Step in a little deeper
Yesterday Microsoft announced that it is
releasing the source code for .NET Framework libraries under the Microsoft Reference License.
More importantly (to developers anyway) is that a new feature of Visual Studio 2008 will allow debugging not only into your own code but also to step into .NET Framework source code!
The release will include the Base Class Libraries, Windows Forms, ASP.NET, System.Data and my favourite bit, WPF.
So obviously that doesn't include the entire framework, that's because each library needs to be subject to a code review so, as time allows, expect to see more of the Framework released under the license.
It's probably worthwhile noting what the license covers. The reference license means you can view the source code but not modify it or redistribute it, and the source code will be downloadable by anyone who accepts the license agreement.
The really cool bit about this is the workflow. When you are in a debugging session and you want to step into Framework code, the debugger queries a remote server for the version of the symbols that match the binaries used in the application being debugged. If it finds the correct version, it downloads the source files on-demand. This is the same workflow for all source code that will be added in the future, whether managed, unmanaged, 32-bit 64-bit, desktop, mobile etc!
Check out ScottGu's blog for me information!