I've got the second edition, Quill Press, 2001. I initially got it and read it in or around 2003, and it's one of a relatively small number of books I am willing to say Changed My Life. It helped me better understand myself; it gave me confidence that I could raise a kid who was like me. Which turned out to be fortunate, as at least one of my kids shares a lot of the emotional difficulties I have.
Greene's approach is Very Simple, but that does not mean it is necessarily Easy to implement -- altho once you are well along the path, you may find yourself confused and irritated that everyone else doesn't Just Get It. Indeed, that is the basis for my decision to reread the book. I did not expect to learn how to do what Greene suggests (I already had); I hoped instead to learn how to explain it to others. I will discover in the coming months and years whether I was successful.
Greene reframes children who throw temper tantrums long after more ordinary children have stopped. Rather than treating these children as unaware of the rules their parents and teachers expect them to follow, or unmotivated to follow them, Greene suggests that some children (people) have a variety of problems (with executive function, language, social communication, self-knowledge, sensory processing, general irritability perhaps as an effect of some or all of the above, etc.) that make them more likely to experience frustration and emotionally disregulate as a result (altho he doesn't ever use that word, I don't think). Parents and teachers can help these children by making the environment less trigger-y, and helping them learn how to calm themselves and to problem solve in difficult situations.
He advocates prioritizing rules into three baskets: the MUSTs, the we are working on its, and the never minds (he calls them A, B, and C). Safety is a must -- a parent or teacher will tolerate and manage a meltdown to prevent the child from hurting herself, others, destroying property, etc. The "working on its" evolve over time, and involve the kind of collaborative problem solving characteristic of Thomas Gordon's excellent _P.E.T.: Parent Effectiveness Training_. Everything else is a never mind (at least for now, but hopefully over time some of these can work their way into the working on it category, as everyone calms down and gets along better).
In a way, Greene is just advocating what every competent parent and teacher learns relatively quickly: you must choose your battles, and you must stay a couple steps ahead of the little ones. Reducing demands on children who cannot cope with multiple, incompatible, ambiguous demands is a matter of staying ahead of the little one: if you _know_ that too many rules at once will set the kid off, then you should also _know_ not to fucking do that again. If you are going to give in on a particular rule after a tantrum or meltdown, then you really might as well give in pre-emptively, so as to not teach the little one that tantrums get you stuff.
I feel bad for Greene, because he is clearly constantly up against it with all the Positive Parenting, Consequences, etc. approaches to "discipline". They all think he's too permissive and a wimp. Meanwhile, more radical parents will find Greene, like Gordon's _P.E.T._, inadequately respectful -- at least at times -- of children as people.
Greene has truly found an effective Sweet Spot in the business of teaching people how to better raise children, whether as parents, teachers, administrators, therapists or other. This is a book that everyone should read, even if you are not a parent, a teacher, work with children, etc. It can help us be more supportive friends of parents, teachers, etc. It can help us participate more usefully in setting public policy. It can even help us better understand ourselves, and other adults who have the kinds of cognitive, emotional and executive function problems which he describes in children.
While Greene touches upon autism/PDD, his approach is extremely verbal, which a problem. However, he does make an effort to simplify and clarify communication, which is not nothing. There are better authors for conveying the mechanics of communicating empathy. Finally, he really doesn't have any specific advice for ensuring safety when a child is violent, so his approach in the book is mostly aimed at children who are elementary school aged. The approach can absolutely work on larger/stronger/older people (and he has clearly applied it there), but that may be beyond the scope of what parents can manage so leaving it out of this book makes sense.