Hello,

Cpanel is a popular web based admin tool for linux servers, it contains many popular required linux features out of the box, and we use this on our linux hosting.

You can find a demo here:

http://cpanel.net/demo/     (Domain Owners)

WHM is the root/reseller side of the same cPanel script, it contains the server admin, account creation and modification scripts and features, as well as controls for the server services.

You can find a demo here:

Reseller:

http://cpanel.net/demo/    (Root/Reseller Admin)

Thanks!