From jQuery JavaScript Library

• jQuery Enchant effects suite now part of jQuery UI
  • Can be used standalone without UI core
  • Extends the native jQuery API
  • Advanced easing functions
  • Class transitions (morphing): $("div").addClass("green", "slow")
  • Color animations: Accepts hex, rgb and names
  • more than 16 stand-alone effects
    • everything known from script.aculo.us, but highly configurable (blind,bounce,drop,fold,slide,puff ..)
    • brand-new effects: transfer, explode, clip, scale
• New meta structure
  • Brand-new homepage, redefined logo
    • Design by Liferay art director Brian Miller
    • Download builder
    • Real-world and functional demos
  • ThemeRoller
    • Rich theming application by Filament Group
    • Create and share your own UI themes
    • Download and bundle them with the UI widgets
  • New bugtracker and SVN project
    • Dedicated bugtracker with version targeting and categories on http://ui.jquery.com/bugs
    • Dedicated project on google code, restructured and cleaner SVN trunk and branches (http://code.google.com/p/jquery-ui)
• New features and API changes
  • Hundreds of bugfixes, enhancements and performance improvements with many components completely rewritten
  • Unified API for all plugins (see http://jquery.com/blog/2008/02/12/jquery-ui-15b-new-api-more-features-huge-performance-boost/)
  • New unit tests using a UI event-testing plugin called simulate
  • Exposed defaults for every plugin
  • Retrieve and change individual options during plugin runtime
  • Intelligent plugin cleanup on remove() calls
  • Easier file structure, fewer dependencies
    • jquery.dimensions.js now part of jQuery itself
    • removed the need for *.ext.js files and ui.mouse.js, added a global ui.core.js
  • Datepicker
    • Countless new translations
    • Support for right-to-left languages
    • Enhanced date formatting
    • Many new options: showWeeks, calculateWeek, showAnim, onClose and more
    • Added status bar
    • Now allows control characters to be typed (copy/paste)
  • Dialog
    • Added stack option (bring dialog to front of other dialogs when given focus)
    • Extended resizable option to accept a list of handles
    • Added modal dialogs (modal/overlay options)
    • Added closeOnEscape option (pressing escape while the dialog has focus will close the dialog)
    • Added bgiframe option (applies bgiframe to dialog; requires bgiframe plugin)
    • Better position support
    • Added autoOpen option
  • Draggable
    • non-destrutive drag & drop: can handle fixed, absolute and relative positioned elements, and keeps the setting
    • better option naming: preventionTimeout becomes delay, preventionDistance becomes distance
    • new feature: snapping (snap to other elements, like the Winamp windows)
    • new feature: stack control - let the plugin automatically handle z-indexes
    • new feature: connectToSortable: allows dragging the draggable into a sortable list
  • Resizable
    • Added default theme support if the theme is not loaded
    • Support for canvas element
    • Added preventDefault (prevent native browser resize - safari)
    • Added transparent handles option
    • Added knobHandles (option to simulate image cropper styles on the handles)
    • Added grid option (resize on a grid)
    • Added animate option (animated resizing)
    • Added ghost option (creates a ghost of the element while resizing)
    • Added containment option (resize inside a limited area)
  • Accordion
    • Renamed option autoheight to autoHeight and changed the default to true
    • Autocreate additional elements required for theme when ui-accordion class isn't present on container element
    • Enhanced navigation-option by adding navigationFilter-option, accepting a custom filter to find the active panel
    • Reduced flexibility in terms of markup, in favor of much smoother animations: There must be exactly one content panel for each header
  • Selectable
    • Added start and stop callbacks
    • Improved hit detection so lasso selects item instead of mouse
    • Added autoRefresh option. default: true
    • Added manual refresh method (to be used with autoRefresh: false)
    • Added appendTo option
  • Slider
    • new feature: ranges and multiple handles
    • huge accessibility improvements: keyboard control, focussing individual handles
    • new logic: clicking or dragging somewhere other than a handle starts dragging the focussed handle
    • can generate handles now, with every handle having it's individual max/min option
    • new-feature: dual-axis slider, allowing do create widgets like colorpickers
  • Sortable
    • Rich interconnectivity
      • Connect multiple sortables and allow sorting two-way or one-way
      • Serialize sorting results to a url string or to arrays
      • Drag draggables into sortable lists, drop sortable items on droppables
    • Improved tolerance
      • Three tolerance modes: "intersect", "pointer" and "guess", defaults to "guess"
      • Now works for all kinds of different sized elements
    • Adds much of the draggable functionality: cursor, zIndex, revert, opacity, axis, handles, containment and scrolling
    • Introduces more callbacks: over/out, activate/deactivate and remove/receive
    • Better control the placeholder: insert object with element and update callbacks to do what you want
  • Tabs
    • all things zero-based for consistency
    • show callback is now called on initialization
    • set selected tab via selected option
    • set all tabs unselected via selected: null instead of another redundant option
    • simplified effects options - one fx option (which mirrors jQuery’s default animate options) instead of a bunch of others to remember.