Anti-alias works for Draw but I can't see how to get anti-alias for font : is it possible anywhow (including hacking rebol vid ...) because font in the picture generated below is not nice:

view layout [
    box 278x185 effect [ ; default box face size is 100x100
      draw [
        anti-alias on
        ; information for the next draw element (not required)
        line-width 2.5 ; number of pixels in width of the border
        pen black      ; color of the edge of the next draw element

        fill-pen radial 100x50 5 55 5 10 10 71.0.6 30.10.10 71.0.6

        ; the draw element
        box     ; another box drawn as an effect
          15     ; size of rounding in pixels
          0x0 ; upper left corner
          278x170 ; lower right corner
      ]
    ]
    pad 30x-150
    Text "Experiment" font [name: "Impact" size: 24 color: white]
    image http://www.rebol.com/graphics/reb-logo.gif
]