I use KDE. Some use GNOME. Most other options are probably to be left out as X11 is unsafe.
Cosmic is not nearly finished, but will probably be a bit safer, as its in rust, even though not tested.
Then there are window managers like Sway, Hyprland, waymonad, wayfire, etc.
RaspberryPi also has their own Wayland Desktop.
Is every Wayland Desktop / WM equally safe, what are other variables here like language, features, control over permissions, etc?
IF by “security” one means bugs have been prevented from living in it, there is one coded in Haskell, it may be named XMonad or something…
( … digging … )
Yep:
https://en.m.wikipedia.org/wiki/Xmonad
from there:
“Due to the small number of lines of code of the Xmonad application, the use of the purely functional programming language Haskell, and recorded use of a rigorous testing procedure it is sometimes used as a baseline application in other research projects. This has included re-implementation of xmonad using the Coq proof assistant,[31] a determination xmonad is an imperative program,[32] and studies of package management relating to the NixOS linux distribution.[33]”
Dig: 2000-ish lines of code.
https://xmonad.org/
https://xmonad.org/documentation.html