Watch a recording of the webinar 'Contracts and Charms in Windows 8' delivered by Silverlight MVP Gill Cleeren on April 24th, 2012.
Webinar summary: In Windows 8 Metro, applications don’t communicate directly with each other. The OS has built-in contracts available out-of-the-box which make it possible that applications interact with each other without knowing each other. This way, one application can expose its own data for others to read. Another contract makes it possible to expose a common search functionality from within an application.