Futhark is pretty great! And I have to say that the maintainer is insanely quick. It has happened on more than one occasion that I reported a bug and it's solved within the day. I have been using Futhark in prod for two years now and never had serious problems.
Interesting, what do use it for if you can share?
Optimization algorithms. The build in automatic differentiation is great!.
What is your use case?