One of the new features in the release is that the functions in version 3.0 are now held in a stand-alone library, Ext Core 3.0, along with the HTML element animation functions. The lightweight library contains no UI components of any kind and, because of its size and range of functions, can now be considered as an alternative to jQuery.
As with the stand-alone library, Ext Core is available under a permissive MIT licence, which means it can be used freely in commercial projects. On the other hand, using the full version of Ext JS in commercial projects requires the purchase of a commercial license. Alternatively applications can be published under the GNU General Public License version 3 (GPLv3), which frees the full version from any usage charges. Ext JS 3.0 supports Internet Explorer 6+, Firefox 1.5+, Safari 3+, Opera 9+ and Chrome.