(Windows only) Without this option, an attempt to close the A-Shell window by clicking on the "X" button or hitting ALT-F4 while a program is running, will display a dialog box warning you of the reasons why this might not be a good idea. If you ignore the warning and choose to abort anyway, the program will be aborted without any good chance of recovery. (See NOXABORT to prevent that possibility.) OPTIONS=XABORT presents a different approach by generating an ASB error #255 instead of displaying warnings. Then your ASB program can decide the best way to handle the situation, possibly by ignoring the error, possibly by closing the program gracefully and then exiting A-Shell.
