Are there any differences between the programs Sandcastle Help File Builder, DoxyPress, Doxygen?

Question

Questions.

1. Are there any differences between the programs Sandcastle Help File Builder, DoxyPress, Doxygen?
   Or are these programs the same in functionality and you can use any of them?

Description.
I'm looking for a program to document the code.

Basic requirements:
- Free of charge;
- ability to work in Windows;
- ability to build UML diagrams (class diagrams) on the basis of an existing project;
- formation of documentation based on an existing project.

I assume to use one of the programs:
- Sandcastle Help File Builder (SHFB);
- DoxyPress;
- Doxygen.

I skimmed through the program documentation and compiled a table.
Table of comparisons

| Candidate | Windows | UML diagram | Documentation | Free | 
| ----------| --------| ----------- | ------------- | ---- | 
| SHFB      | +       | ?           | +             | +    |
| DoxyPress | +       | ?           | +             | +    |
| Doxygen   | +       | ?           | +             | +    |

I expect to develop applications on .NET.
Desktop(C#).
- WinForm
- WPF

Web(C#, JavaScript, jQuery).
- ASP.NET;
- Blazor;