As previously described, geo and h-geo are microformats for publishing geographical information. While reading a book about social media, one may ask whether geographical metadata falls into the description of social data. When thinking about geodata, the core idea to keep in mind is that geographical information can be exploited in so many applications. For example, users may want to perform a location-specific search for businesses (as in Yelp) or find pictures taken from a particular location. More in general, everybody is physically located somewhere or is looking for something physically located somewhere. Geographical metadata enables applications to fulfill the need for location-specific customizations. In the age of social and mobile data, these customizations open many new horizons for application developers.

Back to our journey through semantically marked up data, this section describes how to extract geographical metadata from web pages using Wikipedia for...