ASP.NET MVC4 Web API Stack Diagram – currently in development
NOTE: The following diagram is NOT a representation of the stack of Release Candidate(RC) version. But it is something which is currently in development and most probably would be available for the final release. If you would like to look at the diagram representing the stack of RC version, you can go here.
Henrik provides a nice overview of this feature over here.
(click the image to get a larger image)