MooTools is a compact, modular, Object-Oriented JavaScript framework designed for the intermediate to advanced JavaScript developer. It allows you to write powerful, flexible, and cross-browser code with its elegant, well documented, and coherent API. Mootools contains a robust Class creation and Inheritance system.
It is lightweight, powerful and makes use of many new JavaScript coding functions.
The rich FX library uses the same physics-easing-equations as most flash users. [more]