fat-free一个php5.3的框架

http://fatfree.sourceforge.net/

FAT-FREE is a powerful yet lightweight PHP 5.3+ Web development framework designed to help you build dynamic and robust applications - fast!
Condensed in a single 55KB file, the framework's simple domain-specific language gives you access to Fat-Free's all-purpose template engine, flexible cache, automatic spam protection, integrated unit testing tools, and code profiler. It's so small and fast - it even has a bandwidth throttle for controlling Web server traffic. It's also the only framework that shields you from bandwidth theft and Denial-of-Service (DoS) attacks.

就一个core文件，其它都继承它？
好多错误提示。