LinuxBBQ

Simple, swm like window manager without borders and window decoration, with builtin wmutils-like tool, grid-based layout, and simple config.

https://github.com/vixus0/tartwm

^ So essentially it's rule sets that can adapt to any WM or even a DE, am I right? Or am I confused? Is this technically a WM, since you can add it on top of another WM? Maybe it is just to early for me, I will read it again later. Sorry.

Short answer: It's a WM, but it can be used to interop/co-exist with other de/wm as well.

^ Thanks, I think I will try it on top of Mate :)

the readme says:
A grid-based floating window utility with collision detection and tags.

After enjoying the pleasures of other, more full-featured window managers for some time (eg. openbox), I've realised it would be more useful to have tartwm able to run alongside such a window manager. The more powerful WM can then handle pesky things like mouse focus and window decoration.

To this end, TartWM can be considered a simple but powerful tool for window arrangement. TartWM is not a static/dynamic tiler in the traditional sense.

^ you might like wmutils, then.