Announcing .NET 5.0 Preview 3

Rich Lander [MSFT]

Today, we’re releasing .NET 5.0 Preview 3. It contains a set of new features and performance improvements. We’re continuing to work on the bigger features that will define the 5.0 release. The .NET 5.0 Preview 1 post covers what we are planning on building for .NET 5.0. Please take a look at the post and the dotnet/designs repository and share any feedback you have. And, of course, please install Preview 3, and test your workloads with it.

You can download .NET 5.0 Preview 3, for Windows, macOS, and Linux:

ASP.NET Core and EF Core are also being released today.

You need to use Visual Studio 2019 16.6 to use .NET 5.0. Install the latest version of the C# extension, to use .NET 5.0 with Visual Studio Code. .NET 5.0 isn’t yet supported with Visual Studio for Mac.

Release notes:

Let’s look at some of the improvements in Preview 3.

Code quality improvements in RyuJIT

Every release includes a set of changes that improve the machine code that the JIT generates (we call this “code quality”). Better code quality means better application performance.

System.Text.Json improvements

.NET SDK Support for .NET Framework Assemblies

The .NET SDK will now auto-reference the Microsoft.NETFramework.ReferenceAssemblies NuGet package given a .NET Framework target framework in a project file. This change enables building .NET Framework projects on a machine without the required .NET Framework targeting pack installed. This improvement is specific to targeting packs, and doesn’t account for other dependencies that a project may have.


Please take a moment to try out Preview 3, possibly in a container, a VM. We’d like your feedback on the quality of the release. There is a lot more coming, over the next several months, leading up a November release.


Discussion is closed. Login to edit/delete existing comments.

  • Soheil Alizadeh 0

    typo on dotnet/rintime #32969

  • Chris Bergmeister (MVP) 0

    Typo in Closing section: It still mentions the previous ‘Preview 2’

  • Tony Henrique 0

    .NET 5 will be awesome!

  • Nick Ac 0

    Just wondering, any updates on the Java interop? Also, will it be able to target desktop VMs?

  • Rojan Gharibpour 0

    What is the status/plan on the Java layer?

  • Patrick Deschênes 0

    About Swift interoperability in .NET 5, I was wondering what features are planned for .NET 5.

    I am asking the question because this topic got raised on the Swift forum lately and people there didn’t seems to know what
    this .NET 5 Swift interoperability meant.

    For example :

    • Would it use the official Swift implementation or one provided by Microsoft
    • Would it work on Windows
    • Would we be able to call .NET from Swift
    • Would we be able to call Swift from .NET
  • Kelvin Mwenda 0

    Will file stream for SQL server be available in core in .net 5???

  • theuserbl 0

    What happens with Mono after .NET 5?
    .NET 5 is the real successor of .net Core.
    .NET Framework will be discontinued.
    And what is with Mono? Is it then deprecated, too?

    In the picture, I have seen on a news side, it seems to be coexisting with .net 5

    • Marina Sundström 0

      .NET 5 is about unifying .NET by sharing implementation and tools.

      Microsoft and the community have been working towards making Mono run the same implementation of the Framework Class Library as .NET Core.

      In the end, there will be two CLR implementations that share the same Framework Class Library.
      (Core)CLR is for desktop and cloud. Mono Runtime will be the one you use when building embedded and mobile applications with Xamarin.

      • gc y 0

        Why to maintain two CLR? Why not combine them to one?

        • Charles Roddie 0

          Combining them into one is a very large task and not feasible by November this year.
          .Net 5 (CoreCLR+MonoVM both running the same CoreFX) represents a half-way point that took years of work.
          After .Net 5 I am sure they will continue to consolidate mono and coreclr until there is only one runtime.

  • Malachi Burke 0

    ARM64 support – very awesome. Does your long term roadmap continue to include ARM64 support? We’re evaluating .NET Core usage for a long-term embedded Linux system

    • Hernan Martinez 0

      I’m dying to find out if .NET 5 will have WPF support out of the box on ARM64

      • Jack Bond 0

        It won’t. An army of brain dead zombies compose .NET project management.

        After all, why could you possibly want a cross platform UI framework which would allow you to create app stores for MacOS and Linux?

        The math is really simple. Which would be better? Have your developers

        1) Waste millions of hours coding with a moronic framework like Electron?
        2) Remove Windows dependencies from WPF and provide a cross platform UI framework that would benefit EVERYONE?

        P.S. If you go with 2, you just might win back a few Silverlight developers who you lied to and completely f****d over.

        • Tsahi 0

          You are saying “Remove Windows dependencies from WPF” as if that’s a day’s job. WFP is built on top of DirectX, and was designed as a Windows technology. removing the Windows dependency will probably require rewriting half of it.

        • Troy Robinson 0

          Checkout something called Avalonia. It has what you want. If you don’t like that GTK#, if not that Eto.Forms

      • Austin Harris 0

        FWIW if anything..

        Not quite what your asking for, but I’ve had similar issues with building cross platform UI. In the end I’ve started going down the Blazor WASM route. Not quite WPF, but at least you can do your Front-end work in C# and still be Linux and mac friendly. Browser rending performance is hardware accelerated, you just have to find a way to launch your browser window in a chrome-less mode if your going for that native UI look.

  • tom light 0

    Really looking forward to the new version. If I have a bit of feedback around the new dotnet new templates (specifically for F#) where’s the best place to go?

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