window manager
operating system software
window decoration
graphical user interface elements drawn around a program's window by the window manager (title bar, window border, etc.)
Mutter
GNOME window manager and display server
Ardent Window Manager
early window manager for the X Window System
Dynamic window manager
tiling window manager with preset layouts
Sawfish
window manager for Linux and other Unix
Enlightenment
window manager for Unix-like operating systems
X window manager
software for Unix type operating systems
stacking window manager
window manager that draws all windows in a specific order, allowing them to overlap, using a technique called painter's algorithm
Window Maker
X11 window manager originally designed to provide integration support for the GNUstep Desktop Environment
compositing manager
type of window manager
tiling window manager
window manager with an organization of the screen into mutually non-overlapping frames