In terms of http://en.wikipedia.org/wiki/Linked_data , there are a number of standard (overlapping) URI-based schema for describing data with structured attributes:

* http://schema.org/docs/full.html

* http://schema.rdfs.org/all.json

* http://schema.rdfs.org/all.ttl (Turtle RDF Triples)

* http://rdfs.org/sioc/spec/

* http://json-ld.org/

* http://json-ld.org/spec/latest/json-ld/

* http://json-ld.org/spec/latest/json-ld-api/

* http://www.w3.org/TR/ldp/ Linked Data Platform TR defines a RESTful API standard

* http://wiki.apache.org/incubator/MarmottaProposal implements LDP 1.0 Draft and SPARQL 1.1