Yii is an open source, high performance PHP framework for developing web applications. It has been designed to work efficiently with the latest technologies and web standards. With its fast and secure architecture, Yii is a great choice for developing modern web applications. Its powerful features, such as Model-View-Controller (MVC), Object Relational Mapping (ORM), database access object (DAO) and query builder (Qb), make it easy to create modern, feature-rich applications quickly and effectively. Yii is a great choice for developers who want to quickly and efficiently build web applications that are secure, stable and performant.