FuelPHP is an open source web application framework written in PHP which implements the HMVC pattern. Developed by iKreativ.com
License: Open Source
FuelPHP is a lightweight and modular PHP framework that is easy to learn and suitable for smaller applications, while Yii Framework is a more robust and feature-rich framework designed for complex enterprise-level applications. Yii offers extensive built-in features but comes with a steeper learning curve compared to the simpler FuelPHP.