you need a webserver , it neednt be apache though most here would recommend it
you can run php from the command line but not for web related stuff which is what I assume you want to do
php as an apache module is about as popular as it gets though sambar( www.sambar.com ) runs a mean php (+other stuff) or search for omnipro or xitami or badblue which all run PHP as a CGI and are a little easier to set up.