First off, I do like HAML and I don't really like CoffeeScript (anymore), but thats not the point. What I see here is exactly what I've read in a rather old bo

First off, I do like HAML and I don't really like CoffeeScript (anymore), but thats not the point. What I see here is exactly what I've read in a rather old book (might've been the mythical man month, but not sure): There'll always be those people who don't care to wrap their heads around new ideas, because in their eyes they don't have an advantage. E.g. in the early days, assembly developer could not see an advantage in using a higher-level language such as C (:D), and when FORTRAN eventually came around, C programmers didn't really want to use that either. Why? Because if you spent time and energy on becoming proficient in something, be it assembly or javascript, the defensive but natural position of most people is to be skeptical of new ideas, because they diminish the value of their knowledge. If you're an expert in writing OO-code in JavaScript, and suddenly CoffeeScript comes around and lets everyone write "class" and be done with it, your JavaScript OO knowledge becomes less valuable. Bottom line, I can hardly imagine anyone who'd be able to learn CSS, JavaScript, HTML and perhaps another backend language, including all the quirks and weirdness associated with these technologies, and then _not_ be able to wrap their heads around e.g. HAML, if presented with proper guidance. The same goes for CoffeeScript, even if the learning curve might be a little steeper than for HAML. So are these specific technologies good ideas? I'd definitely say "yes" for HAML, and "don't know" for CoffeeScript (TypeScript perhaps?)... For both technologies, I agree with lucisferre: > 2. Both offer non-trivial gains in terms readability of the written code. > 3. Both can make future change of code non-trivially easier