I have a local install of Apache / MySQL and PHP on Fedora Linux.
I know PHP is running ok as some of my websites are running fine and if I create a simple file I can see I am running PHP 5.4.1.
Searching Google brings up tons of hits where the issue is PHP is not running at all but that isn’t the case here – it’s only one site that displays as plain text instead of processing as php.
I’m sure it’s some kind of seeting in httpd.conf but have had a look and there is nothing obvious (to me anyway).
If some pages work and some don’t check if it’s a short_open_tag in php.ini issue.
(it allows for <? instead of only <?php)