Using Babel with a single output file and ES6 modules

You're not the first one with the need of transpiling JSX/ES6 to ES5 with Babel but without using CommonJS modules and hence Browserify/Webpack. Unfortunately it turns out this is not possible at the time (1, 2, 3), and it looks like it won't be possible ever. You're pretty much forced to use these tools if you want to use ES6 transpiled with Babel, but you won't have the chance to use the resulting code with other concatenated/inline JavaScript (because of all those require() calls rather than global variables on window). It's a pity Babel doesn't allow to change this behaviour.