1. GNOME, KDE and X Windows

2. The GNOME Project was started in 1997 to produce a free (as in freedom) desktop environment. GNU Network Object Model Environment. It is a Graphical User Interface. GNOME allows the user to select one of several desktop appearances.

3. it is the most popular desktop environment for GNU/Linux. GNOME includes a set of the same type of applications found in the Windows Office 97 product: a word processor, a spreadsheet program, a database manager, a presentation developer, a Web browser, and an e-mail program.

4. GNOME exists because of its participants. Over 3500 people have contributed changes to the project's code repositories, including the employees of 106 companies. GNOME software is available in a large number of spoken languages, and the project aims to ensure that its software is usable for everyone, including people with disabilities.

5. KDE K Desktop Environment (KDE) is an Open Source graphical desktop environment. KDE has a complete graphical user interface (GUI) and includes a file manager, a window manager, a help system, a configuration system, tools and utilities, and several applications. The most popular suite of KDE applications is KOffice, which includes a word processor, a spreadsheet application, a presentation application

6. X Windows The X Window System was the result of research efforts in the early 1980s at Stanford University and MIT, aided by IBM. The X Window System (sometimes referred to as "X" or as "XWindows") is an open, cross- platform, client/server system for managing a windowed graphical user interface in a distributed network.

7. X is hardware-independent. With X you can run Microsoft Windows Applications on a UNIX workstation, or you can run a UNIX application on an Apple Macintosh system.