Treesheets. an outliner

Treesheets is an outliner+ mindmapping very amazing
you start for example here, drawing your first table in a simple way
you can keep adding tables inner and outer, for example here
and more and more…

and more and more until infinity (the part where we were now looks illegible because of zoom, but you can zoom in again of course)

you can see how many tables inside of tables can be like an outliner in two dimensions …
its pretty awesome

cons = non-active development since at least 2014 but still… its a good tool