A recent article by Scott Guthrie

http://weblogs.asp.net/scottgu/…/releasing-the-source-code-for-the-net-framework-libraries.aspx

reports that the source code for the .NET framework libraries will be made available with the releases of .NET 3.5 and Visual Studio VS2008 scheduled for later this year.

It will be released under the Microsoft Reference License (licence details here).

Dynamic loading of the .NET framework debug symbols and source code will be integrated within the VS2008 debugger - the data being made available from a Microsoft hosted web server.

Providing access to the source code and integration within the debugger will provide a powerful, and essential, tool for all .NET developers.