Of course we all can publish anything. I am talking about limitation of js npm modules, it have to be es5 only. What if we are ready and want publish and then use our es6..7..11111 modules ? Aha, we can compile it and provide appropriate module.exports mechanizm. Hm , looks like there is a problem. No there is at least two problems - provide commonjs build and provide source code of course. Stop , what about debugging, it not so cool debug compiled code, we need sourcemaps and something to read them.. .ah, idk .