An experience of ehcp user, (no mine):
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yes you can run on raspberry pi but you must install raspdebian iso to raspberry. The reslove problem : uninstall php-cgi and change to php5 in apache2:

this problem is for internal 500

~# dpkg -l |grep php5-cgi

if you see a result then do this:

~# dpkg --purge php5-cgi

then remove cgi apt-get remove php5-cgi

and then install php5 apache module

~# apt-get install libapache2-mod-php5

~# a2enmod php5