Now browse to the Unreal Engine HTML5 website. It’s running their Epic Citadel demo, so you can walk through a citadel with gorgeous views, birds flying, reflections coming off inside floors and flags flapping outside. And just take a look at the flowing water. It’ll take a while to load — it’s packing 50 MB of data — but it’s well worth the wait.
I see this as a threat to Chrome with its Native Client plugin. That’s a way to compile C/C++ and other languages to run safely in Chrome and execute native code within the Chrome Browser. But so far no other browser maker has bought into it.
So why is asm.js so fast?
The Secret of asm.js
Altogether, these and other techniques yield execution performance up to half the speed of native code, and do it running safely in your browser. It’s not hard to consider that maybe this is the Holy Grail of developing fast Web applications. But, oh the irony! Just recompile old C/C++ source code! Some games libraries have already been converted.