What is the name of such diagrams?

Question

I would like to generate diagrams similar to this, but I don't have a clue what to look for.

Answer 1

That's a Syntax Diagram.

Syntax diagrams (or railroad diagrams) are a way to represent a context-free grammar.

Links:

• How to read syntax diagrams
• Many examples
• Creating syntax diagrams

Answer 2

These are called syntax diagrams or railroad diagrams for showing context free grammar

There is a tool which can convert BNF notation to railroad diagrams