is .net ( or any part of it ) open source?

Question

is any code related to .NET/ASP.NET or BCL open source? If so where can this be downloaded?

Answer 1

There is the Mono project, which is an open-source cross-platform implementation of .NET, but the "standard" Microsoft implementation is not free-to-copy.

Answer 2

Microsoft's implementation of the CLR is not open source. However, a stripped down version of it, Rotor, is.

That said, Mono is probably better supported when compared with Rotor, so if you're looking for something to distribute I'd use Mono.