Anything To Triples (any23) is a library, a web service and a command line tool that extracts structured data in RDF format from a variety of Web documents.
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].
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 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: