In a previous post I’ve highlighted the need of simple tools that can be easily accessed by a large number of users in order to
- ease the process of publishing and retrieving structured information
- show the value of having structured information on the web
Recently at Deri Giovanni Tummarello and his rsearch group has launched a service called Sigma which easily fits in these categories.
Sigma is a search engine for structured data based on Sindice.
Sindice parses the information on the web looking for RDFa and microformats, in particular it parses well known structured information in pages such as Wikipedia, Wordpress blogs, Linkedin, Flickr, Facebook, etc. retrieving information and translating it in triples.
Sigma presents this information and allows you to do some pretty cool stuff with it.
The key features are:
- a cool and meaningful visualization of triples including the related sources
- the great interface that allows you to add additional sources of triples and to create your own “views” of information about a resources (the so called sigmas)
The “sigmas” intended as “views” of information about particular resource can be shared, blogged, and downloaded as JSON or RDF.
Ok I must admin that Sigma isn’t probably an application “for the masses” but surely it has the great merit to show in a tangible way what it can be done with the Web of data.
I’ve played around a little bit with my name adding my blog as a source of additional RDFa and it was pretty easy and straightforward.
In the following you’ll find a snipped of the results returned form Sigma:
There is some funny stuff 
but one can easily reject the info and build his/her own “clean” sigma.
Learn more about Sigma here.
