It won't do anything for non-Firefox users: things will just work, which is pretty much the entire point and a pretty huge difference from (P)NaCl and Flash. a

It won't do anything for non-Firefox users: things will just work, which is pretty much the entire point and a pretty huge difference from (P)NaCl and Flash. asm.js is nothing but a "hint" to the JS engine that some optimizations are possible. IIRC, Chrome hasn't implemented support for the pragma because they believe they can get the majority of the benefits by making V8 smarter.