML, Atom, RSS, and arbitrary XML. hAudio is one of several microformats open standards. This document is a mapping of hAudio to RDFa.
Cognition is a parser for both “upper case Semantic Web” (RDF, RDFa) and “lower case semantic web” (microformats) technologies. It includes modules for exporting parsed data in a variety of formats, including RDF, vCard, iCalendar, Atom and KML.
In these Web 2.0-3.0 days, there is a lot of expectation for data publishers to offer their data through APIs, but there is no clear way to encode and query this data in a universal way. There are many ways of encoding information structure and semantics