Desktops & Window Managers
Linux allows you to run different desktops and window managers.
With a little work, you can actually run multiple desktops and window managers - all at one time. Visit my Multiple X Sessions page for more information.
Here are some of the more popular desktops and window managers:
KDE and Gnome come with openSUSE 10.3 Alpha 5.
KDE / Gnome / Xfce (My Page) / FVWM Crystal / MaXX (5dwm) / ROX
All of these come with openSUSE 10.3 Alpha 5 except Enlightenment and Fluxbox.
FVWM / Enlightenment (My Page) / WindowMaker / IceWM / Blackbox / Fluxbox (Download) / Openbox