Your point is irrelevant, then difference then becomes the fact that at an OS level I can choose what code I compile into machine code and in the browser I can't.
No, for OS you decide which compilator to choose. As is with browsers. There are several languages (e.g. TypeScript, CoffeeScript, Dart) which can be compiled to JS.
That is not what I personally like (the processes of compilation and deployment I mean), but if you develop for OS then you have to compile before you run... In most OS.
> Your point is irrelevant, then difference then becomes the fact that at an OS level I can choose what code I compile into machine code and in the browser I can't.
Uh, what? You do have a choice in the browser. I don't understand.
No, it doesn't work on OSes. OSes only handle one language: the native machine code of that platform. Everything else must be compiled to it.
This is exactly the same as browsers.
Edit: At least two people disagree with me (-1 points) - would you mind elaborating why?