My experience as an author of non-linear texts is confined to a narrative project my 5th grade teacher had us do. This is 1996. We used a program called Hyperstudio, a sort of Powerpoint meets Kidpix which allowed you to use buttons (links, essentially, but they were called buttons in Hyperstudio) that transported you to another page.

The thing was, being 1996, our classroom only had a few computers, so the teacher had us diagram our 2nd person plots beforehand so as to speed up the hyperstudioing once it was our turn on the machine.