(For what it's worth, Persona looks promising to me personally, and I also like Rust very much, a lot more than Go. I say this to demonstrate that I'm not just a Google partisan and that I admire a lot of what comes from Mozilla).
I am much happier to discuss this dispassionately on a technical basis. I'm much happier if I don't have to argue against what to me are very unfair accusations, like being as proprietary as Silverlight.
> Here's a final clue: all browser vendors, definitely including Chrome, make the rule (not an argument) "no one gets to the machine except through our VM(s) and GC(s)"
I don't understand the argument you are making, (P)NaCl are specifically designed to allow execution of untrusted code without making it run on top of a VM or GC. And (P)NaCl executables are OS-independent. I don't understand what you're getting at here.