I'm surprised the author doesn't mention LISP, despite recognizing at some point that programming also IS language design (without explicitly calling it meta-li

I'm surprised the author doesn't mention LISP, despite recognizing at some point that programming also IS language design (without explicitly calling it meta-linguistic abstraction, unlike SICP). LISP is the language/notation most easily/flexibly extended, and this is one of the reasons why it may never disappear as long as we still have programming languages around.