One of the ways Mac OS X determines if a package is an application is through the use of file extensions. The rules to determine if a package is an application are:
On all file systems: the presence of a .app
suffix
On HFS+ only: the .app
suffix
is optional, if the package bit is set and the folder contains a
new style info.xml
.
© 2002, 2007 Apple Inc. All Rights Reserved. (Last updated: 2007-03-06)