Although federated search is catching on -- most notably , which supports it as a feature -- it's a long way from a Webwide phenomenon.

To help federated search gain traction, the World Wide Web Consortium (W3C) has developed that define a basic semantic infrastructure. They include the following:

• , which defines a standard language for querying and accessing data.

• and RDF Schema (RDFS), which describe how information is represented and structured in a semantic ontology (also called a vocabulary).

• , which provides a richer description of the ontology and also includes some RDFS elements.