One huge problem with Friendster and MySpace and Orkut is that they are closed systems; it is very difficult or impossible to import your friendlists (as many have found, to their chagrin), or expand on a particular system's range of sharable information. XFN, which identifies human relationships in HTML, would change this.

Or, in other words:

XFN provides the basis for a world-wide distributed network of personal connections. Proprietary data-owning services like Friendster could be superceded by XFN crawling and searching sites —a sort of "Friendorati," as it were. The advantage of a Friendorati-style network is that it allows every individual to fully express themselves through personal weblogs and web sites, instead of to the limited degree permitted by a proprietary service's user interface.

Here's the intro:

XFN puts a human face on linking. As more people have come online and begun to form social networks, services such as Technorati and Feedster have arisen in an attempt to show how the various nodes are connected. Such services are useful for discovering the mechanical connections between nodes, but they do not uncover the human relationships between the people responsible for the nodes.

XFN outlines the relationships between individuals by defining a small set of values that describe personal relationships. In HTML and XHTML documents, these are given as values for the rel attribute on a hyperlink. XFN allows authors to indicate which of the weblogs they read belong to friends, whom they've physically met, and other personal relationships. Using XFN values, which can be listed in any order, people can humanize their blogrolls and links pages, both of which have become a common feature of weblogs.

In sufficiently modern browsers, authors using XFN can easily style all links of a particular type; thus, friends could be boldfaced, co-workers italicized, and so on. It is also the hope of the authors that this practice becomes widespread enough to allow the creation of a service that charts personal (as opposed to purely mechanical) links between weblogs and the people responsible for them.

Interesting, hm?

[via nrdy Monstrepo]