XFX, or [XNA](http://en.wikipedia.org/wiki/Microsoft_XNA) for [XBOX](http://en.wikipedia.org/wiki/Xbox_(console)) is an implementation of [XNA](http://en.wikipedia.org/wiki/Microsoft_XNA) 4.0, written in C++ for Microsofts [XBOX](http://en.wikipedia.org/wiki/Xbox_(console)) console.
It's written on top of [OpenXDK](http://sourceforge.net/projects/openxdk/), the open source, free, legal XBOX Development Kit.
XFX is an attempt to bring development for the original [XBOX](http://en.wikipedia.org/wiki/Xbox_(console)) console to the masses by wrapping all low-level code in the familiar XNA classes.
Being written in C++ allows XFX to be lightweight and as close to the hardware as possible.
Compiling XFX requires at least OpenXDK version 0.7