Microsoft had made available (some of) the .NET Framework source code, but only for Visual Studio 2008 users, at least for now. You can read the announcement in Scott's Gu blog, follow detailed steps and read the details on Shawn Burke's blog, see many comments on blogs around the world, watch videos, and more.

This is certainly a positive thing. Although the license has some restrictions (sorry, I haven't read it and don't know the details), it seems a very positive move as you'll be able to debug your code into the framework. This is something VCL developers (but also Java developers) have been able to do for a lot of time. However, on the VCL side, we can also open the source code files and read them, something that doesn't seem to be so easy with the .net source code.

I've seen complains because this feature is not available to Visual Studio 2005 users (at least for now). By default, you downlaod the source code every time you debug, although there are options to cache the data. Still, from what I understand, you don't get the plain source code files in a folder... I guess this makes it impossible to use this feature from Delphi for .NET.

Some of the Microsoft bloggers mention although Kerem Kusmezer (whoever he is) has written a "Reference Source Code Downloader" which I doubt is legal (he has the same doubt himself, so he's asking before making it available). Well, I guess there is hope... I for one would like to read some of that code and compare it to other libraries...