A set of simple, open data formats built upon existing and widely adopted standards. From: http://microformats.org/about/

Wat kun je ermee doen?

Microformats make it easy for you or anyone to share and reuse data in your webpages and content elsewhere — for example, to populate an address book, browse social relationships, share reviews, tag content or publish and discover events. From: Chris Messina

Relax, everything is deeply intertwingeld: Microformats
Duncan Cragg: Microformats Challenge Web Feeds and Web APIs!
Technorati Microformats Search Beta | introductie
Tantek Çelik What are Microformats?