The Attribute utility allows you to add attributes to any class through an augmentable Attribute interface. The interface adds get and set methods to your class to retrieve and store attribute values, as well as support for change events that can be used to listen for changes in attribute values.
Base is designed to be a low-level foundation class from which other attribute- and event target-based classes in the YUI library can be derived.
EventTarget is a core extension class that provides APIs for publishing, firing, and subscribing to custom events
Lightweight `Y.Attribute`-based data model with APIs for getting, setting, validating, and syncing attribute values to a persistence layer or server, as well as events for being notified of model changes.
Provides an API for working with an ordered list of models and for adding to, removing from, and sorting the list.
Plugins allow you to unobtrusively add functionality to objects (referred to as the "host" object), generally nodes and widgets.
Provides URL-based same-page routing using HTML5 history or the location hash.