Very odd. I have to admit, I've never seen this exact behavior before.
Does your webserver run other PHP scripts ? eg; has the .php file extention been associated with the PHP interpreter... or, is there even a PHP interpreter installed ?
I can tell this is an Apache webserver, but is it a Linux webserver?
Possibly your version of DNPL (2.0 I'm guessing) lacks the full PHP tags.
Check the index.php file and make sure it starts with <?php and not just <?
Most web servers allow both, but the short version may be disabled on yours.
Once the index.php actually does run, you'll find it doesn't really do much except redirect your browser to the actual script, the file named "directory" where you will likely encounter another error.
Check
this FAQ entry once the index.php actually runs.