> xmacbsd as far as i can see, is the same as x under most versions of x,

Exactly.  It's the X server.  It doesn't control X's look and feel much
at all, though.  It's meant to provide the clients (window managers,
xterms, xclocks, etc.) with a means to recieve input (keyboard/mouse/etc)
and send output (drawing, etc.).

-allen

-- 
              Allen Briggs - end killing - briggs@macbsd.com
   Where does all my time go?  <a href="http://www.macbsd.com/">Here</a>
                           and <a href="http://www.rrinc.com/">Here</a>