Out of the box, only PHP files with extensions of ‘php’, ‘php5’ and ‘php4’ are handled and parsed as PHP. There might be reasons why you’d want other file types to be parsed as PHP too (e.g. if you have hundreds of historical files with a different extension). This is easy to do. To have e.g. all ‘*.html’ files processed and served as PHP, you’d put this into a .htaccess file:

AddHandler php5-fcgi .html

You can use ‘php4-fcgi’ instead for PHP4, and note that you can do this on a per directory basis too.