I have used Viz.js since 2012 in Aude [1], a tool to play with Finite State Machines, in order to display results from algorithms like minimization, determinization and other common FSM-related algorithms, and also to provide an automatic redraw feature when drawing FSMs. The user can also input FSMs in a small description language, and they are drawn automatically using the same system.

For people who don't know Viz.js, it is basically GraphViz compiled for the web as ASM.js using emscripten plus a convenient way to call it. Usage is simple: you give the DOT code, and it returns an SVG document as string (other formats are actually supported).

Viz.js is awesome. Thanks Mike Daines! And obviously, thanks Graphviz!

Webgraphiz uses a viz.js file. Is it actually the same Viz.js? (edit: yes, it is)

[1] https://aude.imag.fr/