My favourite editor is [Komodo Edit](http://www.activestate.com/komodo-edit "") (free and crossplatform) and I use it for my everyday coding work. Just recently I found out how to make it help me to work with Yii. :) So follow these steps:<br>
 
1. [Create](http://www.yiiframework.com/doc/guide/1.1/en/quickstart.first-app "creat webapp") your webapplication.<br> 2. Start Komodo Edit.<br> 3. Create new project.<br> 4. Open '`Project Properties and Settings'` (Project → Properties).<br> 5. In dialog that appears choose '`Directory and File Filters'` and specify your application folder (e.g. WebRoot/testdrive).<br> 6. In the same dialog choose `Languages->PHP` and add the path to your `yii/framework` folder by clicking add button.<br> And that's it. Now you can enjoy code completion and calltips for Yii classes, methods/functions.<br>
 
But I must give you two remarks:<br>
 
1. It takes time to parse all the Yii files and it may seem not to work at first. Be patient.<br> 2. Unless you remove `yiilite.php` from your  `yii/framework folder` in calltips you will see only function name with the list of its parameters. But if you do remove `yiilite.php` you'll be able to see much more information about the function.<br> Of course you must do it before step 6 above.
 
Hope my little article will be of some use for you.