RDFa, Microformats, and Microdata provide simple ways to enable semantic markup. Are there other similar technologies?
thank
RDFa and microdata are not very different things. All three formats do roughly the same thing in different ways, with RDFa and microdata very similar.
Read the Manu Sporny Uber Comparison of Three for more details: http://manu.sporny.org/2011/uber-comparison-rdfa-md-uf/
RDFa, Microformats and Microdata are actually very different things.
All 3 potentially provide a means to annotate HTML snippets
RDFa RDF HTML-, RDFa ( ).
, MathML RDFj, XHTML ( HTML5, ), - Javascript/JSON script.