To me the left one looks more like a Dicemillia (or whatever it is typed ;0)) yet not exactly.. strange thing. Anyone knowing older Arduinos or Prototypes might answer you that... It looks interestering though... yet i would guess that 3v3 and 5v are used as they are quite common on electronics whereas i never saw 9v...
edit on second thought this doesnt look like a real Arduino as it wouldnt be Shield compatible if you look at the power sockets.. maybe it IS some prototype or specialised one?