Desktop Environments

Desktop Environments

What is X Windows?

X Window System is a networking and display protocol which provides windowing on bitmap displays. It provides the standard toolkit and protocol to build graphical user interfaces (GUIs) on *NIX operating systems and OpenVMS, and is supported by almost all other modern operating systems.

Desktop Managers for Linux

Part of what makes Linux useful on your computer is its graphical user interface. The GUI gives Linux a "look and feel" with clickable icons and widgets, as well as screen borders, scroll bars, and menus that the user can manipulate and customize.

This "point and click" environment makes the operating system more intuitive by presenting interface options in an attractive visual layout that doesn't require knowledge of textual commands. Without the GUI, Linux (or any operating system) requires users to type commands in a procedure that is known as the Command Line Interface (CLI).

What is a Desktop Manager?

In graphical computing, a desktop environment (DE, sometimes desktop manager) offers a graphical user interface (GUI) to the computer. The name is derived from the desktop metaphor used by most of these interfaces, as opposed to the earlier, textual command line interfaces (CLI). A DE typically provides icons, windows, toolbars, folders, wallpapers, and abilities like drag and drop. As a whole, the particularities of design and function of a desktop environment endow it with a distinctive look and feel.

Elements of Desktop Environment

A desktop environment is made of several parts, such as :

1. Window Manager 2. File Manager 3. Application programs(optional)

1. Window Manager

The most fundamental part of a DE is the window manager or WM. A window manager creates a certain way for application windows to present themselves to the user. It manages the various application windows, keeping track of which ones are open and providing features to switch between them.

2. File Manager

This application manages files/ folders and presents them in a way that the user finds convenient. It provides some basic file operations like viewing, copying/ moving to different locations and deleting. DEs usually provide a way to set wallpapers and screensavers, display icons on the desktop, and perform some administrative tasks.

3. Application Programs

Desktop Environments may optionally include application programs such as word processors, CD/DVD writing applications, web browsers and e-mail clients. Some exceptions must be noted here. Window managers like Fluxbox, wmii and Ratpoison are capable of operating independently of a desktop environment and were written with this objective in mind.

Additional hand-picked applications add functionality and hence render them capable of operating as a full-blown DE. For this reason, they are considered to be lightweight desktop environments. This contrasts the behaviour of WMs like Metacity and KWin which were not written with the objective of operating independently of a DE.

