Links
ISPConfig
ISPConfig manages webserver, mailserver, BIND DNS, proftpd + vsftpd FTP server, mySQL databases, spamassassin and diskquotas with an easy to use web interface.
RavenCore
The RavenCore Project is an Open Source hosting control panel aimed at making the most robust, secure, and reliable hosting software.
Webmin
Webmin is a web-based system configuration tool for OpenSolaris, Linux and other Unix-like systems.