When you say NPAPI (now deprecated) you refer to a very wide spectrum of API's for very different problems. One such API under the NPAPI umbrella is NaCl/PNaCl

When you say NPAPI (now deprecated) you refer to a very wide spectrum of API's for very different problems. One such API under the NPAPI umbrella is NaCl/PNaCl which attempts to solve the problem of performance by allowing developers to use existing native C/C++ code by compiling it to a portable bytecode format based on LLVM, this is compiled ahead of time, achieving the same performance as traditional native execution in C/C++ (something that has be packing a boner 24/7). This code can be compiled to run on any platform in the case of PNaCl (NaCl is on it's way out anyway) and suffers a nominal performance penalty that is only felt up-front, not during execution. Alas all good things must come to an end, as Mozilla rejects this outright and chastises google for their anti-web-progress ways and their secret JavaScript assassination plots. The net effect is a whole lot of naysaying and bitching leading to the inevitable deprecation of PNaCl, though this will take a while since certain industries like gaming (NVidia) use it heavily and rely upon it to deliver high performance gaming on the web. Mozilla's attempt to solve this problem and their answer for PNaCl was/is ASM.JS which accomplishes a fraction of the performance gain, but does allow for semi-efficient porting of C/C++ code-bases to this esoteric form of JavaScript, which runs as a VM written in JS which is running in a VM......... Both technologies allow for any code that can be LLVM'd to be ported to the web with at least decent performance - and both are secure methods (PNaCl achieves security with it's double sandbox design and a strict hands-off-no-touchy the dancer rule). Both of these technologies share one final thing in common: they recently have been slated for certain deprecation in light of a new standard that Google and Mozilla actually agree on - they call this unicorn "WebAssembly" and it has just recently (like a few hours ago) been officially announced so it's a ways off. IE would then be forced to jump on the bandwagon, which may take them awhile though they are getting much better about keeping a positive attitude when swallowing Google's formidable load. Perhaps out of survival... Anyway, I look forward to this as it should bring similar performance to that found in PNaCl but with a standards based approach that is more "Web friendly" like ASM.JS - but I am now I am way off-topic and not sure what I am talking about anymore. Your speculation that we are in for interesting times ahead of unwarranted, we have been in interesting times for at least a few years in which all of the things you described are certainly possible but few developers existed with the skills, time, funding, or incentive to do so. It has only taken this long for Firefox to catch up to Google's ridiculous momentum so that such tools could be made for an acceptable portion of browser market-share that the industry would be able really sink their sharp teeth into and not stay up all night worrying about profits and if Timmy's grandmother will finally listen to him and allow her browser to update.