A library for drawing 2D primitive shapes in XNA. The library has methods for drawing pixels, lines, rectangles, filled rectangles, circles, and arcs. Development moved to: https://bitbucket.org/C3/2d-xna-primitives
A generic type QuadTree implementation in C# for use with XNA. This QuadTree can store any object that implements the interface IHasRectangle. This provides a means of accessing objects in a virtual space very quickly. Development moved to: https://bitbucket.org/C3/quadtree/
XFX or XNA For XBOX is an open-source implementation of the XNA framework for the XBOX1 console. It is built on top of OpenXDK, the legal XBOX Development kit.