A long time ago I used to use a Windows Idea Processor written in Visual Prolog! A search for a Linux equivalent has been unsuccessful but think this new Coggle maybe OK.
Here are a couple of screen dumps from their Free public Gallery. There are many more which may be of interest.
I took a look at these and found them pretty overwhelming. I think I will crawl back into my bubble.
On a more serious note, that is a very interesting way of summarizing all there is to know about certain topics. We should probably all take a look at them just to put our self-perception on a more realistic basis and realize that the learning just never stops.
It reminds me of a couple of definitions I was given when I started programming.
A switch is something you set in one part of a program to indicate that you should not do something in another part of the program because it was done somewhere else.