This keeps coming up lately and it really needs to be clarified. Asm.js is not a useful tool for running dynamic languages as a browser-replacement for js. It c

This keeps coming up lately and it really needs to be clarified. Asm.js is not a useful tool for running dynamic languages as a browser-replacement for js. It carves out its own heap and has extremely limited interaction with the DOM. You probably could establish a bytecode for that purpose, but the problem is that putting it at a higher level (where real interaction with the DOM is possible) gives you an impedance mismatch between object (how messages are dispatched) and execution models (how things like exceptions propagate) that can only be overcome at some degree of a performance loss. I'm not saying that can't be solved, but I don't think anyone's put any serious effort into doing so in a generalizable way.