The talks from JetBrains .NET Days Online 2020 are now available for everyone to watch. 

Introducing .NET Multi-platform App UI
.NET MAUI simplifies the choices for .NET developers, providing a single stack that supports all modern workloads: Android, iOS, macOS, and Windows.
 

Work in progress to add support for covariant return types to the .NET runtime. Soon we'll be able to override a virtual method returning `object` with a method returning `string`. Because of how array variance works, weird things might be possible in IL. 

class Base
{
    public virtual IntPtr[] Fun() => null;
}

// This is obvious pseude-code because C# won't let us introduce methods differing
// in return type. C# also requires to be explicit about "virtual" and "override".
// But IL... not so much.
class Derived : Base
{
    // overrides Base.Fun on 32bit platforms.
    public override uint[] Fun() => null;

    // overrides Base.Fun on 64bit platforms.
    public override ulong[] Fun() => null;
}

Top 10 books every .NET/C# developer should read

C# Number And DateTime Tips 

The following improvements are in Preview 1:

• Regular expression performance improvements (3-6x Faster)
• Code quality improvements in RyuJIT
• Assembly load diagnostics added to event pipe
• Event pipe profiler APIs
• .... 

Starting with .NET 5 Visual Basic will support:

• Class Library
• Console
• Windows Forms
• WPF
• Worker Service
• ASP.NET Core Web API 

18 years ago today, on stage at the @VisualStudio launch event, @BillGates introduced .NET wrapped with ❤️ 

PascalABC.NET is:

• The new generation Pascal programming language that combines simplicity of classic Pascal, a great number of modern extensions and broad capabilities of Microsoft .NET Framework.
• Free, simple and powerful IDE.
• Built-in form designer for rapid development of Windows desktop applications.
• Free LGPLv3 license.