Yeah that's a good point, CoreCLR only has the single/main AppDomain code and Rotor was only 'sort of' .NET 2.0, but with a different GC and JIT.

So without asking Don Syme himself we can only guess.

> I'm not sure if fullblown .Net CLR implementation was released yet

No and AFAIK they don't plan to. There's 'Reference Source' [0], but that's the Base class libraries only, not the CLR itself.

[0]: referencesource.microsoft.com