Why is System.Web.Mvc not listed in Add References?

Question

Using C#, Visual Studio 2010.

There is a namespace called System.Web.Mvc documented on MSDN. The documentation for all the types in that namespace says that they are

Answer 1

"OK, adding that XML to the Web.config works, but it doesn’t answer the question"

It should be there. By default the add references list seems to be ordered, but its not the case. Hit the name header and look again.