NELUG meeting 15/3/2000
Horst Kausch
v0.1 2000-03-15

Overview

The desktop/graphical user interface experienced by the user consists of several layers.

X Window system

• client/server architecture
• the server delivers input events to clients and displays the output
• the client is the application calling on the server to do the input/output processing
• network transparent
• X-lib library provides low-level manipulation of graphics

Window Managers

• provides window management functions:
  • focus – which client gets input events
  • create/destroy windows
  • move windows
  • resize windows
  • stacking – raise/lower windows
• provides window decorations as visual clues of window status and functions:
  • title bar
  • borders
  • buttons for window operations
  • window menu
  • highlighting of window with focus

Widget Sets

• toolkits implementing the abstract objects of the user interface:
  • check buttons
  • radio buttons
  • text entry fields
  • scroll bars
  • scroll lists
  • tabbed dialogs
• provides look and feel of the user interface (X-tended Graphical Environment)

Desktop Environment

• panel for starting programs, displaying task list, monitors, etc.
• desktop – object can be dragged onto desktop for quick access
• consistent look and feel
• standardized menu and toolbars, keybindings, color-schemes, etc.
• internationalization
• centralized consisted dialog driven desktop configuration
• themeable
• integrated help system
• complete network transparency
• component architecture
• object oriented inter-program communications mechanism through CORBA or DCOM
• Document Object Model (DOM) using XML file formats
• suite of applications

Only KDE and Gnome (will) implement all of these features.

Advanced Feature Comparison

Typical configurations

Screenshots

Plain X desktop with only an xterm and no window manager

Plain X desktop with twm managing an xterm

AnotherLevel desktop (RedHat 5.* default)

KDE-1.1 desktop

Gnome 1.0 desktop