[ultrarunner]

I'm building a trial balloon in Crystal right now, though not Amber or Lucky. They had their 1.0 release (1.15, even), but it does not feel ready for production. The documentation is not great, the gotchas are unintuitive, and the discussion feels like they're not sure what direction to take the language. The runtime (event loop, fiber scheduler, and garbage collector) dependency means there's plenty of "magic" involved, making it feel significantly more like a framework than a language. Maybe that makes sense if they're targeting the web. If you're on the fence about choosing an established framework like Rails, though, Crystal is not the direction to go yet.