.NET Core is a specific .NET platform while .NET Standard is a specification that many .NET platforms, including .NET Core, implement.

In other words, .NET Standard is POSIX for .NET.

Small correction: .NET Core _will_ implement it. It has to grow quite a bit to get there.

At least, that's my reading, but they manage to be fairly confusing by mixing present tense and future tense with two different names:

"- .NET Standard is a set of APIs that all .NET platforms have to implement. This unifies the .NET platforms and prevents future fragmentation.

- .NET Standard 2.0 will be implemented by .NET Framework, .NET Core, and Xamarin. For .NET Core, this will add many of the existing APIs that have been requested.

- .NET Standard 2.0 includes a compatibility shim for .NET Framework binaries, significantly increasing the set of libraries that you can reference from your .NET Standard libraries.

- .NET Standard will replace Portable Class Libraries (PCLs) as the tooling story for building multi-platform .NET libraries."

So, do we have ".NET Standard" now and ".NET Standard 2.0" in the future? If so, why don't they say ".NET Standard 2.0 will include a compatibility shim for .NET Framework binaries"?

On the other hand https://github.com/dotnet/standard/blob/master/netstandard/p... seems to indicate the two are synonyms, and version 2.0 is the first version of this framework.

> So, do we have ".NET Standard" now and ".NET Standard 2.0" in the future?

There are three key versions (and several others; they have 1.0 through 1.6 and 2.0) of .NET Standard referenced; the key versions are 1.5 (supported by .NET Framework 4.6.2 and later and .NET Core 1.0 and later), 1.6 (supported by .NET Framework vNext and later and .NET Core 1.0 and later), and 2.0 (supported by .NET Framework 4.6.1 and later and .NET Core vNext and later).

So, in a blog post titled "Introducing .NET Standard", it turns out .NET Standard already has 8 different versions?

Also, rereading the article, I notice "When we shipped .NET Core 1.0, we also introduced .NET Standard."

This text really could do with a good editor.

> it turns out .NET Standard already has 8 different versions?

I think the versions prior to v1.6 were retrospectively defined based on the common capabilities of pre-existing platforms; v1.6 was what .NET Core 1.0 supported and .NET Framework vNext will support (2.0 is what .NET Framework 4.6.1 supports and what .NET Core vNext -- and vNext of MS's other platforms -- will support, and beyond 2.0 there will be more synchronous development across different platforms.)

That's exactly what happened, yes.

That's actually a fair point. I probably should have used a different wording.

> Small correction: .NET Core _will_ implement it. It has to grow quite a bit to get there.

.NET Core _already_ implements .NET Standard 1.x. It _will_ implement .NET Standard 2.0.

They're considering .Net Framework 4.6.x to be the guideline for Standard 1.x, And that when Core 1.0 hits, it will support .Net Standard 2.0.

My guess is jumping to 2.0 for future implementation base is to avoid conflicts with .Net Core 1.0 (though may exacerbate the issue)

It's a common API for things like networking, IO, threading, serialization, and so forth.

Library authors need to do refactoring to achieve compatibility across .Net Platform (old stuff, Windows-only) and .Net Core (new stuff, cross-platform).

This is the bridge for library authors to transition from being Windows-only to cross-platform.

Think about library authors that need to write for both Python 2 and Python 3, there needs to be a common API between both, and this is it: .Net Standard.

Meanwhile .Net Core is cross-platform build tooling and a minimal API.

I believe this was discussed a while back by Scott Hunter in his interview on the .NET Rocks Podcast, who is the PM of all the .NET Platform. He explains, almost apologetically, what all this entails. Needless to say this is not news. I do not follow .NET that much until Core meant Linux, so I listen to things like this.

http://dotnetrocks.com/?show=1291

(I apologize in advance for anyone who uses JS blocking like me; open it in your other YOLO browser if you know what's good for you; the .NET Rocks team loves Angular a little too much.)

The article literally states the difference.

It's the API definition that will be shared by .net Core/full framework/asp.net/xamarin.