Witch - Welcome to the world of W. i. t. c. h.
i3 - A dynamic tiling window manager designed for X11, inspired by wmii, and written in C.
Hyperswitch - HyperSwitch provides a compelling alternative to HyperDock for keyboard junkies. What's New
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.
Contexts - Switch between application windows effortlessly — with Fast Search, a better Command-Tab, a Sidebar or even a quick gesture. Free trial available.
Xmonad - xmonad is a dynamically tiling X11 window manager that is written and configured in Haskell.