Debugger that allows debug .NET framework

Recently I found interesting program called dnSpy https://github.com/0xd4d/dnSpy that allow to debug .NET application without need to install anything. It also can allow debug .NET applications without source code (including .NET framework itself), it allow to edit assemblies, allow to edit in C#, IL etc.

Highly recommended application and it should be in tools belt of any .NET developer.