I wonder if Sussman has come across Shen [1]?<p>It is a small Lisp based on Klambda,  comprised of just 43 instructions, that has been ported to Common Lisp (SBCL), Haskell, Ruby and Emacs Lisp (just this month). It has also been ported to Python, Clojure, Javascript, Java, and the JVM which are not up to Shen 19 certification yet.<p>Shen has pattern matching, an integrated fully functional Prolog, static type checking and even optional lazy evaluation. It has a very strong type system.<p>Shen commercial has Griffin, an optimized compiler, SML (Shen Markup Language) to generate HTML, and concurrency.<p>Popularity has not been my reason for selecting a language. I have been using J, an APL-derived, language for years, and I also like APL, K, and now Q! It is amusing to see developers rediscover APL concepts after 50 or more years!<p>[1]  <a href="http:&#x2F;&#x2F;shenlanguage.org&#x2F;" rel="nofollow">http:&#x2F;&#x2F;shenlanguage.org&#x2F;</a>
[2]  jsoftware.com