Nitpick: asm.js is designed for AOT, not JIT, compilation. A good browser will AOT asm.js, not JIT it. (In other words: pre-compiled, not compiled on the fly.

Nitpick: asm.js is designed for AOT, not JIT, compilation. A good browser will AOT asm.js, not JIT it. (In other words: pre-compiled, not compiled on the fly. Consequence: immediately as fast as a JIT would have… eventually… made it, but initial pause while compiling.)