When you build an ASP.NET MVC 3 application and are ready to deploy it to your hosting provider, there are a set of assemblies you’ll need to include with your application for it to run properly, unless they are already installed in the Global Assembly Cache (GAC) on the server. In previous versions of ASP.NET MVC, this set of assemblies was rather small. In fact, it was only one assembly, System.Web.Mvc.dll, though in the case of ASP.NET MVC 1.0, if you didn’t have SP1 of .NET 3.5 installed, you would have also needed to deploy System.Web.Abstractions.dll and System.Web.Routing.dll. ...