1. What is X11? X WINDOW System Version 11, referred to as X11, is a graphic display system for a transparent client / server architecture. It supports the application to draw pixels, lines, texts, images, etc. on your screen. X11 also includes some other auxiliary library such that it can easily draw user interfaces, such as buttons, text input areas, and more. X11 is a UNIX factatic graphics system standard. Linux, a variety of BSD versions and most commercial Unix use it. Desktop environments such as CDE, KDE and GNOME are running on it. 2. What is Xfree86? XFree86 is an implementation of an open source for X11. Initially, it developed on Intel X86 PC, so named. Now it can run on major hardware architectures and operating systems, including OS / 2, Darwin, Mac OS X, and Windows. 3. What is the window manager? In most graphics environments, the appearance of the window border (title bar, shutdown button, etc.) is defined by the system. The X11 is not the case. In X11, the window of the window (also known as "decorative") is provided by a separate program called window manager. It is generally believed that the window manager is only another customer program; it is launched with a usual approach and communicates with the X server in the same way. We choose from a lot of different window manager. Xwinman.org has a detailed list. Most common window managers allow users to customize the appearance of the window. Many Window Manager also offers additional features, like a pop-up menu, Docks, or Program start button on the root window. 4. What is GNOME and KDE? They are all desktop environments, and there are many similar environments. Their use is to provide additional frames to the app, making their appearance, sensation, and behavior are consistent. For example: Graphics Engine: X11 Window Manager: Sawfish Desktop: The boundary between the GNOME graphic display engine, window manager, and desktop is blurred, because some similar or identical features will be implemented by one or more of them . This is why a particular window manager may not be used by another specific desktop environment. Many procedures are developed for a specific desktop environment. Most programs can operate without loss or limited loss after the function library of the corresponding desktop environment (as well as the corresponding lower-level function library). The example is that more and more GNOME programs can be installed and run without running GNOME. Unfortunately, there is no similar progress to the KDE app.
