Turn your face away
from the garish light of day, ...
-Charles Hart, The Phantom of the Opera
The good news is that there is graphical user interface (GUI=gooey) for Unix workstations, which runs on machines from all manufactures, and has many of the nice mouse and graphical features found on the window environments of PCs. This standard system is called The X Window System, or ``X'' for short. It was developed at MIT and is supported by a consortium of industry leaders, including DEC, Hewlett-Packard, Sun, IBM, and AT&. The bad news is that the documentation for X does not lend itself to a casual perusal while searching for a piece of needed information. To be fair to the casual peruser, even the serious user may get confused after facing the extent of the documentation with its continual revisions and the complication of the local blending of hardware and software. Nevertheless, the X Window System works very well, is pleasant, improves your working efficiency, and by becoming the standard user interface for all workstations, is very much helping make ``transparent computing environment'' a reality.
From an administrative point of view, the X of the X Window System might stand for eXtra large and eXtra heavy. The X program itself requires at least 25 MB of memory to get stored on your hard disk and at least 16 MB of random access memory to be run by your computer. And if that is not enough, X also puts significant demands on your workstation's processing power. As expected, meeting all these hardware requirements places eXtra demands on your pocket book.
There are several versions of X in existence to add to the challenge of X programming, and you should not be too surprised to find pieces of each running on any one machine. While it's commendable that the X consortium keeps turning out new versions every couple of years, it's overwhelming for the vendors to keep integrating the new releases into their products. The versions and releases of X currently in use are X11 R3, X11 R4, and X11 R5. These versions are not completely compatible, and so as you migrate from one to the next, you might be required to change your setup files and options.
The X Window System uses a client-server model for displaying graphics. Your display is considered the server when X is running on your display. The programs which place graphical objects on the display are clients of this server. As a consequence of the standardization of X, any machine on the network can open a window on your server and run a client-unless you are wise and knowledgeable enough to forbid it.
In this chapter we try to help the beginner get started with X and learn to take advantage of some of its many features. Along the way we present discussions and examples which should help the more experienced user personalize their X environment for that custom look. In concluding, we'll prove again one major advantage of a standard interface is that many programs and applications become available for it. A few of these applications are commercial packages, such as the symbolic manipulation programs, while most are freeware available over the network. Some of the free X applications have already been discussed in Chapter 3, Mail Systems.