Just a note that ConceptMap.io now uses Visjs instead of D3js as its
graph drawing library, primarily for displaying thumbnail images from
Wikipedia and Wikidata. Attached is a sample image of a concept map
whose subject is Q42 (Douglas Adams), and you can view/edit the live map
by clicking this link:
http://bit.ly/1NlbpRi
Thanks for your help and feedback for this update.
Regards,
James Weaver