What's the name for this type of flowchart?

Question

Take a look at this; it's very obvious how it works and what its purpose is:

_{(source: json.org)}

1. What's this type of chart called?
2. Can I make this kind of chart in Visio?
3. What software do you recommend for making this kind of chart?

Answer 1

It's called a railroad diagram. It can more specifically be called a syntax diagram. Not sure about Visio support but other tools can get the job done: What is a good tool for creating railroad diagrams?

_{(source: antlr.org)}

If you have a grammar file you can try to get it working in ANTLR Works, which is specifically built for working with the syntax and grammar of languages.

Answer 2

These are called Syntax diagrams (or railroad diagrams).

They can be created with Visio or Creative Docs .NET

See here for more info:

Tool for generating railroad diagram used on json.org

Answer 3

It is a syntax diagram; not sure if there is any visio addon to paint this kind of chart.