Building HTTP services with ASP.NET Web API in MVC 4 Beta
ASP.NET Web API is a new framework shipping in MVC 4 Beta that makes it easy to build and consume HTTP services that reach a broad range of clients, including browsers and mobile devices. ASP.NET Web API is an ideal platform for building RESTful applications on the .NET Framework. ASP.NET Web API supports full content negotiation, a modern HTTP programming model, asynchronous programming and can be both hosted both in and out of IIS while preserving familiar MVC abstractions.
Daniel Roth