https://github.com/koekeishiya/yabai
koekeishiya@ continues his tradition of rewriting window managers for OSX. This one is an evolution of chunkwm. It's faster and better in various ways. Controlled by the keybinds in skhd.
On non-SIP machines, you need to run sudo _ yabai --install-sa && sudo yabai --load-sa
or set up the auto load: https://github.com/koekeishiya/yabai/wiki/Installing-yabai-(latest-release)#macos-big-sur---automatically-load-scripting-addition-on-startup