R6RS was basically DOA, with only 3 or 4 implementers (Guile, Ikarus, Ypsilon, and (partially) Racket) actually going along with it. Most of the other implementers, most notably CHICKEN&#x27;s Felix Winkelman, refused. R7RS is now split into a small core, and a large standard library for practical, as opposed to teaching, use, whose development STILL isn&#x27;t done.