XAP, XACT Project File (.xap)
The XAP Developer file format
XACT (Microsoft’s cross-platform Xbox Audio Creation Tool) is known for saving its project files in the XAP format. The information in the XAP file is saved in a plain text format. Thus, they can be opened in any text editing program. However, the data found in the file should not be edited by hand since these changes may not be able to be interpreted by XACT.
Technical details of XAP files
XAP files save the intermediate form of data it receives from the XACT program. This includes a multitude of other files such as XWB (wave bank descriptions), XSB (sound banks) and XGS (global settings). XAP files are used to save project work-in-progress.