Yii Software is a company focused on the development and maintenance of the Yii PHP Framework, an open-source, high-performance framework for developing web applications. Established with a strong emphasis on simplicity, scalability, and efficiency, Yii is designed to support rapid application development by providing a robust set of features, such as MVC architecture, built-in authentication, and sophisticated caching mechanisms. Yii's extensive documentation and active community make it a suitable choice for both beginners and experienced developers looking to create secure and professional-grade applications.