Virtualmin is a very powerful and light control panel for Unix-based and of course Linux servers, written mostly in perl, being one of the favorites tools of administrators
The reason is simple, it very expandable and does not affect operating system on which is installed, unlike for example radical changes taking place by cPanel. The management is offered by it's own web server providing a web-interface for setting up all available services (Apache, NGINX, MySQL, PHP, mailserver, etc) and config files of the system.