Desktop Environments   Gnome Desktop Environment   GNOME (GNU Network Object Model Environment) is an international effort to build a complete desktop environment—the graphical user interface which sits on top of a computer operating system—entirely from free software.   This goal includes creating software development frameworks, selecting application software for the desktop, and working on the programs which manage application launching, file handling, and window and task management.   What is Gnome?   The GNOME project provides two things: The GNOME desktop environment, an intuitive and attractive desktop for users, and the GNOME development platform, an extensive framework for building applications that integrate into the rest of the desktop.   Is that all about Gnome?   Surely, no, in fact GNOME is a desktop software project, but it's large enough to mean different things to different people. If you're a software user, it's a desktop and some applications. If you're a software developer, it's a platform, toolkit, and community.   The core applications consist of the Nautilus file manager, the panel and its associated gadgets called panel applets, the usual complement of accessories (text editor, terminal emulator, calculator, and so on), a few games, and some larger applications like the Evolution mail, calendar, and address book, the Gnucash finance tool, the Rhythmbox music player, and the Totem video player.   The Gnome Desktop Environment is made of two main components:   1. Gnome Desktop and Applications 2. Gnome Development Environment   1. GNOME Desktop and Applications   The desktop itself and its menus are designed to look familiar to anyone who has ever used a computer. If you know how to use a mouse, you can probably find your way around a menu labeled "Programs" or "System." Those menus are part of the default setup for the GNOME panel, that grey bar at the top or bottom of the screen.   In addition to the menus and a few application launchers (or, as people sometimes call them, buttons), you'll find tiny applications called applets that run in the panel. The clock is included by default, as is a list of currently open windows. To add more applets, right-click on a blank spot in the panel and select one of the items under Add to Panel. Some of the options are:   Workspace Switcher: GNOME lets you have multiple workspaces, as though you had several monitors at once. To switch from one to another, click on the workspace you want. You can also move windows from one workspace to the next by dragging their icons in the workspace switcher. Right-click the applet to adjust the number of workspaces and display options.   Battery Monitor: Does exactly what it says on the tin. Right-click the applet for options, or to suspend your system to disk.   Character Palette: Don't have an international keyboard? Click one of the letters in the character palette, then paste or middle-click where you want it to go. Mine has á é í ó ú ñ and €, but you can select from dozens, or create your own.   The file manager seems basic enough: click a folder and it opens to display the contents; click a file and the relevant application starts and displays the file. But click around a little, and you'll notice a few quirks. By default, the file manager works in "spatial" mode, similar to some editions of the Macintosh Finder, where each window represents a folder.   Click a folder inside a window, and a new window opens up. Click the same folder again, and the original window will come to the front. If you want to change that behavior, right-click a folder and select Explore to get a Windows Explorer style file manager.   2. The GNOME Development Platform   The GNOME development platform is used for more than just GNOME applications. It offers independent developers a number of attractions:   Languages: GNOME libraries are mostly written in C, but they're almost universally wrapped for access by other languages. GNOME developers write in C++, Python, C#, Perl, Java, and more. Applications like Novell iFolder and the F-Spot camera tool are written in C# using the GTK+ and GNOME libraries.   They do this by using the gtk-sharp and gnome-sharp wrapper libraries. Efficient low-level code and a fast C# runtime mean that they run quickly despite offering the conveniences of C# and the full GNOME toolkit to their developers.   Developer Tools:   The Glade user interface designer lets developers lay out user interfaces, which it saves as XML files accessible to applications making use of the libglade library--no more describing windows in dry code when you can draw them.   IDEs like Monodevelop can even read the interface definition files and create dummy functions that you fill out, cutting out the boring part of development. Future developer tools include a new UI design tool built entirely in C# called Stetic.   Systems and Standards:   Developers have access to the system tray through the GNOME notification area, and desktop-wide messaging systems through dbus. Both are described on freedesktop.org, a website dedicated to development of free software desktop applications and tools.   Developers following FreeDesktop.Org standards know that their applications will work equally well in KDE and GNOME, and that they are providing applications that will age gracefully and provide users with a coherent, consistent, and pleasant desktop software experience.         Desktop Environments   K Desktop Environment   What is KDE?   KDE is a desktop environment. In other words, KDE is a collection of programs, technologies and documentation that attempt to make life easier for computer users. KDE is targeted at UNIX® workstations. It features network transparency and a contemporary work philosophy.   The creators of the K Desktop Environment are a world-wide group of software engineers. This group's major goal in free software development is to provide high quality software that empowers the user with easy control of his computer's resources.   