Leopard (10.5) was the first release of MacOS that included PHP 5 support. However by default it is disabled.
To enable it you need to uncomment (remove the #) from the following line in /private/etc/apache2/httpd.conf.
#LoadModule php5_module libexec/apache2/libphp5.so
Then restart apache
sudo /usr/sbin/apachectl restart
MacOS caches the result of DNS lookups to improve performance. If you wanted to flush this cache you used the following command with Tiger:
With the release of Leopard the required command changed to the following:
By default you can find the document root for Apache on a Mac (Leopard) in the following location.