In computer science and information science, an ontology formally represents knowledge as a set of concepts within a domain, and the relationships between those concepts. It can be used to reason about the entities within that domain and may be used to describe the domain.In theory, an ontology is...
A person is a human being, or an entity that has certain capacities or attributes strongly associated with being human , for example in a particular moral or legal context...
s, 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.
The Web Ontology Language is a family of knowledge representation languages for authoring ontologies.The languages are characterised by formal semantics and RDF/XML-based serializations for the Semantic Web...
(OWL). 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 yours know. This is accomplished by defining relationships between people. Each profile has a unique identifier (such as the person's e-mail address
E-mail address
An email address identifies an email box to which email messages are delivered. An example format of an email address is lewis@example.net which is read as lewis at example dot net...
Extensible Messaging and Presence Protocol is an open-standard communications protocol for message-oriented middleware based on XML . The protocol was originally named Jabber, and was developed by the Jabber open-source community in 1999 for near-real-time, extensible instant messaging , presence...
In computing, a uniform resource identifier is a string of characters used to identify a name or a resource on the Internet. Such identification enables interaction with representations of the resource over a network using specific protocols...
of the homepage or weblog of the person), which is used when defining these relationships.
The FOAF project, which defines and extends the vocabulary of a FOAF profile, was started in 2000 by Libby Miller and Dan Brickley. It can be considered the first Social Semantic Web
Social Semantic Web
The concept of the Social Semantic Web subsumes developments in which social interactions on the Web lead to the creation of explicit and semantically rich knowledge representations. The Social Semantic Web can be seen as a Web of collective knowledge systems, which are able to provide useful...
application, in that it combines RDF technology with 'Social Web' concerns.
The Semantic Web is a collaborative movement led by the World Wide Web Consortium that promotes common formats for data on the World Wide Web. By encouraging the inclusion of semantic content in web pages, the Semantic Web aims at converting the current web of unstructured documents into a "web of...
Giant Global Graph is a name coined by the inventor of the World Wide Web, Tim Berners-Lee in 2007, to help distinguish between the nature and significance of the content on the existing World Wide Web, and that of the next-generation web, or "Web 3.0"...
, where relationships transcend networks/documents. He considers the GGG to be on equal grounds with Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
The World Wide Web is a system of interlinked hypertext documents accessed via the Internet...
, stating that "I express my network in a FOAF file, and that is a start of the revolution."
WebID Protocol
The WebID Protocol (formerly known as FOAF+SSL) is a decentralized secure authentication protocol utilizing FOAF profile information as well as the SSL security layer
Transport Layer Security
Transport Layer Security and its predecessor, Secure Sockets Layer , are cryptographic protocols that provide communication security over the Internet...
available in virtually all modern web browsers. It was first presented for the W3C Workshop on the Future of Social Networking in 2009. Contrary to the usual SSL utilization patterns, it does not require the dedicated key signing parties such as Certificate authority
Certificate authority
In cryptography, a certificate authority, or certification authority, is an entity that issues digital certificates. The digital certificate certifies the ownership of a public key by the named subject of the certificate...
to perform the user authorization.
Deployment
Although it is a relatively simple use-case and standard, FOAF has had limited adoption on the web. For example, the Live Journal and DeadJournal blogging sites exports FOAF profiles for all their members, My Opera community exports FOAF profiles for the members as well as for the groups, the FOAF support is known to be present on Identi.ca
Identi.ca
identi.ca is an open source social networking and micro-blogging service. Based on StatusNet, a micro-blogging software package built on the OpenMicroBlogging specification, Identi.ca allows users to send text updates up to 140 characters long...
MyBlogLog was a social network for the blogger community that was based in part on interactions facilitated by a popular web widget that many members install on their blog. Bloggers signed up for free accounts on MyBlogLog and can initiate a blog community for one or more blogs they authored...
FriendFeed is a real-time feed aggregator that consolidates the updates from social media and social networking websites, social bookmarking websites, blogs and micro-blogging updates, as well as any other type of RSS/ Atom feed...
TypePad is a blogging service from company Say Media . Originally launched in October 2003, TypePad is based on Six Apart's Movable Type platform, and shares technology with Movable Type such as templates and APIs, but is marketed to non-technical users and includes additional features like...
services, as well as on various other ones. Yandex
Yandex
Yandex is a Russian IT company which operates the largest search engine in Russia and develops a number of Internet-based services and products. Yandex is ranked as 5-th world largest search engine...
blog search platform supports search over the FOAF profile information. The prominent client-side FOAF support is available in Safari
Safari (web browser)
Safari is a web browser developed by Apple Inc. and included with the Mac OS X and iOS operating systems. First released as a public beta on January 7, 2003 on the company's Mac OS X operating system, it became Apple's default browser beginning with Mac OS X v10.3 "Panther". Safari is also the...
web browser, in the Semantic Radar plugin for Firefox browser, and in the RDF Detective plugin for the Google Chrome
Google Chrome
Google Chrome is a web browser developed by Google that uses the WebKit layout engine. It was first released as a beta version for Microsoft Windows on September 2, 2008, and the public stable release was on December 11, 2008. The name is derived from the graphical user interface frame, or...
browser.
There are also modules or plugins to support FOAF profiles or FOAF+SSL authorization for programming languages, as well as for content management systems.
Turtle is a serialization format for Resource Description Framework graphs. A subset of Tim Berners-Lee and Dan Connolly's Notation3 language, it was defined by Dave Beckett, and is a superset of the minimal N-Triples format. Unlike full N3, Turtle doesn't go beyond RDF's graph model...
Jimmy Donal "Jimbo" Wales is an American Internet entrepreneur best known as a co-founder and promoter of the online non-profit encyclopedia Wikipedia and the Wikia company....
is the name of the person described here. His e-mail address, homepage and depiction are resources
Resource (Web)
The concept of resource is primitive in the Web architecture, and is used in the definition of its fundamental elements. The term was first introduced to refer to targets of Uniform Resource Locators , but its definition has been further extended to include the referent of any Uniform Resource...
, which means that each of them can be described using RDF as well. He has Wikimedia as an interest, and knows Angela Beesley (which is the name of a 'Person' resource).
The Web Ontology Language is a family of knowledge representation languages for authoring ontologies.The languages are characterised by formal semantics and RDF/XML-based serializations for the Semantic Web...
The social Web is a set of social relations that link people through the World Wide Web. The Social web encompasses how websites and software are designed and developed in order to support and foster social interaction. These online social interactions form the basis of much online activity...
The Semantic Web is a collaborative movement led by the World Wide Web Consortium that promotes common formats for data on the World Wide Web. By encouraging the inclusion of semantic content in web pages, the Semantic Web aims at converting the current web of unstructured documents into a "web of...
Description Of A Career is a semantic vocabulary created by Ramon A. Parada to describe professional capabilities of a worker. It has been designed to be compatible with the European curriculum so those can be generated from a FOAF+DOAC file...
Description of a Project is an RDF schema and XML vocabulary to describe software projects, and in particular open-source. It was created and initially developed by Edd Dumbill to convey semantically information associated with open-source software projects...
vCard is a file format standard for electronic business cards. vCards are often attached to e-mail messages, but can be exchanged in other ways, such as on the World Wide Web or Instant Messaging...
XHTML Friends Network is an HTML microformat developed by Global Multimedia Protocols Group that provides a simple way to represent human relationships using links. XFN enables web authors to indicate relationships to the people in their blogrolls by adding one or more keywords as the rel...
