[O] Collaborative Team Project Management with Orgmode?

[Tory S. Anderson]

I've relied on Orgmode heavily for over half a decade, and I'm 
loathe to leave it. But what solutions have been found out there 
for using it collaboratively (where others are not using emacs), 
rather than just for personal task management (where it excels)? 
It has some integration with Trello, I know; some of my co-workers 
are advocating BaseCamp (...) and PivotalTracker. PivotalTracker 
looks pretty good, but I would rather find a way to leverage 
orgmode in a way that facilitates collaboration. What has worked 
for you?