Wow, the Nanopass Compiler Framework used in the Chez Scheme compiler, which is the compiler that produces the fastest native binary programs of all Scheme implementations, is available as a separate library that you can use in any compiler.

> The nanopass framework provides a tool for writing compilers composed of several simple passes that operate over well-defined intermediate languages. The goal of this organization is both to simplify the understanding of each pass, because it is responsible for a single task, and to simplify the addition of new passes anywhere in the compiler.

(define-language L0
  (terminals
    (variable (x))
    (primitive (pr))
    (datum (d))
    (constant (c)))
  (Expr (e body)
    x
    pr
    c
    'd
    (begin e* ... e)
    (if e0 e1)
    (if e0 e1 e2)
    (lambda (x* ...) body* ... body)
    (let ([x* e*] ...) body* ... body)
    (letrec ([x* e*] ...) body* ... body)
    (e0 e1 ...)))