The hacks in this chapter are designed to be window manager- and desktop environment-agnostic (that is, they don't depend on any given window manager or desktop environment, such as Fluxbox, WindowMaker, KDE, GNOME, or XFce). For the most part, the hacks simply assume you are running a version of X11.
These hacks range from the relatively mundane (replacing the ugly gray startup background with a black background) to frivolous but exciting changes (customizing your mouse pointer to show animated graphics). You'll also learn two different ways to make your fancy Internet and/or multimedia keyboard work with X11, how to access programs remotely (even if they are running on different platforms), and how to add 3D effects and transparency to your windows.
X11, which also goes by the names X and X Windows, is the client/server graphics engine that runs almost all the desktop environments and window managers on Linux. Almost all Linux distributions used to include XFree86, a free software implementation of X11. However, the folks in charge of XFree86 changed their software license, which led to a political uproar, the magnitude of which led eventually to a fork of the XFree86 code, and a new version of X11 called Xorg or X.org. Xorg has many benefits besides the preferred license. It has built-in support for transparency and drop shadows, and it often takes a better approach to solving problems than XFree86. Virtually all Linux distributions have switched from XFree86 to Xorg, or are in the process of doing so, with the notable exception of Debian.
Most of the hacks in this chapter do not require that you have Xorg installed instead of XFree86, but some of the most visually impressive hacks (transparency, drop shadows, etc.) do require this. The custom-cursor hacks don't require Xorg, but they do require that you have at least version 4.3.0 or better installed if you are running XFree86.
If you are running Xorg, note that a few of these hacks are likely to be more stable on some environments. This is especially true of the hacks that add drop shadows and transparency. This is the first attempt at adding these features to the X Window System, and not all the quirks have been worked out. The Xorg programmers are improving these features very quickly. But don't be surprised if these two hacks crash one window manager and work almost perfectly on another.