The FFI with JavaScript is nice. Have a look at this paper, in particular the examples that can be copy-pasted to https://try.gambitscheme.org:
https://www-labs.iro.umontreal.ca/~feeley/papers/BelangerFee...
https://www-labs.iro.umontreal.ca/~feeley/papers/BelangerFee...
> (module-whitelist-add! '(github.com/feeley))
> (import (github.com/feeley/roman demo))
This paper might be helpful if you want to know why it was designed that way:https://www.iro.umontreal.ca/~feeley/papers/HamelFeeleyELS20...