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  • The Resource Description Framework (RDF) is a language for representing information about resources in the World Wide Web.
  • Originally RDF was primarily intended to represent metadata about Web resources, such as the title, author, and modification date of a Web page, copyright and licensing information about a Web document, or the availability schedule for some shared resource. However, by generalizing the concept of a "Web resource", RDF can also be used to represent information about things that can be identified on the Web, i.e. the semantic web.

Major RDF vocabularies

Content syndication and social software
  • RSS 1.0 which is not very popular, most RSS formats are not RDF since bloggers don't understand issues related to the semantic web :)
  • FOAF Friends-of-a-friend vocabulary for person networks
Semantic Web
  • OWL
  • SKOS (Simple Knowledge Organisation System)
  • SPARQL (Query language)

RDF basics

At its core, RDF has a simple relational data model: Subject - Verb - Object or expressed differently Predicate (Subject, Object)

  • Subject = The resource
  • Object = Value
  • Verb = Predicate = propriety = relation of the subjet with the object

Here is a typical RDF fragment

<?xml version="1.0"?>
 <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
          xmlns:mon_schema="http://tecfa.unige.ch/lib/mon_schema" >
 <rdf:Description rdf:about="http://tecfa.unige.ch/perso/staf/lattion/">
  <mon_schema:Creator>Stéphane Lattion</mon_schema:Creator>

It expresses a relation like this:

A simple ressource-author relationship

RDF and the semantic web

The RDF Software stack

The RDF software stack

The RDF bus

Software clients of the RDF bus

Turtle syntax

Since XML/RDF code is some verbose, writing it manually is fairly time consuming. The W3C team proposes a "textual syntax for RDF called Turtle that allows RDF graphs to be completely written in a compact and natural text form, with abbreviations for common usage patterns and datatypes" (Turtle - Terse RDF Triple Language, retrieved 15:31, 10 March 2008 (MET)).


<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
  <rdf:Description rdf:about="http://www.w3.org/TR/rdf-syntax-grammar"
		   dc:title="RDF/XML Syntax Specification (Revised)">
      <rdf:Description ex:fullName="Dave Beckett">
	<ex:homePage rdf:resource="http://purl.org/net/dajobe/" />

becomes in turtle syntax:

@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix dc: <http://purl.org/dc/elements/1.1/> .
@prefix ex: <http://example.org/stuff/1.0/> .

  dc:title "RDF/XML Syntax Specification (Revised)" ;
  ex:editor [
    ex:fullname "Dave Beckett";
    ex:homePage <http://purl.org/net/dajobe/>
  ] .



RDF Namespaces
Other RDF Applications


On-line validation

RDF-related web sites

Various to sort out


  • Eric Miller An Introductionto the Resource Description Framework (1998), D-Lib Magazine May 1998, ISSN 1082-9873, HTML
  • Manola Frank and Eric Miller (2004). RDF Primer, W3C Recommendation 10 February 2004, W3C.