Webmin is a web-based interface for managing any Unix / Linux server
Webmin is a web-based interface for system administration for Unix. Using any modern web browser, you can setup user accounts, Apache, DNS, file sharing and much more. Webmin removes the need to manually edit Unix configuration files like /etc/passwd, and lets you manage a system from the console or remotely.
I've been using Ajenti up to now to manage one of my Virtua;l Private Servers but have just tried Webmin and must say I love the level of detail and alerting that can be set up. It was also just one click to install a MySQL database.
It's installation was just as easy... execute installation and just login with a browser and that was it.
More details on Webmin at http://www.webmin.com