##[Blitz 2D/3D](http://www.blitzbasic.com/Products/blitz3d.php), 126 bytes

    Graphics 180,180
    ClsColor 255,255,255
    Color 128,0,128
    While 1
    Cls
    ang#=ang+3
    Plot 90+67*Cos(ang),90+67*Sin(ang)
    Delay 500
    Wend

Unfortunately, this language is only supported on Windows (though it *may* run in Wine).