MooTools

MooTools (My Object-Oriented Tools) is a lightweight, object-oriented JavaScript framework. It is released under the free, open-source MIT License.

Overview
MooTools provides the user with a number of options beyond native JavaScript. These include:
 * An extensible and modular framework allowing developers to choose their own customized combination of components.
 * MooTools follows object-oriented practices and the DRY principle.
 * An advanced effects component, with optimized transitions such as easing equations used by many Flash developers.
 * Enhancements to the DOM, enabling developers to easily add, modify, select, and delete DOM elements. Storing and retrieving information with Element storage is also supported.

The framework includes built-in functions for manipulation of CSS, DOM elements, native JavaScript objects, Ajax requests, DOM effects, and more. MooTools also provides a detailed, coherent application programming interface (API), as well as a custom downloads module allowing developers to download only the modules and dependencies they need for a particular app.

History
Valerio Proietti first authored the framework and released it in September 2006 taking as his inspiration Prototype and Dean Edward's base2. MooTools originated from Moo.fx, a popular JavaScript effects library released in October 2005 by Valerio Proietti as an add-on to the Prototype Javascript Framework. It can be used as a lighter alternative to script.aculo.us or other, bigger libraries. It provides simple, basic effects, and guarantees a small library size.

Whereas Prototype extended&mdash;prototyped&mdash;many of JavaScript's native String, Array, and Function objects with additional methods, Proietti desired a framework that (at the time) further extended the native Element object as well to offer greater control of the Document Object Model (DOM).

Components
MooTools includes a number of components, but not all need to be loaded for each application. Some of the component categories are:
 * Core: A collection of utility functions that all the other components require.
 * More: An official collection of add-ons that extend the Core and provide enhanced functionality.
 * Class: The base library for Class object instantiation.
 * Natives: A collection of JavaScript Native Object enhancements. The Natives add functionality, compatibility, and new methods that simplify coding.
 * Element: Contains a large number of enhancements and compatibility standardization to the HTML Element object.
 * Fx: An advanced effects-API to animate page elements.
 * Request: Includes XHR interface, Cookie, JSON, and HTML retrieval-specific tools for developers to exploit.
 * Window: Provides a cross-browser interface to client-specific information, such as the dimensions of the window.

Browser compatibility
MooTools is compatible and tested with:
 * Safari 3+
 * Internet Explorer 6+
 * Mozilla Firefox 2+
 * Opera 9+
 * Chrome 4+

Emphasis on modularity and reusability
Every JavaScript framework has its philosophy, and MooTools is interested in taking full advantage of the flexibility and power of JavaScript in a way that emphasizes greater modularity and code reuse. MooTools accomplishes these goals intuitively to a developer coming from a class-based inheritance language like Java with the MooTools Class object.

Class is an object of key/value pairs containing either properties or methods (functions). Class is effortlessly mixed and extended with other Class instantiations allowing for the most excellent focus of MooTools: Code reuse achieved through maximizing the power of JavaScript's prototypical inheritance but in a Class object syntax more familiar to classical inheritance models.

Object-oriented programming
MooTools contains a robust Class creation and inheritance system that resembles most classically based Object-oriented programming languages. For example, the following is MooTools' equivalent of the examples in Wikipedia's polymorphism page: