Excellent, though I fear it might be a bit too late to seriously challenge Clojure+core.typed and/or lesser degree Typed Racket. Of course Shen's type system is

Excellent, though I fear it might be a bit too late to seriously challenge Clojure+core.typed and/or lesser degree Typed Racket. Of course Shen's type system is much more powerful, but that's probably not going to drive adoption as much as us typeful-programming weenies would like. Of course having multiple implementations running on multiple underlying platforms could turn out to be a killer feature...