>To make such an airy assertion in an under-researched comment makes me suspect that you don't know that much about either PNaCl or "any browser". So why did you make that confident-sounding claim?
Unfortunately, I can evaluate technologies according only to my experience and knowledge. According to my limited knowledge and experience, what PNaCl evolves to seems like the way to go: I can use whatever language I like to write code; I can utilize resources of computers efficiently; The code is performed in a sandbox; It's based on non proprietary standards (I mean LLVM, not Pepper).

>The bit about "can be easily integrated into any browser" is false due to Pepper, the large new target runtime for *NaCl. Pepper is a non-standard and unspecified-except-by-C++-source plugin API abstracting over both the OS and WebKit -- now Blink -- internals.
It's a new technology, how is it supposed to be standardized? IMO, it's better to create some implementation,
and then, to standardize it, not vice versa. AFAIU, how Pepper API works, the application is run as a separate process, operating system APIs are isolated with Pepper API and there's a way to post JavaScript code to be executed in browser's event dispatch thread to update and query DOM. This API seems to be narrow and generic enough to be supported in any browser. Code which provides OS services can be reused from code as is, the only variable part is DOM interaction, which is narrow enough to be supported in any browser.

>Have you heard of ES4? Mozillans including yours truly poured years into it, based on the belief that programming-in-the-large required features going back to "JS2" in 1999 (designed by Waldemar Horwat), such as classes with fixed fields and bound methods, packages, etc.
I closely monitored what have been happening to Harmony, and it was obvious that this effort wouldn't have panned out. There were just too many complex features to be implemented (for example, generics) in a single release.

>These days, large apps are written in JS, even by hand. GWT is not growing much from what I can tell, compared to its salad days. Closure is used the most within Google, and Dart has yet to replace Google's use of GWT + Closure.
I myself write large scale JS apps with GWT. It's really painful but if it was written in plain JavaScript it would have been much worse (I think it event would have been impossible to write and debug code which I write). GWT has its disadvantages: compilation time is very slow, I don't have access to many APIs (mainly reflection and dynamic code loading), devmode for all browsers but Firefox is awfully slow. But despite its disadvantages, it's the best tool for my job (I debug most of the code in JVM, by abstracting away access to DOM).

Both Mozilla and Google agree on goodness of LLVM, since both PNaCl, and asm.js toolchain are based on it. Google has solved the problem of efficiently representing LLVM in a platform independent way and safely executing it in a sandboxed environment. Why not create a PNaCl and LLVM based standard to allow, efficient execution of code? Is it so difficult?

Mozilla promotes asm.js as a "standard compliant" way to do the same thing as PNaCl. However, there are a lot of disadvantages in this approach: asm.js is text based and very verbose, binary format will save a lot of traffic; asm.js doesn't provide access to SIMD and multi-threading which are crucial for good performance; asm.js won't work out of the box, it requiress some effort to support on the side of browser vendors, for example, the only browser where Unreal demo initially worked was Firefox nightly build. Is it so hard to find a consensus among browser vendors (or at least Mozilla and Google) in this respect?