The ASP.NET MVC Framework is a Microsoft web application framework that implements the model-view-controller (MVC) pattern. Based on ASP.NET, it allows software developers to build a Web application as a composition of three roles: Model, View and Controller.
A model represents the state of a particular aspect of the application. Frequently, a model maps to a database table with the entries in the table representing the state of the application. A controller handles interactions and updates the model to reflect a change in state of the application, and then passes information to the view. A view accepts necessary information from the controller and renders a user interface to display that.
The latest stable version - MVC 3 - is available from the Microsoft Download Center website.