By bblfish on May 17, 2007
Last week Jiri Kopsa pointed me to the very useful mozilla extension for microformats called Webcards. Install it, reboot, and Mozilla will then pop up a discreet green bar on web pages that follow the microformats guidelines. So for example on Sean Bechhofer page 1 vcard is detected. Clicking on that information brings up a slick panel with more links to other sources on the web, such as delicious if tags are detected, or in this case linkedin and a a stylish button that will add the vcard to one's address book .
Microformats are a really simple way to add a little structure to a web page. As I understand it from our experimentation a year ago  in adding this to BlogEd, one reason it was successful even before the existence of such extensions, is that it allowed web developers to exchange css style sheets more easily, and it reduced the need to come up with one's own style sheet vocabulary. So people agreeing to name the classes the same way, however far apart they lived, could then build on each other's work. As a result a lot of data appeared that can the be used by extensions such as Webcards.
Webcards really shows how useful a little structure can be. One can add addresses to one's address book, and appointments to one's calendar with the click of a button. The publisher gains by using these in improvements to their web site design. So everybody is happy. One downside as far as structure goes is that due to lack of namespaces support, there is a bottleneck in extending the format. One has to go through the the very friendly microformats group, and they have stated that they really only want to deal with the most common formats. So it is not a solution to any and every data needs. For that one should look at eRDF or RDFa extensions to xhtml and html. I don't have an opinion on which is best. Perhaps a good starting point is this comparison chart.
The structured web is a continuum, from the least structured (plain text), on through html, to rdf. For a very good but long analysis, see the article by Mike Bergman An Intrepid Guide to Ontologies which covers this in serious depth.
As rdf formats such as foaf and sioc gain momentum, similar but perhaps less slick, mozilla extensions have appeared on the web. One such is the Semantic Radar extension. Perhaps Webcards will be able to detect the use of such vocabularies in RDFa or eRDF extended web pages too, using technologies similar to that offered by the Operator plugin as described recently by Ellias Torres.
 note this does not work on OSX. I had to save the file to the hard drive, rename it with a vcf extension, before this could get added to Apple's Address Book.
 Thanks to the help of Anotoine Moreau de Bellaing (no web page?)
 I know, BlogEd has not been moving a lot recently. It's just that I felt the Blog Editor space was pretty crowded allready, and that there were perhaps more valuable things to do on the structured data front in Sun.