.NET 5

.NET 5 key features include

1. A single unified platform for everything including Windows, Mac, Web, Mobile, Cloud, IoT, Gaming, Machine Learning and Data Science.
2. Managed by open source community and supported by Microsoft.
3. Cross-platform with any device anywhere.
4. Supports all major platform capabilities for .NET Framework, .NET Core and Xamarin including Windows Forms, WPF, UWP, ASP.NET MVC, Entity Framework, LINQ and so on.
5. Scalable, fast, and high performance.
6. Smaller deployment and packages.
7. Support of the most productive IDEs and tools including Visual Studio, VS Code, VS for Mac, and Command Line Interface (CLI) 

.NET Languages and Runtimes

Mono is the runtime used as a part of Xamarin to build cross-platform applications. CoreCLR is the runtime used as a part of .NET Core.  

In .NET 5, both runtimes will be supported, evolve, and will continue to work together.

.NET 5 will support major compilers, languages, and runtime that are currently supported by .NET Framework and .NET Core. C#, F#, and VB.NET are expected to be a part of .NET. XAML is also a major component as a part of .NET supported languages.

What’s Replaced 
EF Core - Entity Framework Core is replacing EF 6 in .Net Core Framework.

Asp.net Core - Asp.net is replaced by Asp.net Core.

ASP.NET Core MVC - ASP.NET Core MVC unified ASP.NET MVC and Web API. Check the migration guide for porting asp.net mvc app into asp.net core mvc.

MSIX - Microsoft new packaging tool which replaces the old MSI package installer for desktop applications.

JsonDocument - New Json Document library from System.Text.Json.JsonDocument API to replace json.net. It is 2-3x times faster than old json.net.