Outliners for coding and comments
Two screen shots, one with the code narrative expanded, one with it collapsed, show why editing in an outliner works for managing complexity in code.
by Dave Winer Wednesday, January 4, 2017

Note to non-believers. These two screen shots show why code written in an outliner can be fully documented in place without affecting readability. 

Screen shot #1 -- comment at top of function is expanded revealing a narrative for why this complex bit of code exists. 

Screen shot #2 -- the comment at the top is collapsed. All you can see is that there are change notes at the top, only read them when you want to see what's there.