Sencha
Welcome to the Ext JS 4.1 Beta!
Ext JS 4.1 is a pure JavaScript application framework that works everywhere from IE6 to the latest Chrome. It enables you to create the best cross-platform applications using nothing but a browser, and has a phenomenal API.
What’s New
We have also been posting summaries of new features and changes to our blog:
Upgrading
Check out our upgrade guide to see what has changed.
Sencha also offers training courses and professional services for companies wishing to use Ext JS 4.