Graphviz

An open-source graph visualization software suite that renders structural representations of graphs and networks from the DOT text specification language. DOT files describe nodes, edges, attributes, and layout hints, which Graphviz layouts engines (dot, neato, fdp, circo, twopi) convert into visual diagrams. Like Mermaid, Graphviz is valuable for accessibility work because its source format preserves semantic structure (which nodes are connected, in what direction, with what labels) independently of the rendered pixels, enabling automated generation of accessible tabular, navigable, and tactile outputs.