I love the idea of Reason/ReScript. I hope they can figure out a way to work together and join forces somehow, the contributions to both repos seems to have faded over the last years, but maybe that's because the projects have stabilized, I don't know.

I've had lots of fun playing with Reason a few years ago. I created an interactive real-time visualization tool, to see a Regexp transform into a NFA to DFA to minimal DFA graph: http://compiler.org/reason-re-nfa/src/index.html It only works for basic regexes though.

The ReasonML workflow continued on as Melange.

https://melange.re

I can’t speak for Reason but the ReScript project and community is very alive and vibrant. There’s been some major improvements over the past year and overall it’s much more appealing and mature now compared with only a few years ago. We’ve been using it in a fairly large React app for a while and the experience has been very good.