Yii Wheels has been completely rebuilt from ground up. It differs from its predecessor, YiiBooster, in that widgets and their assets are isolated in their own folders; which promotes better and easier maintenance. YiiBooster had to register all its required assets at the once, and developers soon realized that this slowed things down, as compared to Yii-Bootstrap's performance. Now, with YiiWheels, you register only what you need, when you need it, nothing else, nothing more. Simple, but elegant.