From my perspective, the jam was 20 entries, from the forum post:
1/4
Lua with the flexibility of a lisp syntax and macro system.
1/4 clojure
1/4 The host guile scheme
1/4 chicken scheme + misc e.g. kawa scheme
Which I guess is a founder-effected version of wikipedia’s explanation of lisp given the small number of entries:
Today, the best-known general-purpose Lisp dialects are Common Lisp, Scheme, Racket, and Clojure.
I guess having a sense of incommensurability is on brand for lisp.