Two years or so, we had a talk about the Semantic Web by Stéphane Corlosquet, who was one of the contributors to Drupal core in the area of Semantic Web.
Now that Drupal 7 has been out for a while and has this feature out of the tar.gz file, it is time for a recap, specially that we do have a large user, University of Waterloo, who use the Semantic web on their Drupal sites.
Schema.org is a joint initiative from the major search engines to build a collection of schemas that webmasters can use to markup their HTML pages.
Search engines including Bing, Google, Yahoo! and Yandex rely on this markup to improve the display of search results, making it easier for people to find the right web pages. Drupal 7 makes it easy to markup pages withschema.org, allowing to quickly build pages with structured data that can be understood by Google and displayed as Rich Snippets.
Stephane is a Software engineer and Drupal developer at MIND Informatics.
Drupal Module: http://drupal.org/project/schemaorg