Does Gnome Shell use Mutter? In Wikipedia is written that Gnome Shell in Gnome 3 uses Mutter window manager. But `ps x | grep mutter` shows that Mutter is not running. Moreover I had experience with working Gnome Shell _before_ I installed Mutter. Does Gnome Shell really use Mutter? Which WM are used and which can be used with Gnome Shell?

Yes, `mutter` is used by `gnome-shell` but it's used as a library. The `mutter` binary is just a tiny program that links against `libmutter`. You could try like this:


lsof | grep mutter