.XAP File Extension
File Type 1XACT Project
What is a XAP file?
Project created with the Microsoft Cross-Platform Audio Creation Tool (XACT); saved in a text format and contains the intermediate form of the information produced by XACT; includes complete descriptions of wave banks (.XWB files), sound banks (.XSB files), and global settings (.XGS files).
XAP files can be opened and viewed in a text editor, but they should not be edited manually. Instead, project files should only be modified with XACT.
File Type 2Silverlight Application Package
.XAP File Association 2
Application package originally created for Microsoft Silverlight (a Web browser plug-in enabling rich media content) but now also used for Windows Phone 7 mobile applications; includes a .XAML file named AppManifest.xaml and may include .DLL files reference by the software; stored in the .ZIP format.
XAP files are commonly used for distributing Windows Phone 7 applications.