X-Windows Free-Windows

A brief history The X Window system, developed at MIT in the late 1980s, is rapidly becoming the industry standard windowing system for graphics workstations. The software is freely available, very versatile, and is suitable for a wide range of hardware platforms, from high-end microcomputers to mainframes.

Free Source Code X windows is a hardware-independent network-based window system which was developed at MIT. In strict legal terms, it is not a public- domain product, but the source code is freely available, and is available for virtually any workstation, mainframe or high-end micro.

Other windowing systems A number of manufacturers supply proprietary window systems with their workstations. Sun Microsystems supply two products with their workstations - Sunview and OpenWindows. DEC have a product called DECWindows which is available on DEC's Unix and VMS workstations.

Compatibility Both DECWindows and OpenWindows are X- compatible. They both operate on the client-server principle, and in general it is possible to run standard X clients under a DECWindows or OpenWindows server. There are, however, problems, in that the different servers may adopt different font-naming schemes, and both DECWindows and OpenWindows may utilise extensions to the standard X protocol.

The Main Components of X Any X window system consists of 2 distinct parts – the X server and 1 or more X clients.

Server and Client(s) It is important to realize the distinction between the server and the client. The server controls the display directly, and is responsible for all input/output via the keyboard, mouse or display. The clients, on the other hand, do not access the screen directly - they communicate with the server, which handles all input and output. It is the clients which do the "real" computing work - running applications or whatever. The clients communicate with the server, causing the server to open one or more windows to handle input and output for that client.

The X server When using X on a workstation, the first task which must be done after logging in is to start up the X server. This is generally accomplished by using a script called xinit. This, like most other X-related code, usually resides in the directory /usr/bin/X11.

Starting the server in this way, however, is generally not a good idea, as it simply starts up the server, and does not give the opportunity to start any clients. Indeed, as the server controls all input and output, and there are no clients communicating with the server, it is not immediately obvious how to start up a client!

startx command Start the X server Check to see if the user has a personal X startup command file, named ~/.xinitrc. If this file does exist, the commands contained within it will be executed. If it does not exist, a simple default startup configuration, which can be found in /usr/lib/X11/xinit/xinitrc, will be used.

X clients The main means of communication with X is by using the keyboard and the mouse. The mouse moves a pointer round the screen. Pressing the mouse buttons activates various functions depending on where the mouse is located. To send your input from the keyboard to any particular client, you must position your mouse pointer over that client.

The xterm client The xterm client is probably the most commonly used X clients. It simply provides a terminal window to the machine on which the xterm client is running. For example, if the xterm is running on a Sun, a normal Unix shell will appear within the Xterm window.

The xman client

xman is another very useful client. It is a graphical interface to the Unix manual pages. By using the mouse, it is possible to display any of the hundreds of pages of information available. It is one of the most useful of all the X clients - learn how to use it!

The xedit client xedit is a simple text editor. It does not have the power of editors such as vi or emacs, but in some circumstances this is a distinct advantage, as it means that there are very few commands to remember. This makes it a very easy editor to use.

The xbiff client

xbiff client The strangely named xbiff client notifies you when new mail arrives. It produces a picture of an American-style mailbox, and whenever new mail arrives, the flag on the side of the box will be raised.

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Why it is called biff? A useless piece of trivia: xbiff is so called because the original Unix utility to notify the user of new mail was called biff. Biff was a dog, owned by a student at University of California, Berkeley in the days when BSD Unix was being developed. Biff had a habit of barking when the postman came

The xclock client. xclock displays an analogue clock on your screen.

The Window Manager The window manager is a rather special X client. It is a tool which allows you to move, resize, iconify and kill other windows. It provides a title bar for every window, and may make several pop-up menus available.

Window Managers for X FVWM FVWM95 TWM/VTWM MWM CTWM OLWM/OLVWM wm2/wmx AfterStep AmiWM Enlightenment WindowMaker SCWM IceWM Sawfish Blackbox Fluxbox Metacity Others...

Partial list of features new to 2.5.x Full Enhanced Window Manager Hints support Full internationalization Greatly improved font support, including anti-aliasing Improved decoration code (no flickering anymore) Featuring side titles, including vertical text Powerful WindowShade in all directions, including diagonal Supporting PNG including alpha blending Image rendering in colorsets Perl library for creating modules in Perl New module FvwmPerl to enable scripting in rc files Optional text shadows (looks nice with light text)

Desktops GNOME KDE CDE XFce

KDE KDE is a modern network transparent desktop environment which uses the Qt cross-platform GUI toolkit. It contains a base set of applications such as a window manager (called kwm), web browser, instant messenger, and integrated help system, all with a consistent look and feel, and translations for over 50 languages.

The GNU Network Object Model Environment The GNOME (pronounced "Gah-NOME") project's aim is to build a complete, user- friendly desktop based entirely on free software. It is not a window manager, and in fact has to be run in conjunction with a window manager. GNOME has advanced rapidly and is now very popular, particularly on the Linux platform.

CDE-The Common Desktop Environment The Common Desktop Environment (CDE) is a commercial graphical user interface for UNIX in its various flavors (AIX, Digital UNIX, HP/UX, Solaris, UnixWare, etc.). The desktop has been jointly developed by Hewlett-Packard, IBM, Novell and Sun Microsystems. It has been adopted as a standard operating environment by these companies and many others in the UNIX workstation market.

History of Linux (Courtesy Prof. Remzi H. Arpaci-Dusseau)

Linux Features Multi-tasking (more than one task/program can run simultaneously). Multi-user (more than one user can work simultaneously). Multi-processing (more than one processor is supported by the OS, SMP support is very stable). POSIX compliant…….behavior similar to traditional Unixes (look and feel). Runs on a variety of architectures (not just ix86 based PCs): Sparc, Alpha, PowerPC, MIPS, PalmPilot,... An Embedded version of Linux exists for hand- held devices and real-time OS applications.

Interfacing Linux with Other OS Wine and WABI are windows emulators for Linux (limited success so far). Wine is GPL, WABI is commercial. DOSemu is a very stable MS-DOS emulator.Some of your partitions on your disk can be MS-DOS partitions. You can read MS-DOS floppies too. VMware is the best alternative, if you need to run both Linux and MS Windows. It is a commercial emulator that emulates the x86 hardware flawlessly, so any OS that can run on the x86 platform can be installed under VMware as a separate application!VMware

Interfacing Linux with Other OS VMWare: Windows XP under Linux