Another graphing tool is Pikchr (https://pikchr.org https://pikchr.org) from the creator of SQLite; actually the SQLite doc SQL-statements diagrams were (re)don

Another graphing tool is Pikchr (https://pikchr.org https://pikchr.org) from the creator of SQLite; actually the SQLite doc SQL-statements diagrams were (re)done using the Pikchr. It's some kind of extension of PIC language. I'm not very proficient with graphing, so can't compare it to Graphviz, but a few examples I tried were relatively easy.