Bring back .NET Standard support

[cheenamalhotra]

We've heard feedback from the community and customers impacted by dropping .NET Standard support.

As a result, we're planning to reintroduce .NET Standard support in MDS. This will allow applications to continue compiling with .NET Standard dlls and target applications to .NET Standard targets; while the .NET runtime will place correct DLLs for targeted frameworks for runtime use.

Related issues and discussion threads:

• Drop support for .NET Standard  #2340
• Microsoft.Data.SqlClient 6.0 and .Net Standard #3115

[MSACATS]

Thank you, this will save us a lot of pain. It's the first time in a while that I can remember the new .NET ecosystem reversing a decision in order to make our lives easier, so I appreciate it

[LuisApplivity]

Concerns:

• Will .NET Standard 2.0 work as correctly as it did with MDS 5.x and earlier?
• Will a later version of MDS (e.g. 7.x) ignore this fix and remove support again?
• Will other 1st party .NET ecosystem projects/libs make this same mistake again?

I just can't trust the ecosystem anymore. Can't safely pitch it to internal nor external clients. Can't promote nor defend it when discussing it with others, after this and all the other betrayals. Trust is difficult to build, nigh-impossible to regain once lost, and this also applies to those promoting it, which is why we can no longer safely do so.

[cheenamalhotra]

I understand your concerns and they're valid. Responding to them below:

• Will .NET Standard 2.0 work as correctly as it did with MDS 5.x and earlier?
  • .NET Standard 2.0 DLLs are compile-time assemblies only, and will expose the same APIs as before with MDS 5.x and earlier versions. We will not ship runtime assemblies for .NET Standard 2.0 as there is no .NET Standard 2.0 runtime as such. You can help us here by consuming our next preview release and letting us know if you notice any differences/concerns and we will be actively addressing any concerns before stabilizing the release.
• Will a later version of MDS (e.g. 7.x) ignore this fix and remove support again?
  • No, .NET Standard 2.0 DLL is here to stay. Our active releases are always based off main branch, and 7.0 will be built off main too.
• Will other 1st party .NET ecosystem projects/libs make this same mistake again?
  • We cannot speak for everyone in the .NET ecosystem as all .NET product teams work independently and have the freedom of making decisions based on their customer needs.

I would recommend voicing your concerns to the dotnet/runtime maintainers as they are the primary maintainers of the .NET ecosystem, and can make recommendations on documentations/other platforms about how .NET Standard should be supported.