XFN

XFN (The XHTML Friends Network) is one of several "microformats" supported by the microformats.org site and community (some others have their specs maintained on that site, but this one is actually maintained at a different site, GMPG.org), intended for the representation of information in a manner that is human-readable but can still be processed by machines.

The format specifies data giving the connections between people in a social network, in the form of XHTML of a standardized form which can be automatically processed while remaining usable as part of a HTML/XML document.

This format is attempting to fulfill one of the visions of Web founder Tim Berners-Lee, to make the Web a network of people just as much as it is a network of computers and documents.

Links

 * Official site with specs and examples
 * Introduction to XFN
 * microformats.org page on XFN
 * Some examples "in the wild" of XFN and hCard-supporting sites