bspwm - A tiling window manager based on binary space partitioning
i3 - A dynamic tiling window manager designed for X11, inspired by wmii, and written in C.
Ratpoison - Ratpoison is a simple window manager with no fat library dependencies, no fancy graphics, no window...
Fluxbox - Fluxbox is a window manager for X that was based on the Blackbox 0.61.1 code.
Openbox - Openbox is a highly configurable, next generation window manager with extensive standards support.
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.