CHAPTER
11
THE X WINDOW SYSTEM
After reading this chapter and completing the
exercises, you will be able to:
S o far in this book, you have been working at the UNIX/Linux command
line or from a terminal window. UNIX and Linux also offer the ability to
use the X Window interface to provide a rich GUI experience for your work.
In this chapter, you learn about XWindow and about elements that can be used
with it, including Window Managers and desktops. You focus on learning the
popular GNOME and KDE desktops, including using windows, the Nautilus
application in GNOME, Konqueror in KDE, and personalizing your desktop.
563
,564 11 The X Window System
WHAT IS THE X WINDOW SYSTEM?
The XWindow System is a GUI that runs on Linux and many UNIX operating systems.
Like Windows and Macintosh operating systems, it provides an easy-to-use, graphical
method of operating the computer. Programmers can also develop applications that run on
the X Window System and support GUI components, such as windows, dialog boxes,
buttons, and pull-down menus. Figure 11-1 shows an XWindow screen in Fedora using the
GNOME desktop with two windows open at the same time. Figure 11-2 shows an X
Window screen in Knoppix using the KDE desktop (you learn about the GNOME and
KDE desktops later in this chapter).
Figure 11-1 An X Window screen in Fedora using the GNOME desktop
, What Is the X Window System? 565
Figure 11-2 An X Window screen in Knoppix using the KDE desktop 11
The X Window System was originally developed at the Massachusetts Institute of Tech-
nology (MIT). It was created so different brands of hardware, running different variations of
UNIX, would all look and feel the same to the user. It was also designed to run applications
across a network consisting of different types of computers. The system developed at MIT,
currently in its eleventh version, is appropriately called X11. At this writing, seven releases
of X11 are available, with the current release called R7.2.0 (X11R7). To find out more
about X11, go to the source at www.x.org. You can also download the latest version at this
Web site.
XFree86 is a free version of X11 that was ported from non-PC-based UNIX computers to
run on PCs. XFree86 is compatible with Linux, which is commonly used on PCs. You can
learn more about XFree86 and obtain the latest release at www.xfree86.org.
When you port software, you are adapting it from one type of computer or
operating system to run on a different computer or operating system. A
significant advantage of UNIX/Linux systems is that the operating systems and
the associated software are generally adapted to work in nearly the same way
when moved from less powerful (Intel-type) computers to more powerful
computers (RISC-based or even mainframes), and vice versa. This characteristic
is called scalability—the ability to port software to more or less powerful
machines.
Fedora, Red Hat Enterprise Linux, SUSE, and Knoppix are Linux systems that
combine features of XFree86 and X11R7.
, 566 11 The X Window System
X WINDOW CLIENTS AND SERVERS
Although you can easily use the X Window System to run programs stored on your local
computer, you can also run applications over a network. X Window uses a client/server
model in which a program can run on one computer but display its output on another. For
example, suppose you have a network with two computers: system A and system B. On
system A, you can start and run a program that resides on system B. Although you see the
program running in a window on system A, it might actually be executing on system B. This
interaction is transparent to you on system A; you might not know the program is actually
running on a different computer. In addition, systems A and B can be different types of
computers, each running a different variation of UNIX/Linux.
In X Window network terminology, the underlying desktop system from which you run a
program is called the X server. The system that hosts and executes the program is called the
X client.
In normal network terminology, the server is the system that hosts a program,
and the client is the system that is run by the user. In X Window jargon, the
terms client and server mean the opposite. The terms are reversed because the
X Window server (on the desktop) performs operations requested by the client
(on the host system). For example, the client might request that the server
display a window or ask the server to move a window to a different position on
the screen.
Two popular X server approaches for Windows-based PCs are X-Win32 and X-Win32
Flash from Starnet Communications. Both of these systems enable a computer running a
Windows operating system, such as Windows XP or Vista, to remotely connect to a
UNIX/Linux computer. X-Win32 is software that is loaded onto the PC and X-Win32
Flash comes pre-installed on a flash drive that is plugged into a PC’s USB port.TheWindows
PC with this software displays an X Window type of GUI with windows, menus, and other
features. Also, the remote connection is handled through SSH for secure communications.
You can learn more about X-Win32 and X-Win32 flash at www.starnet.com.
Another popular X server system is Exceed from Hummingbird Connectivity.The Exceed
X server applications are targeted to enable remote GUI access to UNIX/Linux computers
for UNIX/Linux and Windows desktop users. Exceed also includes software for sharing
resources between systems using NFS (see Chapter 2, ―Exploring the UNIX/Linux File
Systems and File Security‖).Visit connectivity.hummingbird.com/home/connectivity.html to learn
more about Exceed.
