Nikhil has released a prototype of Script#, a toolkit that brings the C# developer experience (programming and tooling) to Javascript/Ajax world, similar to the recent Google Web Toolkit.

A Better Scripting Environment

The fundamental goal was to improve the state of the art in scripting. This goes way beyond the usual things that come to mind at first thought: compile-time checking, and intellisense or statement completion. I do think these are super-useful, and would be valuable in and of themselves. As we worked on Atlas we were also thinking of a great tools experience, and we explored different approaches and technologies for achieving this. Script# is a prototype of one such exploration. It attempts to address some programming environment requirements:

More Info: Nikhilk.net