JavaScript is a beautiful programming language, the de facto client side scripting language of the web until something new comes along, which I don’t think will ever happen. It’s extremely elastic in that one can create user defined methods to use with built in objects like Functions, Arrays and even generic objects. It exposes DOM and HTML interfaces that one can extend as per the requirements of the web app they’re building.

It is so flexible that features not available in certain browsers, due to poor implementations of W3 standards or a complete disregard of their recommendations, could be added dynamically by writing JavaScript code that fills in those gaps, usually referred to as shims or polyfills. However, with this kind of malleability, it is also possible to overwrite built-in objects references.