[hga]

There have been plenty of practical applications for this stuff, just not directly in Lisp. Haskell and the ML family have interesting stories to tell; learning ML is on my list simply so that I can understand a lot of this research.

Yes, Lisp is the One True Way, but that doesn't mean it's the source of all good ideas in CS.

[lispm]

I'm talking about this specific Lisp dialect (from Sequent Calculus Research over Qi to Shen). It has near zero applications in 30 years.

I would not know why I would write anything I have written in the past in Scheme or Lisp, in this language and would it give me as advantage. The basic application seems to be programming language research and education.

True, many programming languages have applications, but for this I don't know any...

Common Lisp has a lot of applications in possible areas, for example that are a dozen theorem provers from PVS (used by NASA for example) to ACL2 written in Lisp. I'm not aware of a system remotely similar in Shen (or Qi) that's used by people.

[hga]

Two arguments here are that:

  1. Qi/Shen are very young, less than 10 years old.
  2. Their adoption has been crippled by wonky licenses.

That said, the sequent calculus can be viewed as an implementation detail, I don't believe it's integral to the use of Shen. There are arguments for adding features from non-Lisp functional languages, which I'll note in the forms of OCaml, F# and Haskell are seeing real world use.

I'll come back to this question after learning Shen (the wonky license has kept me from more than dipping my toe into it).