What file uses .md extension and how should I edit them?

Question

On GitHub, several projects have README.md files. It seems like a simple format file to express text and pictures.

I guess there is an editor or syntax

Answer 1

If you are creating .md files for your .NET solutions I recommend the Visual Studio 2015 extension Markdown Editor as it has a preview panel so you can see your changes in real time.

EDIT: This also should now work with Visual Studio 2017.