You need to set up apache to send *.php files to the interpreter. How to do this varies wildly depending on your distro, but generally you need to add at least:
Code:
LoadModule php4_module apache2-extramodules/libphp4.so
and:
Code:
AddType application/x-httpd-php .php
to the appropriate sections of httpd.conf. The examples I gave are for php4, but php5 should be similar. I suggest you use the php guide to help you with the specifics:
http://www.php.net/manual/en/install.unix.apache2.php