NaCl is just native machine code with some additional restrictions, AFAIK. It can make use of existing compilers and optimizers. I agree that the binary is pro

NaCl is just native machine code with some additional restrictions, AFAIK. It can make use of existing compilers and optimizers. I agree that the binary is probably relatively efficient, but a) only if your code deals with 32bit floating point numbers, b) the binary (erm js file) is probably going to be bigger (hence increased download times) c) the compilation does not come for free.