The Window Manager

Unlike the Macintosh and Windows environments, X makes the window manager a separate process. In fact, a window manager is merely an X application program, although it’s a special application. By separating the windowing system from the window manager, you are free to run any window manager that suits your needs. The main purpose of a window manager is to control how you move and resize windows on your Linux display. The window manager also creates the titlebar at the top of your application windows.

The key concept if you’re new to X is that the window manager—not the application—owns the window’s titlebar. This is really odd if you come from the Windows or Macintosh worlds. To show this, we’ll run the same X application, xman (which displays UNIX online manuals—a very useful program, indeed), under different window managers.

The fvwm window manager provides a vaguely Motif-like look for the window titlebars, as we show in Figure 3.1.

Figure 3.1  Xman running under the fvwm window manager.

If we switch to olwm, we see an Open Look visual display, as shown in Figure 3.2.

Figure 3.2  Xman running under the olwm window manager.

If we switch yet again, to twm, we see yet another look for the titlebar of the application, as shown in Figure 3.3.

Figure 3.3  Xman running under the twm window manager.

With all three window managers, the xman program itself looks the same; it’s only the window-manager-controlled titlebar that’s different.

X also follows the policy of providing the means to do neat things—the mechanism—without making any decisions about what is good for the user—the policy. This mechanism without policy approach has led to a great deal of innovation in the X and UNIX worlds, but at a price of difficult-to-configure, poorly done interfaces across the board. Slackware Linux comes with a number of window managers, including those listed in Table 3.1, and we’ve taken the liberty of adding a few free window managers to the second CD-ROM. (Unless noted otherwise, all the window managers here are part of the core Slackware Linux distribution.) You’re free to choose the window manager you desire and change at any time.

Most commercial UNIX systems run mwm, the Motif window manager, or a close variant. You’ll find this on workstations from Hewlett-Packard, SCO, IBM, Silicon Graphics, and even Sun Microsystems (with the Common Desktop Environment). Because mwm (and the rest of Motif, including the programming libraries) is a commercial product, you won’t see mwm on Linux unless you purchase it separately (see Appendix A for details). Because something so fundamental to most UNIX systems remains different on Linux, this may make getting used to Linux harder, especially if you work on other UNIX systems. Because of this common problem, we’ll show you how to configure fvwm, the default window manager on Linux, to look and act more like the Motif window manager, to help make you feel at home on Linux. See the section on “Toward a Motif-Like Look and Feel” later in this chapter for the details.