I have the third edition on my bookshelf and it has been a good reference. I think this book may be directed more
to people that have to implement Scheme than people learning it, e.g. there is a continuous reference to S5RS and ANSI Scheme differences [3rd edition]. At the end of the third edition there are solutions to selected exercises so it is good for checking some of your knowledge right away.
edit: Also, I’m waiting for “The Little Schemer” so I’ll be able to actually compare the two later
I am not trying to implement Scheme but I still find this book quite useful.
I had some experience with functional programming, and was most curious in the Scheme-specific stuff, like continuations, Scheme’s flavor of macros, use of tail recursions, etc. Scheme is also famous for its minimalism, so I would also like to get a feeling of how the builtin facilities are designed and structured.
I once read R6RS but found it a bit too abstract. I think this book actually covers more or less the same material as R6RS, and it’s probably fair to describe it as a pedagogical version of R6RS.
Chapters 1-3 give you a very succinct yet deep overview of the language, and also provides exercises for you to check your understanding. I would say chapters 2 and 3 remind me of K&R, although I certainly wish there were more exercises.
Chapters 4-11 of this book cover the builtin facilities. Again, it is like R6RS, but feels more pedagogical. I just finished chapter 3 so it’s just a general feeling.
Chapter 12, “extended examples” has been lauded by many. I haven’t dived into that chapter yet, but again it looks quite educational.
In summary, if you are in a similar situation like me - having some general experience with FP, wants to learn Scheme thoroughly, but find RnRS a bit too dense - this is the textbook I would recommend.
Is there a changelog?
If you mean a list of changes from the previous edition, I don’t think there is.