Maybe you have noticed how you are asked for root's password when you launch Synaptic, Yumex, or one of the Red Hat GUI system tools (system-config-*).
Maybe you have also noticed how (some releases of some) distros (Debian, Ubuntu) offer you either gnomesu (gnome-sudo), or gksudo (or gtksudo) as X front-ends to su, allowing you to run custom commands as root -- the most commmon use is to run Nautilus file manager as root.
Some other distros (Mandriva, Fedora) don't offer (anymore) any Gtk/GNOME su front-ends. Supposing you have installed KDE even if you're using another desktop environment, you may use kdesu instead.
But what if you don't have, or you don't want to use kdesu?
As it has been said, gnomesu/gksudo are not part of GNOME, nor officially supported by some distros because you can always use more advanced authentication methods, namely consolehelper, based on PAM (Pluggable Authentication Modules).
After a quick look at: man 8 consolehelper, man 8 userhelper, man 8 pam, and man 8 pam_console, and at the way other applications use PAM, I made my own way to add a "Root File Manager" icon in a distro that only has kdesu (which I will not use).
Full Story .