Open Source Clustered Hosting Control Panel

there are only two that i know off.


Interworx
Interworx The InterWorx Cluster Panel (InterWorx-CP) is a dedicated server and load balanced cluster control panel.
InterWorx-CP allows you to easily manage your dedicated server and gives you the ability to incrementally expand your single server into a full blown load balanced clustering solution. InterWorx-CP is the only panel which allows this simple incremental expansion from single server to load balanced cluster. there's no need for any complicated setup, InterWorx-CP takes care of the details for you so you can focus on your business.



ISPConfig
ISPConfig Hosting Control Panel ISPConfig - ISP management and Hosting Control Panel. ISPConfig manages webserver, mailserver, BIND DNS, proftpd + vsftpd FTP server, mySQL databases, spamassassin and diskquotas with an easy to use webinterface for administrators, resellers and clients.
LayeredPanel LayeredPanel allows you to build a free hosting network on your server(s), giving you complete control over the operation, support and features. LayeredPanel was built with speed and low server loads in mind, two of the main drawbacks of many of the other expensive control panels on the market. Due to our focus on an optimized script you are able to host over 30,000+ accounts (and even more in server clusters!)