We are releasing the source code for .NET Framework base class libraries under the Microsoft Reference License, and the source code will be downloadable and viewable by anyone who accepts the license agreement.
addition, Microsoft will introduce a capability in Visual Studio 2008
to allow you to debug into the .NET Framework source code using Visual
Studio. With this capability, when you are stepping through code, you
will be able to step into the source code for the .NET base class
This release will include the Base Class Libraries
(BCL), Windows Forms, ASP.NET, System.Data, and WPF. BCL includes many
of the basic classes in the framework including collections, string and
text handling, IO,serialization, remoting, and others. We plan to
include additional libraries into the set as time goes on.
ScottGu has the details.