Gnome and KDE has their own window managers, namely Metacity and KWin. These can be replaced by other window managers, like Xmonad, and you can still use the Gn

Gnome and KDE has their own window managers, namely Metacity and KWin. These can be replaced by other window managers, like Xmonad, and you can still use the Gnome/KDE infrastructure and utilities just as nicely.