i3 - A dynamic tiling window manager designed for X11, inspired by wmii, and written in C.
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.
Xmonad - xmonad is a dynamically tiling X11 window manager that is written and configured in Haskell.
Openbox - Openbox is a highly configurable, next generation window manager with extensive standards support.
qtile - Qtile is a full-featured, hackable tiling window manager written in Python.
bspwm - A tiling window manager based on binary space partitioning