Why does php work on our IIS6 server? [View all]

This is nothing critical (we are moving to IIS7), but I just was downloading some demo code, and did not realize php could run on our IIS6 server. I created this test.php file:

<?php
Print "Hello, World!";
?>

And yep, it works, displays "Hello, World!" on the webpage.

Under Web Service Extensions in IIS, I do not see PHP installed. Where else could I look to see where it is installed?

Thanks!