is it possible on a mac to quicky see the desktop along with the last active window?
Simplest is in the Dock - 

Hold  Alt ⌥  &amp; Right Click > Hide Others



Alternatively &amp; probably better than my original answer [I don't know if this is system-wide, but it does appear in all the apps I checked, Apple &amp; 3rd party]
 Cmd ⌘   Opt ⌥   H  is the key command to Hide Others