What program(s) generate grammar graphs?

Question

I see grammar graphs on the websites for SQLite and JSON. What program can be used to generate these pretty pictures?

Answer 1

I don't know if they have some program that automates it, but you can make those kinds of graphs with GraphViz. I have done so in the past.

Answer 2

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