For mind mapping, after a bit of tinkering, I greatly reccoment draw.io (it's a webapp)
Thought less customizable than Yed, it has the great advantage of allowing several people to work on the same file at the same time. You can use it in conjonction of google drive or Dropbox for even more sharing goodness.
The main drowback (for me a least) being that it's a webapp.
But it's free, it's rather effective and there a lot of tool for integration to other services, as well as plugins for browsers and the google suite.
Articy looks damn fine indeed... I think I'll get it one day. But as of now, Draw.io is more than enough.
Another tool that I use and I reccomend (though a bit more underground) is CherryTree.
It's basically a local wikipedia maker. It allows to create notes, organize them, create links to other notes, anchors, files etc ...
It's kind of a powerhouse of notetaking and management.
One of the advantage being that you can export whatever part of your tree you wish as a Pdf or HTML file, allowing people to access it as if it was a wiki (with a map of the notes automaticaly created).
Plus it's totally free, so I would greatly reccomend you to at least try it.
The main drawback is the lack of online sharing and silmutaneous editing.
Though it has a portable version of the .exe, allowing you to install it on a USB / GoogleDrive / Dropbox etc ... along with the files you are working on. It's not perfect but it's more convinient.