That's not exactly a fully supported toolset. There is another C# to js compiler http://projects.nikhilk.net/ScriptSharp which is AFAICT another side project.

If one of these were to stick - it would first need to be supported be a somewhat larger organization (ala apache foundation for java components, or google for GWT/Closure).

For the F# developer, WebSharper ( http://websharper.com/ ) seems to offer a great implementation based on the Formlets abstraction. For some theoretical background, have a look at http://groups.inf.ed.ac.uk/links/formlets/ which has some articles describing the Form abstraction by Philip Wadler, et al.