To enable the php5 module please create a symbolic
link from /var/www/conf/modules.sample/php5.conf
to /var/www/conf/modules/php5.conf.

ln -s /var/www/conf/modules.sample/php5.conf \
	/var/www/conf/modules

The recommended php configuration has been installed
to /var/www/conf/php.ini.
 
Don't forget that the default OpenBSD httpd is chrooted
into /var/www by default, so you may need to create support
directories such as /var/www/tmp for PHP to work correctly.