KDE seeks to fill the need for an easy to use desktop for UNIX® workstations, similar to the desktop environments found under Mac® OS or Windows® 95/NT. KDE meets the requirement of users for an easy to use work environment. Tools used to reach this end are: enhanced inter-application communication, component reuse, generalized drag and drop, uniform look and feel and many more. Thus, KDE offers much more than the traditional UNIX® window managers.   The K Desktop Environment is made of following components:     Desktop Environment   In combination with a free implementation of UNIX®, KDE provides to the world an open and completely free desktop computing platform either at home or at work. This platform is available to anyone free of charge including its source code for anyone to modify.   While there will always be room for improvement we believe we have now delivered a viable alternative to some of the more commonly found and commercial operating systems/desktops combinations available today. It is our hope that the combination of UNIX® and KDE will finally bring the same open, reliable, stable, and monopoly free computing to the average computer user that scientists and computing professionals world-wide have enjoyed for years.   Application Development Framework   KDE focuses on the user's needs, but it's obvious that this focus is more easily achieved by also giving developers the best tools. KDE code contains, and comes with, some of the best development technologies of the modern computing age.   Authoring applications under UNIX®/X11 used to be an extremely tedious and labor intensive process. KDE recognizes the fact that a computing platform is only as good as the number of first class applications available to the users of that particular platform.   KDE defines new technologies in DCOP and KParts, created to offer a component document model and technology. Together with the complete KDE libraries programming interface, DCOP/KParts are set in direct competition with other similar technologies like Microsoft® MFC/COM/ActiveX technologies. The excellent quality and the high level of refinement of KDE's application programming interface (API) enables developers to focus on original and interesting issues and avoid reinventing the wheel.   KDE Application Suite   In its current form, KDE provides, apart from the essential desktop component applications, a suite of powerful office programs known to the world by the name KOffice.   KOffice is based on the KDE DCOP/KParts technologies. It currently contains: a word processor with desktop publishing capabilities (KWord), a spreadsheet application (KSpread) and accompanying charting program (KChart), a presentation program (KPresenter) and a vector drawing program (Kontour).   Tying things together is the KOffice Workspace, an integrated shell to ease the use of the KOffice components in conjunction with each other. Additional components include an email client, a news reader, and a powerful PIM (Personal Information Manager - an organizer).         Desktop Environments   Other Desktop Environments   Both Gnome and KDE are full flagged Desktop Environment for *Nix systems. Apart from these two there are a lot of other Desktop Environments & Windows Manager that are used with different type of *Nix System, most notable among is Xfce. Xfce is a very lightweight DE and popular too.   Here we will discuss some of them:   Xfce(Complete DE)     Xfce is a lightweight desktop environment for UNIX platforms. It is similar to the commercial CDE, and is now based on the GTK+ toolkit.   A strong point of Xfce is its ease of configuration - it is driven entirely by the mouse. The latest version features drag and drop, session management, translations for numerous languages, including support for multi-byte character sets, and numerous other features.     The desktop environment includes a window manager, called XFwm, the main panel, a file manager, a backdrop manager, a sound manager, a calendar, a pager module, and a GNOME compliance module.   CDE (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.   The CDE incorporates the dtwm window manager. This is a Motif-compliant, virtual window manager and is similar to the HP/UX program vue.   Other Desktop Environments   * EDE:  The Equinox Desktop Environment is small desktop environment built to be simple and fast. It is based on a modified FLTK library.   * FVWM-Crystal:  A desktop environment built around the FVWM window manager, ROX-Filer file manager, and others.   * Athene Desktop:  A commerical desktop with its own graphics server, although it can also display X11 applications for compatibility. A free download edition is available.   * Metisse: An experimental X desktop which uses a virtual X server, a special version of Fvwm, and OpenGL support to implement various window effects, including rotation, scaling, and blending.   * JD4X:  The Java Desktop for X aims to provide a Java based desktop that can run both Java and native applications. It is initially only availabe for Linux x86 platforms.   * 3D-Desktop:  An OpenGL program for switching virtual desktops in a seamless 3-dimensional manner on Linux.   * XD640:  A simple graphical desktop environment for X designed for small screens and slow processors. * XPde:  A Windows XP-like desktop environment designed for Windows users migrating to Linux.   * ROX:  An attempt to bring some of the good features from RISC OS to Unix and Linux. It includes a desktop environment based around a file manager.   * Flowe Desktop: A commerical desktop environment for Linux. This has now been bought by SlickEdit Inc, although no release is currently available.   * 5dwm:  The Indigo Magic Desktop for Linux.   * foXdesktop:  An attempt to create a new desktop environment based on FOX (an LGPL widget set). It is currently in an early state of development.   * UDE:  Unix Desktop Environment - early stages of a new window manager written using only XLib, rather than special GUI libraries.   * EDE: the Equinox Desktop Environment. This is the beginnings of a small, fast, low memory environment, based on the Fast Light Toolkit. * The GREAT Desktop, free for Linux (statically linked with Motif).