Hairlip: A very very tiny mustache-like thing.

hairlip.js

// Hairlip is 
// a very tiny version of mustache that only does variable replacement
// and nothing else.
String.prototype.hairlip = function (o) {
    "use strict";
    return this.replace(/\{\{([a-zA-Z0-9_\-]*)\}\}/g, function (a, b) {
        /*jslint unparam:true*/
        return {
            string: true,
            number: true
        }[typeof o[b]] ? o[b] : "";
    });
};