What is "plwm"

In Unix computing, PLWM (The Pointless Window Manager) is a Python package, containing classes suitable for implementing an X window manager, and also a window manager created using the PLWM package. Its internal structure is highly modularized, and can be fully customized and scripted with configuration files written in the implementation language, in a manner similar to Emacs, in order to change everything from keybindings to window management policies.

PLWM is one of a very few modern window managers that is not reparenting.