On X Window System

Graphical (GUI) shells about body on top of a windowing system. In case of the X Window System, there are both absolute X window managers, and complete desktop environments which depend on a window manager.

X Window Arrangement environments (mainly for Unix-like operating systems):

absolute X window managers, such as:

Blackbox

Fluxbox

ratpoison

xmonad

dwm

desktop shells, such as:

Enlightenment DR17

Cinnamon

Unity

abounding desktop environments, such as:

CDE

GNOME

KDE

Xfce

LXDE

On added platforms

Amiga environments:

Ambient (for MorphOS)

Directory Opus

ScalOS

Wanderer (for AROS)

Workbench

DOS Shell

Finder (for Mac OS X)

Doors CS, MirageOS, Ion, and CrunchyOS (for TI-83 and TI-84 alternation graphing calculators)

OS/2 environments:

Presentation Administrator (for OS/2 1.1 and greater and eComStation)

Workplace Shell (for OS/2 2.0 and greater and eComStation)