Overview

Facebook provides a REST interface:
- Send: GET/POST http://api.facebook.com/restserver.php?method=method.name&parameter1=value1&...
- Get: XML (obeys facebook.xsd) or JSON
Write stand-alone applications, or web applications that user can to his facebook page.
On web app. facebook will ping you every time.
Once you authenticate (user logs in) you have access to some of his private information.