Which program generates grammar grams?

Question

I see grammar graphs on sites for SQLite and JSON . What program can I use to create these cute images?

Answer 1

this answer found that SQLite uses a custom script for graphics on its website. The graphs on json.org are made in visio .

Answer 2

I don’t know if they have any kind of program that automates it, but you can make such graphs using GraphViz . I have done this in the past.