Looks like the built-in window organizing thing Win11 comes with. When you drag a window to the top edge a little menu pops open for tiling your open windows.
Doesn't work with every window though, but browsers and spotify can be arranged that way.
There is GlazeWM (simlar to i3 - the only one that works properly on my win11 spyware), I use it daily for work (company laptop).
These are also:
Komorebi (too buggy for me)
Workspacer (like dwm) - used to crash alot before
bug.n (dwm fork with the bar and same congih in ahk) - dead nowdays