AFAICT it did not start in html/js. it's C or C++ with lua. it exports to all kinds of formats including native executables for windows/Linux/Mac/iOS/android as

AFAICT it did not start in html/js. it's C or C++ with lua. it exports to all kinds of formats including native executables for windows/Linux/Mac/iOS/android as well as html/js. the js impl uses asm.js