You might also want to have a look at Julia. It's not really a lisp, but it sits on top of a scheme - and it has a rather interesting, pragmatic type system: "

You might also want to have a look at Julia. It's not really a lisp, but it sits on top of a scheme - and it has a rather interesting, pragmatic type system: "Julia: to lisp or not to lisp?": https://www.youtube.com/watch?v=dK3zRXhrFZY https://www.youtube.com/watch?v=dK3zRXhrFZY https://julialang.org/ https://julialang.org/ Maybe compare and contrast with Maxima?: http://maxima.sourceforge.net/ http://maxima.sourceforge.net/