Application directory

They are currently used in RISC OS and the ROX Desktop, and also form the basis of the Zero Install application distribution system.

Similar technology includes VMware ThinApp, and the NEXTSTEP/GNUstep/Mac OS X concept of application bundles.

RISC OS relies on a file in the directory named !Help which is launched as if the user double-clicked on it when help is requested (and can be any format the system understands, but plain text and !Draw formats are common), while the ROX Desktop opens the application's Help subdirectory.

Similarly, custom icons for the Application Directory may be contained within it—either .DirIcon (in any supported image format) or AppIcon.xpm under the ROX Desktop, or !Sprites and optionally !Sprites22 under RISC OS.

RISC OS application directories may contain a file named !Boot which is executed by the Filer either explicitly via the FilerBoot command, or when the bundle is first displayed (unless the user held Control when opening that Filer window, which defeats application booting[1]).

An example RISC OS application directory - !Draw
RISC OS: Contents of the !Draw application directory
RISC OS: Contents of !Draw's !Sprites22 file
RISC OS: !Draw's !Boot, !Run and !Help files