Now think of all of the concepts and relationships between them that are introduced in this statement. As a human, interpreting these is dead simple.
Microsoft is a company
C# is a computer programming language
Microsoft created C#
But, making it so that a computer program can reduce this statement to concepts and the relationships between them is difficult. It is indeed a harrowing task to make computers derive the same meaning from natural language that people do.
Enter the The Semantic Web. The Semantic Web wants to convert the Internet into a database; to make it so computer programs can understand concepts and relationships between concepts contained within in the natural language on web pages.
Microformats are an element of the Semantic Web that define concepts (but don't do a good job of defining relationships), and we've recently introduced them on active.com. Microformats "...are a set of simple, open data formats built upon existing and widely adopted standards" that make it possible to annotate a web page with metadata describing concepts contained within them. On active.com we've implemented the hCalendar microformat to annotate events.
Consider, for example, the Carlsbad 5000. Peering into the HTML source, you'll find:
<h3 class="summary">Carlsbad 5000</h3>
<span class="dtstart" title="Sunday, April 05, 2009 @ 7:05 AM">Sunday, April 05, 2009 @ 7:05 AM</span>
<span class="dtend" title="Sunday, April 05, 2009 @ 10:05 AM">Sunday, April 05, 2009 @ 10:05 AM</span>
<span class="location">Carlsbad, CA</span><span class="uid"></span></div>
By annotating the "class" name attributes within the HTML elements according to the hCalendar standard, we can let a computer program know there's an event called the "Carlsbad 5000" on this web page, its start time, end time and location. The Tails Export Firefox plugin, for example, is a computer program that detects microformats on web pages. In the screenshot below we can see it detecting the hCalendar microformat on the Carlsbad 5000 event page:
This stuff's a little geeky sure. But we're proud to contribute to the Semantic Web! on active.com to come.