I've used Groove here and there as well. But I don't want to collaborate, I want to outline. Small, but important, difference. I just want to load an app, load an outline, edit it - save it to a network drive somewhere in the universe and allow other members of my team to do the same, even if we're doing it simultaneously. Shinkuro is probably the closest of all of the collaboration apps, but what I'm thinking of is much more application, not function, centric. (i.e. "make it easier for me to collaborate in an Outliner", not "make me collaborate".)