I'm a bit bemused by your comment. Given the conversations that jashkenas and Brendan Eich have had... I think it's pretty clear that CoffeeScript is an "impro

I'm a bit bemused by your comment. Given the conversations that jashkenas and Brendan Eich have had... I think it's pretty clear that CoffeeScript is an "improve on javascript" language quite explicitly. Interestingly, I think that quality is entirely orthogonal to production worthiness and any implied or explicitly stated guarantees about utility and unbreakiness. I've personally thrown my weight behind up and coming technologies in the past (Merb to be specific, back in the Merb vs Rails insurgency), and ended up supporting a technology stack that was left abandoned. In spite of that, my company continued running happily on Merb for 3 years after that (until a move to Scala). That jashkenas warns people with a "caveat emptor" doesn't mean a tool shouldn't be used in production. It means that you should carefully evaluate how you use your tools in production, make sure you write modular testable code, be willing to dive down into the weeds, and most importantly always have a backup plan. The interesting part about CoffeeScript is that the backup plan (again if you have properly factored code) can just be "use more Javascript". :P (my own caveat is that I do not CoffeeScript in production. At least, not yet.)