Wednesday, October 03, 2007 10:58 PM  

The .Net Framework 3.5 Source Code will be released later this year as part of the VS 2008 (Orcas) release.
(announced in ScottGu's Blog http://weblogs.asp.net/scottgu/archive/2007/10/03/releasing-the-source-code-for-the-net-framework-libraries.aspx) 

This isn't earthshattering news since the code is already "visible" using tools like Reflector. But now we will have the complete source code detail (private variables names, comments, etc.) and we will also have the ability to debug it with Visual Studio 2008, work with it in a much more robust and easy way, and better understand exactly what's "under the hood".
See also:

• Shawn Burke's BLog - Making .NET Framework Source Available to Developers
  http://blogs.msdn.com/sburke/archive/2007/10/03/making-net-framework-source-available-to-developers.aspx
  
• Matt Winkler and David Tesar catch up with Shawn Burke to talk about the announcement today that the source for the .NET Framework will be made available
  http://channel9.msdn.com/Showpost.aspx?postid=345805
  
• Also check out the Podcast on Scott Hanselman's "Hanselminutes"
  http://www.hanselman.com/blog/HanselminutesPodcast83MicrosoftToReleaseNETFrameworkLibrariesSource.aspx
  http://www.hanselman.com/blog/HanselminutesPodcast83MicrosoftToReleaseNETFrameworkLibrariesSource.aspx