There are three types of execute permissions on a website/virtual directory:
2) Scripts only
3) Scripts + Executable
Option 2 is a superset to 1.
Option 3 is a superset to 2.
To execute an interpreted script like perl/php etc., Option 2 is sufficient, provided a “script engine” check box is enabled in some dialog box in ISM. In our default configuration, the “script engine” check box is enabled and hence perl/php script will run with Option 2.