title: Why is System.Web.Mvc not listed in Add References?
body: <p>Using C#, Visual Studio 2010.</p>
  
  <p>There is a namespace called <a href="http://msdn.microsoft.com/en-us/library/system.web.mvc.aspx" rel="noreferrer">System.Web.Mvc</a> documented on MSDN. The documentation for all the types in that namespace says that they are in <code>System.Web.Mvc.dll</code>.</p>
  
  <p>However, when I go to Add Reference, “.NET” tab, this assembly is missing from the list. Why?</p>