This is an integration of this implementation of a Fishbone or Ishikawa diagram, which shows contributions of different levels of a hierarchy to a main concept, with a Markdown editor for making quick diagrams.
The diagram is implemented in d3.js, while rich-text editing is provided by CodeMirror, and marked handles Markdown processing.
If you have insights, or make modifications, share them on the thread on the d3-js discussion group that spurred this work!