.NET Core and BCL


Hi guys,

I have a Question regarding .NET Core and BCL.

As far as I understand the descriptions of the projects: .NET Core is only the a runtime even without the base class library. The base class library for .NET Core is developed in the corefx project.

But when I download the coreclr nuget package form the aspnetvnext package feed at myget.org, the package contains the coreclr and the base class library.

Is this also the case as soon as the package is final?
Is there already a package available with the coreclr only?



Logically, .NET Core is:

  • A runtime
    • CoreCLR
    • MRT (.NET Native runtime)
  • A framework
  • An app model

The CoreCLR runtime isn’t yet available on GitHub, but it’s coming, so stay tuned. Large chunks of the framework are already available in the corefx repo, but it’s not complete yet. You can think of the BCL as the combination of the runtime and the framework.

We currently don’t have a stand-alone package for CoreCLR. The packages you currently see aren’t well factored yet. We had to take shortcuts in order to make our current tools work with what we already have.

My expectation is that we’ll end up with the following packages:

  • A CoreCLR runtime package (clr.dll + mscorlib.dll + whatever other native dependencies the runtime has)
  • A package per framework assembly
  • Multiple packages for the ASP.NET web stack

We’ll probably also have meta-packages (i.e. a package that doesn’t contain anything but simply references other packages to make referencing simpler).

Does this help?


Definitely helpful and very much appreciated. Some exciting times ahead.Thanks a lot and best of luck.


Hi terrajobst,
thank you for your answer. This helps very much. In fact you say “the current packages are not factored well yet” then this meets my guess. Now I know it. I am looking forward to see the final packages. Do you have any idea when an alpha or beta package with the final structure will be available?

I am very interessed in .NET Core. To be able to deliver applications without dependencis on framework installations is great. I also wrote a .NET Core Clr host application. You can find it here:



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