Basic question about Linux versions - 3D Linux

Probably this has been asked an infinite number of times before
in this usenet group but I do not have an infinite number of times
to surf through an infinite number of posts.
A long time ago the Graphical User Interface came into existence
and this was early on placed upon text operating systems (like
CP/M) often to control program input from storage devices.
(DOS and Windows are examples but there were others.)
People see upon generally two dimensional retinas but it
is often seeing in a three dimensional space.
A lot of operating systems have two dimensional objects
that can be 'on top' or behind other two dimensional
screen spaces, but they are not quite three dimensional
in a virtual 3D space.  The most I can think of at the
moment is how once upon a time one could 'wave a paper'
around slightly on open SUSE a while back, and that
was mostly another 2D image.
Now Windows is only one OS that is generally with
stifled innovation because it does not have a 'free
and open source' license.  Linux however is not
crippled and stifled in that way.  What add ons and
operating systems now exist with 3 dimensional
space as its GUI rather than a 2D one (like most
GUIs)?