ASP.NET MVC 3 Reference
The topics in this section describe the public namespaces, classes, and interfaces that support ASP.NET MVC 3. These namespaces and classes are in the System.Web.Mvc assembly.
ASP.NET MVC implements the Model-View-Controller (MVC) pattern, which helps Web developers build Web sites that are easy to maintain, because MVC decreases the dependency between application layers. ASP.NET MVC also improves the testability of ASP.NET Web applications by supporting test-driven development (TDD).
Contains classes and interfaces that support the MVC pattern for ASP.NET Web applications. This namespace includes classes that represent controllers, controller factories, action results, views, partial views, and model binders.
Contains classes that support Ajax scripts in an ASP.NET MVC application. The namespace includes support for Ajax scripts and Ajax option settings.
Contains classes and interfaces that support asynchronous actions in an ASP.NET MVC application
Contains classes that help render HTML controls in an MVC application. The namespace includes classes that support forms, input controls, links, partial views, and validation.