What is X Windows?

Well, technically, ``X Windows'' doesn't exist. What you're probably referring to is X, the X Window System, X11. (The man page for X, pulled up by executing ``man X'', specifies acceptable names for X.) Some people get offended by the reference to ``X Windows,'' as if it were an offshoot of Microsoft Windows or something lame like that.

X is the premier graphics engine for UNIX-like OSes. It's very powerful for remote execution of programs (on local displays), and very configurable.

Part of this is because X itself is simply a graphics engine, as distinct from a Graphical User Interface, or GUI, which actually provides a mechanism for the user to interact with the system.

It provides services like mouse events and movements, keyboard events, and basic screen-drawing functions. Everything else is under the control of other programs, normally ``window managers,'' which have the role of presenting windows with widgets, starting new programs, handling virtual screens (as opposed to virtual desktops; screens are like different displays altogether, while virtual desktops allow you to have a larger desktop than your screen can actually display), and other functions - ie, an interface to the programmes running on the system. Which window manager is being used can be determined by each user, and each one has its own strengths and weaknesses.

Contrast this to the later versions of Microsoft Windows, where the GUI interface is fairly well all you get; Microsoft determines what you can do with it. Incidentally, there are two window managers that look fairly well like Windows, qvwm and fvwm95; there's also CDE, KDE, and Gnome which are more UNIX-like in features but aren't so far distant themselves. (I know; all those CDE purists out there just drew up a bounty on my head.)