Last I checked (Spring this year), Silverlight 3 and 4 were not supported on Moonlight.

>Hi Mel,
>
>For WinForms, there are various toolkits what will run with Mono: http://www.mono-project.com/Gui_Toolkits
>
>Silverlight apps will run on Moonlight: http://www.go-mono.com/moonlight/
>
>Silverlight/Moonlight will, I think, give you the most bang-for-the-buck. It can do browserless apps that look just like any other spiffy application.
>
>Hank
>