Dapper is a simple object mapper for .NET and it is virtually as fast as using a raw ADO.NET data reader. An ORM is an Object Relational Mapper, Which is responsible for mapping between database and programming language. For that reason, it is called King of Micro ORM
Microsoft has an announced WPF & Winform are as an open-source. Both WPF & Winform are the most popular technologies in dotnet. This UI framework for building Windows desktop application that supported on .NET Core.