Sitezen is a widely used Sitebuilder that could be purchased and installed on a Cpanel server. The admin panel for sitezen could be accessed by IP/zenadmin OR Hostname/zenadmin, where you can manage the end users, reseller etc.

If you forget the password for the zenadmin user you can retrieve it by going into mySQL as root.

mysql> use sitezen_master;
mysql> select password from administrator_table where user_id='zenadmin';