Can someone ELI5 what asm.js is? I've tried Googling it multiple times now and every time I basically give up because I can't relate to anything it's talking about when all they use is buzzwords.
A language which is a strict subset of JavaScript. The purpose is to write compilers from C to asm.js, which then allows you to write C code and it compiles to something that can run on the browser
... and that strict subset of JS can be compiled into very efficient native code.