
This will become the new standard reference for people wanting to know about the Lisp family of languages.
But they also felt kind of detached from realities of industrial languages and compilers.
These days Crafting Interpreters is probably the best suggestion.
The Tiger book (with C, Standard ML, and Java variants)
https://www.cs.princeton.edu/~appel/modern/
Compiler Design in C (freely available nowadays, beware this is between K&R C and C89)
lcc, A Retargetable Compiler for ANSI C
Or if one wants to go with more clever stuff,
Compiling with Continuations
Lisp in Small Pieces
It takes a very thoughtful approach to introducing an increasingly complex Scheme implementation. I doesn't shy away from the complexity that many LISP implementation tutorials try to push under the rug.