Microsoft Volta

The Volta technology preview is a developer toolset that enables you to build multi-tier web applications by applying familiar techniques and patterns. First, design and build your application as a .NET client application, then assign the portions of the application to run on the server and the client tiers late in the development process. The compiler creates cross-browser JavaScript for the client tier, web services for the server tier, and communication, serialization, synchronization, security, and other boilerplate code to tie the tiers together.

Learn more about it @ http://labs.live.com/volta/