So I decided I need to do some mindmapping.
Years ago for a totally unrelated project I had tried several different tools. One I got to be somewhat happy with was Freemind
Freemind main page @Sourceforge
Freemind page in Wikipedia
Apparently it also can run in less-performant systems besides Linux, is GNU-GPL licensed (thus free to use, copy, etc), and simply works real good. It can output folding HTML, bitmap, SVG, and many many more.
Here is an example, obviously with something that I do not care of losing my international rights on, which is an educational kit for doing electronics, whose main improvement is being solderless - thus uses wire wrap and clamping, instead of soldering components or using a breadboard. For example here my notes on ancient and thus very much out-of patent patents that refer to these technologies, so I can be sure I am not getting into any trouble by using them in a commercial product.
Click on the title above to see both the clickable HTML and a static PNG