GitHub will be baking in support for Mermaid diagrams into their Markdown variant rendered for README.md etc.
Always interesting to keep up with what the competition’s doing ;-). Mermaid is a JS library easily embeddable, with sequence diagrams, entity relationship diagrams, gantts, alongside more traditional graphviz-style directed graphs.
Interesting. Similarly, there is pikchr (Pikchr: Documentation), a variant of the PIC graphics language, that can also be embedded in some markdown - but not here.
Pikchr consists of a single C program that produces SVG.
To-date, the biggest strength of Graphviz is mid-size and large graphs.
What might make Graphviz more attractive for smaller diagrams?
interactive or animated results (maybe not that hard?)
easier author control of node and/or edge placement (infinitely challenging)
class/style capability (maybe not that hard if done as a (built-in) pre-processor?)
Personally, I like fiddling with small-to-mid sized issues, but not at the expense of the code quality or the large-sized features.
From my perspective are the looks the biggest drawback of Graphviz. Having a few standard templates to choose from for a graph would be great. As an example, if you could with one parameter turn the visuals into a Mermaid diagram.