Some of the tools are simply editors for a particular technology (eg, Protégé), other provide complex services (eg, AllegroGraph. It must be said that the borderline between this category and Programming Environments can be a bit fuzzy.
RDF Translator is a multi-format conversion tool for structured markup. It provides translations between data formats ranging from RDF/XML to RDFa or Microdata. The service allows for conversions triggered either by URI or by direct text input. Furthermore it comes with a straightforward REST API for developers.
This specification defines the HTML microdata mechanism. This mechanism allows machine-readable data to be embedded in HTML documents in an easy-to-write manner, with an unambiguous parsing model. It is compatible with numerous other data formats including RDF and JSON.
A story about the Semantic Web Interviews with: Tim Berners-Lee Clay Shirky Chris Dixon David Weinberger Nova Spivack Jason Shellen Lee Feigenbaum John Hebeler Alon Halevy David Karger Abraham Bernstein