plwm: X11 window manager written in Prolog

plwm is a highly customizable X11 dynamic tiling window manager written in Prolog.

Main goals of the project are: high code & documentation quality; powerful yet easy customization; covering most common needs of tiling WM users; and to stay small, easy to use and hack on.
↫ plwm GitHub page

Tiling window managers are a dime-a-dozen, but the ones using a unique or uncommon programming language do tend to stand out.