The sadest part is that you can't even blame Ingo for not giving more documentation on his work, because he has collected an impressive collection of documentation on the subject he was working on. And it was published on the web (I think it still is).
Now maybe the sources are a bit hard to get into. I know because he uses all the great possibilities of C++ so you have to know and understand them to really be able to read the code.
Anyway, this is not a topic about Ingo