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
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.
This site is a complementary effort by people from the Linked Data community to support Schema.org deployment and usage with a special focus on Linked Data:
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 is a specification of a precise semantics, and corresponding complete systems of inference rules, for the Resource Description Framework (RDF) and RDF Schema (RDFS).
getSchema's RDFa Lite extractor is a REST web service to extract RDF [1] data from RDFa Lite [2] annotations and provide the semantic information as N-Triples [5] , N3 [3] and JSON [4].
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.