"if you are targeting a specific platform you really should (completely imho) use the tools meant for it. Anything else will easily lead to issues that may not

"if you are targeting a specific platform you really should (completely imho) use the tools meant for it. Anything else will easily lead to issues that may not be debug-able if you aren't already familiar with your target." By that logic, since my processor doesn't natively run Ruby, I should be coding in machine language. I can't speak for CoffeeScript yet, but the front-end developer who sits near me is using SCSS to generate CSS for our web pages, and he is able to do things that wouldn't be practical with plain CSS. For example, change a base color variable from blue to green, and have all the other colors on the page adjust to use complementary colors. If you trust Ruby to produce reliable C code and C to produce reliable assembly code, etc, isn't it possible that Coffeescript could produce reliable Javascript? Mightn't it give you advantages like Ruby gives you over plain C? I think this is less a matter of "compiling X to Y is good/bad" than "do I trust this particular conversion to be done correctly?" As far as compiling Ruby to PHP - well, I can't see any use for that at the moment, but I'm sure someone will come up with one. :)