Ext4Yii is essentially a bridge between these two projects, which aims to integrate Ext JS as an extension for Yii. Ext4Yii is implemented as a templating system, which consumes XML models where you define widget elements like buttons or handlers (in embedded JavaScript code which can take advantage of Ext-powered methods and objects).

This templating system integrates directly with the Yii framework's structure and gives you access to a lot of the ExtJS objects without the need for multiple calls to .js files. The tool also comes with a bundled plugin for Netbeans that can help you get started quickly (rather than having to work out the syntax by hand from the start).