Microsoft recently announced that they will be releasing the source code for .NET Framework 3.5 when Visual Studio 2008 is released towards the end of the year. That’s very unexpected news, indeed! Apparently VS2008 will actually let you step into the framework code while debugging. This is going to be immensely helpful in unwinding various evil bugs that cause errors deep inside the framework. It will also be (hopefully) educational to see how Microsoft actually implements some of the basic functionality of the framework. Here’s the announcement if you want to take a look.