Absolutely. Two languages that anybody who wants to truly understand computing, programming languages, and compilers are Lisp and Forth.

- Lisp is a fundamental, extensible, simple, unbounded AST system (and brings in interesting lambda calculus).

- Forth is a fundamental, extensible, simple, unbounded expression evaluator.

From there, the world is yours.

(Note I use "simple" in Rich Hickey's sense of simple vs easy)