[azakai]

> In a wondrous hypothetical future where processors support a NaCL restricted operating mode

If we speculate wildly, why not an "asm.js restricted operating mode"? Not saying that's a good idea, but I'm not sure why a NaCl one would be either. Both PNaCl and asm.js should reach pretty much native speed anyhow.

Btw, the L is not capitalized in NaCl.

[pbsdp]

> If we speculate wildly, why not an "asm.js restricted operating mode"?

Because we already had Jazelle, and it sucked, and we learned our lesson. A Jazelle that operates on ASCII-encoded bytecode with traps for unsupported JS constructs? No thanks. :)

> Not saying that's a good idea, but I'm not sure why a NaCl one would be either. Both PNaCl and asm.js should reach pretty much native speed anyhow.

Pretty much native and actually native are very different things.

I've had to sit down and hand-optimize critical paths that would not have been viable otherwise, and would have meant discarding a feature, or introducing a significant impact on usability -- and that's on platforms where similar investments in runtime library optimization were already made by the platform vendor, too.

If we're going to throw away performance, it has to be for a good reason. As someone who doesn't spend all day on platform development (as interesting as it might be), my focus is in providing the best possible user experience.

I'd love to do that on the web, but the web needs to punting throwing away solid technology decisions because of the bad technology decisions made in the early 90s when none of us knew what the hell we were doing.

> Btw, the L is not capitalized in NaCl.

Whoops. Thanks. Now I will look less stupid in front of software engineers AND my chemistry buddies. :)

[azakai]

> If we're going to throw away performance, it has to be for a good reason

I agree.

We are losing performance in return for: portability, security and standardization. The web runs everywhere, has a good outlook for continuing to do so (no fat binaries of current archs), and anyone can build a new web browser based on standards.

None of the other options proposed give us portability, secutiy and standardization right now. Perhaps with more work they might, and perhaps JS VMs will get closer to their speed as well. It's good to try to from both sides to improve things, and people are doing so.

I don't think anyone is overlooking some obvious better solution - that fits the requirements - that is before us. PNaCl (NaCl is not portable, so not relevant here) is interesting, just like the JVM and CLR, but they have major hurdles to pass if they want to be standardized, and that effort has not even begun in the case of PNaCl.