jQuery 1.4 was released last week through a different site than the official jQuery site. jQuery, the most popular JavaScript framework on the web's new release have lots of changes specially in The code base has been heavily restructured to reduce complexity and increase performance. A substantial number of new methods and two new events: " focusin" and "focusout" have been added now.

With this new releaase, jQuery now passes on 100% of all tests in IE6, IE7, IE8, Firefox 2, Firefox 3, Firefox 3.5, Safari 3.2, Safari 4, Opera 10.10, and Chrome. Many bugs in previous versions have been fixed. I recommend you to see the documentation and other things related to new version from official site.