The following things are newly added in Yii version 2.0 :
* The Yii 2.0 framework supports PSR-4 class autoloading, simpler namespaces, faster loading, and improved usability for developers.
* The Yii 2.0 framework added performance and security improvements.
* The Yii 2.0 framework added RESTful API integration.
* The Yii 2.0 framework added improvement on URL handling and processing.
* Now Yii 2.0 framework, Translations of core messages available in 26 languages.
