FOAF (an acronym of Friend of a Friend) is a machine-readable ontology describing persons, their activities and their relations to other people and objects. Anyone can use FOAF to describe him or herself. FOAF allows groups of people to describe social networks without the need for a centralised database.
FOAF is an extension to RDF Resource Description Framework and is defined using OWL Web Ontology Language. Computers may use these FOAF profiles to find, for example, all people living in Europe, or to list all people both you and a friend of you know. This is accomplished by defining relationships between people. Each profile has a unique identifier (such as the person's e-mail addresses, a Jabber ID, or a URI of the homepage or weblog of the person), which is used when defining these relationships.
Tim Berners-Lee in a recent essay redefined the Semantic web concept into something he calls the Giant Global Graph, where relationships transcend networks/documents. He considers the GGG to be on equal grounds with Internet and World Wide Web, stating that "I express my network in a FOAF file, and that is a start of the revolution."
The following FOAF profile (written in XML format) states that Jimmy Wales is the name of the person described here. His e-mail address, homepage and depiction are resources, which means that each of them can be described using RDF as well. He has Wikipedia as an interest, and knows Angela Beesley (which is the name of a 'Person' resource).
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:foaf="http://xmlns.com/foaf/0.1/" xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"> <foaf:Person rdf:about="#JW"> <foaf:name>Jimmy Wales</foaf:name> <foaf:mbox rdf:resource="mailto:firstname.lastname@example.org" /> <foaf:homepage rdf:resource="http://www.jimmywales.com/" /> <foaf:nick>Jimbo</foaf:nick> <foaf:depiction rdf:resource="http://www.jimmywales.com/aus_img_small.jpg" /> <foaf:interest> <rdf:Description rdf:about="http://www.wikimedia.org" rdfs:label="Wikipedia" /> </foaf:interest> <foaf:knows> <foaf:Person> <foaf:name>Angela Beesley</foaf:name> <!-- Wikimedia Board of Trustees --> </foaf:Person> </foaf:knows> </foaf:Person> </rdf:RDF>
See also Edit
- Resource Description Framework (RDF)
- Web Ontology Language (OWL)
- Semantic Web
- Description of a Career (DOAC)
- Description of a Project (DOAP)
- XHTML Friends Network (XFN)
- The FOAF Project
- FOAF Specification
- RDFweb hosts the FOAF wiki
- Facebook Foaf Generator Generate FOAF descriptions from your Facebook profile
- FOAFexplorer HTML based FOAF Browser
- FOAF.Vix Visualizer and relation explorer for FOAF files
- FOAF+DOAC Project Homepage
- Advanced FOAF Explorer another XHTML based FOAF Browser
- FOAFer another HTML based FOAF Browser
- FOAFnaut SVG based FOAF Browser
- FOAF-a-matic Page to generate FOAF Descriptions
- Foaf-O-matic Web application to generate FOAF Description integrating globally unique identifiers
- FOAF Creator Page to generate FOAF Descriptions
- FOAFgen Convert LDIF/vCard collections to FOAF
- FOAF dataset a dataset of 201,612 FOAF triples
- Finding friends with XML and RDF, from IBMTemplate:Software-stub