I used Window Maker for years - still have it installed as the desktop of choice on older machines. It's fast, simple, reliable and direct.
Yes and it makes for a great UI on a VNC server on a Raspberry Pi running as a SSH box, for example. Lightweight.
I switched to i3 a couple of years ago but I've used WindowMaker the longest of any window manager in my 25 years of Unix usage.
(Funnily, my current Xfce setup still visually resembles my OpenStep-like setup of that time.)