Yahoo User Interface Library

 A collection of HTML, CSS, and JavaScript components for creating AJAX web
 pages. The library currently includes:
 .
  * utility classes for animation, browser history, AJAX, cookies,
    drag and drop. safe cross-site data retrieval, dynamic script/css loading,
    image loading, selectors, JSON, resizing elements, DOM and browser events.
  * Autocomplete, button, calendar, carousel, charts, color picker,
    data table, file upload, image crop, menu, paginator, layout manager,
    rich text editor, slider, tabview and treeview controls and a container
    control that can be used for tooltips, panels, dialog boxes etc.
  * A logging framework.
  * A profiler
  * A test framework
  * Cascading stylesheets for browser-independent grids and fonts.