Any time Graphviz is not enough for whatever reason, I’ll usually reach for TikZ. This is part of the TeX ecosystem, but I often use Graphviz by itself and past

Any time Graphviz is not enough for whatever reason, I’ll usually reach for TikZ. This is part of the TeX ecosystem, but I often use Graphviz by itself and paste the resulting images into web pages, presentations, or design docs. TikZ lets you control the path of arrows to a fault, so you can easily get the straight arrows and 90-degree turns, rather than the “anything goes” automatic layout that you get in Graphviz. I use it pretty often to illustrate state machines, system diagrams, or flowcharts. Well, or I’ll reach for Inkscape.