This tool allows certain configurable actions to be taken upon events from `evdev` devices.
These actions include feeding a new event back into a device (useful for button remapping) and running an arbitrary command.
This tool **cannot** prevent the original event from being processed by other userspace programs listening for `evdev` events, for example ones using `libinput`.
It was originally created because there currently is no way to give extra mouse buttons functionality when using Mutter.