In opening up the .xap file that is generated as output from a Silverlight application I've been tinkering with lately I noticed a file called 'AppManifest.xaml'. I've also noticed an option in the property pages for the Silverlight project that appears to allow you to otionally not output that file for the project. When unchecking that option, however, I get errors when running the application: "Invalid or malformed application: Check manifest".
What is the purpose of this file?