Many people leave a legacy, few leave a cottage industry!
One of the great things about Sir Terry Pratchett was the way that he would listen to ideas people threw in his general direction about his creations, then say “Okay then, have a go!” and let them be developed into marketable products which he would endorse and allow to be sold in his name.
In so doing he built up a large portfolio of friends and family (figuratively and literally) who worked with him to make the Discworld what it would become. I thought it would be a good idea to let you investigate some of these people in more depth, so…