> asm.js is basically a "best practices" guide for js vm authors. No. It is a specifically designed subset of JS that also has extra annotations. If a block

> asm.js is basically a "best practices" guide for js vm authors. No. It is a specifically designed subset of JS that also has extra annotations. If a block of code does not adhere to the rules, it is not asm.js and will be processed as regular JS. If it validates, it is processed by a different compiler pipeline and AOT compiled. It is much more accurate to say that asm.js is a newly designed byte-code that very cleverly happens to use backward-compatible JS as its serialization. Native Dart is also not guaranteed to be faster than Dart2JS. > Dartium requires the end developer distribute 2 payloads, one for Dartium browsers and 1 for JavaScript browsers. Ah but that is only extra work for the developer. Similar to compile-to-JS languages like TypeScript, CoffeeScript, Emscripten, etc. there is no problem with new technologies that impose extra work on the developer, because it is the developer's choice to use it or not, so the person making the decision is the one paying the extra administrative cost.