Unlike Windows, Linux separates the GUI into two modular
components, the graphical server and the window manager.
The server handles the display hardware and does the actual
drawing, while the window manager provides the "look and feel."
The
standard graphical server for UNIX is called the X-Window System (X11),
originally developed by MIT. The Linux implementation is called XFree86.
For a couple of years, the most common window manager for Linux was Fvwm (Virtual Window Manager, the "F" is silent), although many more have been available, including a Win95 lookalike. The SuSE CD's contain nine wm's at last count. This presentation uses Netscape, Fvwm2, X11r6, and Linux 2.0.32.
For the most part, though, two newcomers
have taken over the market: KDE
(K Desktop Environment) and GNOME (GNU Object Model
Environment). KDE is the default windowing environment on most
distributions as of late 1999;
GNOME just came out of
beta as v1.0 and is included on newer distributions.
Most Linux
users will wind up using one or the other,
since both can be made to "look and feel" much like MS Windows
and thus minimize the learning curve.
By the way, "GNU" and its derivatives like GNOME are pronounced with
a hard "G" sound -- "guhNEW", "guhNOME".