i3 - A dynamic tiling window manager designed for X11, inspired by wmii, and written in C.
Compiz - Project information. Maintainer: PS Project Management Team. Driver: Compiz Maintainers. Licence: GNU GPL v2, GNU LGPL v2. 1, MIT / X / Expat Licence.
awesome - A dynamic window manager for the X Window System developed in the C and Lua programming languages.
Witch - Welcome to the world of W. i. t. c. h.
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.
Dexpot - If you don't have Dexpot yet, the new update makes it a must-have tool for Windows, adding a ton of features to your desktop that you never knew you wanted.