From what I can tell, not much, but it adds another form of extension (via tags) which you can arguably say you also had in XML (via namespaces).
Other than that, the major difference seems to be that EDN does not have a root-element or requirement for such, and as mentioned in the introduction can be used for streaming and real-time content etc.
Other than that, the major difference seems to be that EDN does not have a root-element or requirement for such, and as mentioned in the introduction can be used for streaming and real-time content etc.