Disgruntled Fungus (666) writes "According to an official blog, Microsoft has decided to release the source to its base
.NET classes. The source to classes such as System, IO, Windows.Forms, etc. can now be viewed and used for debugging purposes from within Visual Studio. Instructions to do that are here. In the interest of disclosure, the source code has been released with a read only license and "does not apply to users developing software for a non-Windows platform that has "the same or substantially the same features or functionality" as the .NET Framework.""