What's this X thing then? X, the X-Window System, X11 (but the manual page asks you not to call it X-Windows) is what GNOME sits on top of. The Window part of the name is not associated with the MS Windows operating system: don't get confused by that! The X Window System is a open standard understood by many operating systems. It is used for drawing a graphical display on your computer. X is the native windowing system on all versions of UNIX and VMS. X servers are also available for Microsoft Windows and OS/2, even though these operating systems have their own proprietary windowing systems. X also allows an application running on one computer to display its output on another remote computer. Sometimes it's easier to think of X as a networking tool which happens to draw pictures. The reason this matters in a GNOME FAQ is that GNOME sits on top of X. You need X on your computer and working properly for GNOME to work. Sometimes things you may think are related to GNOME are in fact related to X: for example, some (but not all) font issues are related to X; the resolution of your screen is handled by X; and it's the contents of your X configuration file which tells X how to start GNOME. Networking? Why does this matter? Networking matters in X because it's part of what it was designed to do. If you have two connected machines, it's possible (and extremely simple) to sit at one machine and tell it to run the X server (which handles the display) on your machine, but to run X clients (the programs you actually see) from the other machine. So you can run the other machine's programs without moving to that other machine, which may be in the next room or miles away. Yes, this means that GNOME can do this too. Whilst you are using GNOME, you can also connect to other machines you have access to, and start GNOME programs there, and the results will be displayed on your machine. Where do window managers come into all this? What is a "GNOME-compliant" window manager and do I need one? The window manager is what decides how to display and move windows about. X gives you the ability to have windows on your screen. The window manager is what controls how they appear, how how move them about, and what the borders of the window look like. There are many many window managers out there. GNOME doesn't require you to use any one particular window manager and has no one "official" window manager. But you will get the most out of GNOME if you use a GNOME-compliant one. A GNOME-compliant window manager is one which co-operates with GNOME and understands information that GNOME sends the window manager. Fully or largely GNOME-compliant window managers include Sawfish (until recently known as Sawmill; many people still call it that) Enlightenment Window Maker IceWM Scwm FVWM (version 2.3) Previous versions of this FAQ also referred to a few more as putting the finishing touches to GNOME-compliancy: of these, the FAQ for Qvwm does not mention GNOME; and the AfterStep FAQ refers to being as GNOME-compliant as possible but prefers the AfterStep pager to those offered by GNOME. (Comments from users of these welcomed.) From a practical point of view, picking one of the definitely GNOME-compliant window managers is a good idea simply because most GNOME users and developers use them and you are more likely to get rapid answers from them due to familiarity. The currently in-vogue window managers appear to be Sawfish, which is specifically designed to work with GNOME, and Enlightenment, which was the first to be designed to be compliant and was widely shipped with GNOME. A resolute minority prefer the older but still popular Window Maker and FVWM window managers.