This book orients the new user to window system concepts and provides detailed tutorials for many client programs including the xterm terminal emulator and the mvm window manager. Once you have a basic knowledge of the system, the later chapters explain how to customize the X environment and provide sample configurations.
This section describes how to install three popular desktop environments on a FreeBSD system.A desktop environment can range from a simple window manager to a complete suite of desktop applications.Over a hundred desktop environments are available in the x11-wm category of the Ports Collection.
X Window System User's Guide (X Window System Series)
While it is common to associate X with Unix, X servers also exist natively within other graphical environments. VMS Software Inc.'s OpenVMS operating system includes a version of X with Common Desktop Environment (CDE), known as DECwindows, as its standard desktop environment. Apple originally ported X to macOS in the form of X11.app, but that has been deprecated in favor of the XQuartz implementation. Third-party servers under Apple's older operating systems in the 1990s, System 7, and Mac OS 8 and 9, included Apple's MacX and White Pine Software's eXodus.
When an operating system with a native windowing system hosts X in addition, the X system can either use its own normal desktop in a separate host window or it can run rootless, meaning the X desktop is hidden and the host windowing environment manages the geometry and appearance of the hosted X windows within the host screen.
Carnegie Mellon University produced a remote-access application called Alto Terminal, that displayed overlapping windows on the Xerox Alto, and made remote hosts (typically DEC VAX systems running Unix) responsible for handling window-exposure events and refreshing window contents as necessary.
X derives its name as a successor to a pre-1983 window system called W (the letter preceding X in the English alphabet). W ran under the V operating system. W used a network protocol supporting terminal and graphics windows, the server maintaining display lists.
The original idea of X emerged at MIT in 1984 as a collaboration between Jim Gettys (of Project Athena) and Bob Scheifler (of the MIT Laboratory for Computer Science). Scheifler needed a usable display environment for debugging the Argus system. Project Athena (a joint project between DEC, MIT and IBM to provide easy access to computing resources for all students) needed a platform-independent graphics system to link together its heterogeneous multiple-vendor systems; the window system then under development in Carnegie Mellon University's Andrew Project did not make licenses available, and no alternatives existed.
The project solved this by creating a protocol that could both run local applications and call on remote resources. In mid-1983 an initial port of W to Unix ran at one-fifth of its speed under V; in May 1984, Scheifler replaced the synchronous protocol of W with an asynchronous protocol and the display lists with immediate mode graphics to make X version 1. X became the first windowing system environment to offer true hardware independence and vendor independence.
Scheifler, Gettys and Ron Newman set to work and X progressed rapidly. They released Version 6 in January 1985. DEC, then preparing to release its first Ultrix workstation, judged X the only windowing system likely to become available in time. DEC engineers ported X6 to DEC's QVSS display on MicroVAX.
While X11 had received extensions such as OpenGL support during the 1990s, its architecture had remained fundamentally unchanged during the decade. In the early part of the 2000s, however, it was overhauled to resolve a number of problems that had surfaced over the years, including a "flawed" font architecture, a 2D graphics system "which had always been intended to be augmented and/or replaced", and latency issues.[52]X11R6.8 came out in September 2004. It added significant new features, including preliminary support for translucent windows and other sophisticated visual effects, screen magnifiers and thumbnailers, and facilities to integrate with 3D immersive display systems such as Sun's Project Looking Glass and the Croquet project. External applications called compositing window managers provide policy for the visual appearance.
The X window system (and its popular implementation X.org) is amazing and complex too - client server model, forwarding the display to other systems, support for wide array of devices, primitive drawing functions. Moreover, the many ways to configure.
The Solaris X server, XSun, is composed of the X Consortium's X11R6 sample server with the Display PostScript (DPS) imaging system extension, additional X Consortium X extensions, and Sun added value. The Solaris X server is the foundation for the Common Desktop Environment (CDE) and underlies the CDE desktop. The server handles communication between client applications, the display hardware, and input devices. By default, the Solaris X server runs with the CDE dtlogin and window manager (dtwm), but any X Window System manager that is ICCCM (Inter-Client Communication Conventions Manual) compliant runs with the server. Software developers can write applications for the Solaris environment using the Xlib library or a variety of toolkits, includingthe Motif toolkit and the Xt toolkit.
Most of us connect to the CTM server via a PC running Windows, essentially making the PC a terminal. The PC interacts with the server through the X-windows system, forwarding the display from the server to the PC. Software must be installed on the PC to make this link work and the best software (so far) for this task is the PuTTy terminal emulator and the Xming X-window client.
The most important setting is the X11 Forwarding. Without that set, the X-window system cannot find your PC for display. Save the configuration by typing a name (i.e. CTM) in the box under 'Saved Sessions' on the Sessions screen. Press the Save button to save the configuration. Click Open to open the terminal window or Cancel to close PuTTy. The next time PuTTy is run, the session named CTM will be shown. Select CTM with the mouse and click Open to launch.
As mentioned at the beginning, network transparency is one of the central characteristics of a Unix system. X, the windowing system of Unix operating systems, can use this feature in an impressive way. With X, it is no problem to log in to a remote host and start a graphical program that is then sent over the network to be displayed on your computer.
In the case of cookie-based access control, a character string is generated that is only known to the X server and to the legitimate user, like an ID card of some kind. This cookie is stored on login in the file .Xauthority in the user's home directory and is available to any X client wanting to use the X server to display a window. The file .Xauthority can be examined by the user with the tool xauth. If you rename .Xauthority, or if you delete the file from your home directory by accident, you will not be able to open any new windows or X clients.
This variable holds the value of window-system used for thefirst frame created by Emacs during startup. (When Emacs is invokedas a daemon, it does not create any initialframes, so initial-window-system is nil, except onMS-Windows, where it is still w32. See daemon in The GNU Emacs Manual.)
This function returns a symbol whose name tells what window system isused for displaying frame (which defaults to the currentlyselected frame). The list of possible symbols it returns is the sameone documented for the variable window-system above.
Do not use window-system andinitial-window-system as predicates or boolean flag variables,if you want to write code that works differently on text terminals andgraphic displays. That is because window-system is not a goodindicator of Emacs capabilities on a given display type. Instead, usedisplay-graphic-p or any of the other display-*-ppredicates described in Display Feature Testing. 2ff7e9595c
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