Grails vs. Revel vs. Yii

Grails is a framework used to build web applications with the Groovy programming language. The core framework is very extensible and there are numerous plugins available that provide easy integration of add-on features.

Revel makes it easy to build web applications using the Model-View-Controller (MVC) pattern by relying on conventions that require a certain structure in your application. In return, it is very light on configuration and enables an extremely fast development cycle.

Yii comes with: MVC, DAO/ActiveRecord, I18N/L10N, caching, authentication and role-based access control, scaffolding, testing, etc. It can reduce your development time significantly.