Real-world scenarios

I'm closing this tutorial with a few examples which hopefully demonstrate that λanguage could be a better language than EcmaScript 5. I know, ES6 is just around the corner, but I don't think it's reasonable to expect widespread support in the next N years — for the time being, our choices are to either write a successful browser which provides an alternative to JavaScript (probability zero) or to compile a better language to JavaScript (success chance: 100%, if you're not a fast as hell monkey).