HyperKeys - Unleash the power of your keyboard by letting you bind ANY action to a shortcut. It's open-source and fully extendable. You can code you own actions or use one from the community !
VistaSwitcher - VistaSwitcher is an elegant and powerful task management utility for Windows OS.
Skippy-XD - Skippy-XD is a full-screen task-switcher for X11.
Easy Window Switcher - Easy Window Switcher brings the convenience of Mac's easy window switching to Windows
picom - A lightweight compositor for X11 (previously a compton fork).
SwitchBlade - Find and activate windows without leaving the keyboard. Faster than alt-tab.