The EER diagram markup language
ERML is a markup language for describing entity-relationship diagrams, including IS-A (subclass) relationships. It is built for Chen's Notation.
Read SPEC.md for the full specification.
Some examples are present in the examples folder.
To generate the graphviz file, run ./erml.sh <filename>. This will generate graph.gv, a graphviz file.
The visualiser is WIP, but Viz.js works.