i3 - A dynamic tiling window manager designed for X11, inspired by wmii, and written in C.
Fluxbox - Fluxbox is a window manager for X that was based on the Blackbox 0.61.1 code.
dwm - dwm is a dynamic window manager for X. It manages windows in tiled, monocle and floating layouts. All of the layouts can be applied dynamically, optimising the environment for the application in use and the task performed.
Openbox - Openbox is a highly configurable, next generation window manager with extensive standards support.
Xmonad - xmonad is a dynamically tiling X11 window manager that is written and configured in Haskell.
Compiz - Project information. Maintainer: PS Project Management Team. Driver: Compiz Maintainers. Licence: GNU GPL v2, GNU LGPL v2. 1, MIT / X / Expat Licence.