11
THE X WINDOW SYSTEM
After reading this chapter and completing the
exercises, you will be able to:
S o far in this book, you have been working at the UNIX/Linux command
line or from a terminal window. UNIX and Linux also offer the ability to
use the X Window interface to provide a rich GUI experience for your work.
In this chapter, you learn about XWindow and about elements that can be used
with it, including Window Managers and desktops. You focus on learning the
popular GNOME and KDE desktops, including using windows, the Nautilus
application in GNOME, Konqueror in KDE, and personalizing your desktop.
563
,564 11 The X Window System
WHAT IS THE X WINDOW SYSTEM?
The XWindow System is a GUI that runs on Linux and many UNIX operating systems.
Like Windows and Macintosh operating systems, it provides an easy-to-use, graphical
method of operating the computer. Programmers can also develop applications that run on
the X Window System and support GUI components, such as windows, dialog boxes,
buttons, and pull-down menus. Figure 11-1 shows an XWindow screen in Fedora using the
GNOME desktop with two windows open at the same time. Figure 11-2 shows an X
Window screen in Knoppix using the KDE desktop (you learn about the GNOME and
KDE desktops later in this chapter).
Figure 11-1 An X Window screen in Fedora using the GNOME desktop
, What Is the X Window System? 565
Figure 11-2 An X Window screen in Knoppix using the KDE desktop 11
The X Window System was originally developed at the Massachusetts Institute of Tech-
nology (MIT). It was created so different brands of hardware, running different variations of
UNIX, would all look and feel the same to the user. It was also designed to run applications
across a network consisting of different types of computers. The system developed at MIT,
currently in its eleventh version, is appropriately called X11. At this writing, seven releases
of X11 are available, with the current release called R7.2.0 (X11R7). To find out more
about X11, go to the source at www.x.org. You can also download the latest version at this
Web site.
XFree86 is a free version of X11 that was ported from non-PC-based UNIX computers to
run on PCs. XFree86 is compatible with Linux, which is commonly used on PCs. You can
learn more about XFree86 and obtain the latest release at www.xfree86.org.
When you port software, you are adapting it from one type of computer or
operating system to run on a different computer or operating system. A
significant advantage of UNIX/Linux systems is that the operating systems and
the associated software are generally adapted to work in nearly the same way
when moved from less powerful (Intel-type) computers to more powerful
computers (RISC-based or even mainframes), and vice versa. This characteristic
is called scalability—the ability to port software to more or less powerful
machines.
Fedora, Red Hat Enterprise Linux, SUSE, and Knoppix are Linux systems that
combine features of XFree86 and X11R7.
, 566 11 The X Window System
X WINDOW CLIENTS AND SERVERS
Although you can easily use the X Window System to run programs stored on your local
computer, you can also run applications over a network. X Window uses a client/server
model in which a program can run on one computer but display its output on another. For
example, suppose you have a network with two computers: system A and system B. On
system A, you can start and run a program that resides on system B. Although you see the
program running in a window on system A, it might actually be executing on system B. This
interaction is transparent to you on system A; you might not know the program is actually
running on a different computer. In addition, systems A and B can be different types of
computers, each running a different variation of UNIX/Linux.
In X Window network terminology, the underlying desktop system from which you run a
program is called the X server. The system that hosts and executes the program is called the
X client.
In normal network terminology, the server is the system that hosts a program,
and the client is the system that is run by the user. In X Window jargon, the
terms client and server mean the opposite. The terms are reversed because the
X Window server (on the desktop) performs operations requested by the client
(on the host system). For example, the client might request that the server
display a window or ask the server to move a window to a different position on
the screen.
Two popular X server approaches for Windows-based PCs are X-Win32 and X-Win32
Flash from Starnet Communications. Both of these systems enable a computer running a
Windows operating system, such as Windows XP or Vista, to remotely connect to a
UNIX/Linux computer. X-Win32 is software that is loaded onto the PC and X-Win32
Flash comes pre-installed on a flash drive that is plugged into a PC’s USB port.TheWindows
PC with this software displays an X Window type of GUI with windows, menus, and other
features. Also, the remote connection is handled through SSH for secure communications.
You can learn more about X-Win32 and X-Win32 flash at www.starnet.com.
Another popular X server system is Exceed from Hummingbird Connectivity.The Exceed
X server applications are targeted to enable remote GUI access to UNIX/Linux computers
for UNIX/Linux and Windows desktop users. Exceed also includes software for sharing
resources between systems using NFS (see Chapter 2, ―Exploring the UNIX/Linux File
Systems and File Security‖).Visit connectivity.hummingbird.com/home/connectivity.html to learn
more about Exceed.
