auto generate class diagrams from solution?

uml, visual-studio-2008

Solution

You can create class diagrams inside Visual Studio. Just select New item > Class diagram from the project menu.

Problem

Is there a free tool that can create class diagrams for us? We want to run this on a solution and have the software generate a complete diagram of the classes and inter relationships for us. A UML - like diagram would be best. We currently have VSTS 2008 and it would be great if this was built in.

Original source