Condensed in a single ~65KB file, F3 (as we fondly call it) gives you solid foundation, a mature code base, and a no-nonsense approach to writing Web applications. Under the hood is an easy-to-use Web development tool kit, a high-performance URL routing and cache engine, built-in code highlighting, and support for multilingual applications. It's lightweight, easy-to-use, and fast. Most of all, it doesn't get in your way.