A microformat is a data formating approach that allows a developer make information that is intended for an end user to be read by software also.

An example would be a contact information found in a web page. A developer can use a contact microformat to put that information on the page so that humans and softwares can read it.

<div class="vcard">

   <div class="fn">Kenney Jacob</div>

   <div class="org">Mobme Wireless Solutions</div>

   <div class="tel">+919846831128</div>

   <a class="url" href="http://www.kenneyjacob.com">http://www.kenneyjacob.com/</a>

 </div>

What you are seeing above is a Vcard microformat. Many such formats are available to present various kinds of information like contacts, calenders, reviews etc.

Microformats allows a machine read them and make sense out of that information.

So Is microformats the gateway to web 3.0, the semantic web.