SaneScript is AFAICT like the "use strict" directive in ES5 which defines a restricted subset of the language. Compilers might also take advantage of this by pe

SaneScript is AFAICT like the "use strict" directive in ES5 which defines a restricted subset of the language. Compilers might also take advantage of this by performing certain optimizations. SoundScript extends this restricted subset. It is incompatible with previous versions of JavaScript only in the same sense that ES5 is incompatible with ES3: It introduces new features not supported by older engines.