By core functionality, I mean the ability to simply initiate editor instances and plot nodes (I'm not so worried about the engine--yet), while keeping UI completely original?
Or, is this a complete product where everything is tied together? Sorry if I'm being too vague.
The project is currently split into 5 or 6 packages - in order to help do that.... but they do also rely on each other as well so while you could take just the editor you would still need to create/emulate most of the other parts in order to feed it correctly. So net is it is fairly much tied together at present.