RDFa
RDFをXHTMLに埋め込む規格のこと
Microformats, a simplified approach to semantically annotate data in web pages
Open Graph protocol, a way to use RDFa to integrate web pages into the Facebook social graph
Microdata - another approach at embedding semantics in HTML using additional attributes
eRDF, an alternative to RDFa (now obsolete)
GRDDL, a way to extract (annotated) data out of XHTML and XML documents and transform it into an RDF graph
Schema.org, search-engine supported schemas for structured data markup on web pages that can be expressed as RDFa
RDFa - Wikipedia