Spring 3.0.x and greater has introduced some nice decoupling of the MVC annotations and the Servlet API. Thus in theory one could create a completely different Spring Web MVC framework using Spring's existing annotations (albeit the view adapters would have to be rewritten) for something like Netty.

That is if your just using the annotations (ie @RequestMapping) you could in theory switch from Servlet container to non servlet container (Netty).

The bulk of the work would be porting over the existing HttpServlet MVC (spring-webmvc) code to use Netty's request/response abstraction.

I was curious if anyone had started down this path?

This has been done before if people remember the good ole' portlet code.