Surely complexity always creates risk. The question is whether the tradeoff is acceptable. Everyone is optimizing the hell out of their Javascript engines righ

Surely complexity always creates risk. The question is whether the tradeoff is acceptable. Everyone is optimizing the hell out of their Javascript engines right now -- the question is whether some jit that's cobbled together independently of any other codebase is going to be intrinsically superior to a compiler that's being used for lots of other things (obviously there are arguments in both directions, right?). Is it better to simultaneously support Javascript via V8 (which has tiered optimizations of its own), Dart both via compilation to Javascript and its own independently optimized runtime, and NaCl? Is it better to have Javascript and asm.js? Your trusty Apple II will be immune to modern malware thanks to the simplicity of not being able to connect to the internet, run 32-bit software, or have more than 48kB of memory. Of course the Apple II did have at least one virus.