To start "gallery3" just browse to 

http://${VHOST_HOSTNAME}/${VHOST_APPDIR}/

and follow the simple instructions.

!!!   MAKE SURE TO CHANGE YOUR ADMIN PASSWORD !!!

Please have a look at the content of the .htaccess file.

I sugest to add "option -indexes" for the gallery directory
either in the .htacces or via apache config file
    

Please read the file http://${VHOST_HOSTNAME}/${VHOST_APPDIR}/README
for additional information.
For example, how to upgrade from gallery2 to gallery3.
    
For additional information refer to http://gallery.menalto.com/  please.