Yii helps Web developers build complex applications and deliver them on-time.\r\n\r\nYii is pronounced as Yee or [ji:], and is an acroynym for \"Yes It Is!\". This is often the accurate, and most concise response to inquires from those new to Yii: \r\nIs it fast? ... Is it secure? ... Is it professional? ... Is it right for my next project? ... Yes, it is!\r\n\r\nYii is a free, open-source Web application development framework written in PHP5 that promotes clean, DRY design and encourages rapid development. It works to streamline your application development and helps to ensure an extremely efficient, extensible, and maintainable end product.\r\n\r\nBeing extremely performance optimized, Yii is a perfect choice for any sized project. However, it has been built with sophisticated, enterprise applications in mind. You have full control over the configuration from head-to-toe (presentation-to-persistence) to conform to your enterprise development guidelines. It comes packaged with tools to help test and debug your application, and has clear and comprehensive documentation.