FOAF vs. XFN

Submitted by robataka on Thu, 12/22/2005 - 17:43.

Well, that title is a bit misleading perhaps. I have been looking at the foaf thingie in the edit form for a user's
account. What this thing does, basically, is to grab the information from your profile, and your buddy list and create a
foaf file out of it. The first question is what, exactly, is a foaf file?

I have been only vaguely aware of FOAF(Friend Of A Friend) having seen it around before but have never really looked at it closely.
From the FOAF Project page:

The Friend of a Friend (FOAF) project is about creating a Web of machine-readable homepages describing people, the links between them and the things they create and do.

Okay, that's easy enough to understand. So the next question is what good is it? For what is it used?

Again, the FOAF Project page to the rescue. There is a link labeled FAQ on the site, which in reality is a link to aIBM's site and an article by
Edd Dumbill. Here is what Edd says about the potential
of FOAF:

FOAF has the potential to become an important tool in managing communities.
In addition to providing simple directory services, you could use information from FOAF in many ways. For example:

  • Augment e-mail filtering by prioritizing mails from trusted colleagues
  • Provide assistance to new entrants in a community
  • Locate people with interests similar to yours

The concept of FOAF becomes very interesting when thinking in context of "social networking". For a while, "social networks" were all the rage. But they were closed systems, that in order to join required an "invitation" to somebody already subscribed to that network. The development of an /xml/rdf vocabulary that is open and free allows you do implement similar concepts but under your control and not limited to any specific "social network". The article is well worth the read if you are interested in this type of thing.

However, being a wide reader of various blogs, and having implemented Wordpress for some
acquaintances, I am also aware of XFN, or XHTML Friends Network. From that page:

XFN™ (XHTML Friends Network) is a simple way to represent human relationships using hyperlinks. In recent years, blogs and blogrolls have become the fastest growing area of the Web. XFN enables web authors to indicate their relationship(s) to the people in their blogrolls simply by adding a 'rel' attribute to their <a href> tags, e.g.:

<a href="http://jeff.example.org" rel="friend met">...

There is a little more detailed introduction here. So what are the differences? Not
really sure, but there is a page on the XFN site just on that topic: http://gmpg.org/xfn/and/foaf.
And here is a short critique of XFN over at O'Reilly Network.

I should note that RealNEO supports FOAF, but not as far as I can tell XFN. So perhaps its not worth worrying about.

( categories: )

I think FOAF is very important

I think one of the real opportunities of building our regional social network is leveraging a common FOAF profile - developing a regional standard of what data will be collected and shared as the common FOAF file. If all sites are configured for the same FOAF profile, that data can then be shared. That, I believe, will ultimately be in LDAP. Is that what you see?

re: I think FOAF is very important

Norm,

Your comment suggests many thing in that very short comment.


To make the assumption, that seems to be indicated, that you were asking if
I saw LDAP as the final "solution". The short answer is maybe, maybe not.


XFN and FOAF are attempting to address one problem area where as LDAP is
addressing another. LDAP, which stands for Light Directory Access Protocol
is basically just that, a directory service in a client-server architecture.
So LDAP says who is Norm Roulet(he is a member of realneo with this email, title, etc).
XFN and FOAF, however, while they also contain those elements, rather focus on
describing the relationship between people, e.g. Norm of Realneo is a friend of
robataka of realneo. LDAP is much more static, basically due to the fact that it
is an implementation of X.500 directory protocol. The end user has very little control
over the content. XFN and FOAF, on the other hand, are almost exclusively (under ideal
circumstances) under the control of the end-user. For example, the XFN site says this:

Note that while values such as friend are defined to be symmetric, this does not require that links between blogs be of the same types. Here, Adam feels Brad is a friend, but Brad has classified Adam as an acquaintance.

So you can see that as they stand today, while they are related, they are addressing different problem areas.


But I also think your comment hints at some other things which need to be fleshed out. In particular,
the keywords being "our", "opportunity", "regional", and "social networking". Each of these are
critical to define. Without definining these, the discussion of technology is really irrelevant other
than personal interest.


Here are the questions we need to answer:


Who is "we" to which "our" refers?


What is the opportunity? Or rather, what is the problem we are trying to solve?


How does regionalism affect the solution and/or the problem? Regionalism as opposed to what?


How does "social networking" address the problem?