After installation of ZM from ports there was problem with image/video streaming via http. Events were created and saved in /var/www/zoneminder/htdocs/events but I could not see it from neither Mozilla nor from Opera.
It was solved by editing file:
/etc/apache2/vhosts.d/default_vhost.include
DocumentRoot "/var/www/zoneminder/htdocs"
ScriptAlias /cgi-bin/ "/var/www/zoneminder/cgi-bin/"
<Directory>
all "localhost" replaced for "zoneminder"