xSGE Physics Frameworkhttp://xsge.nongnu.org
xSGE is a collection of extensions for the SGE licensed under the GNU
General Public License. They are designed to give additional features
to free/libre software games which aren't necessary, but are nice to
xSGE extensions are not dependent on any particular SGE implementation.
They should work with any implementation that follows the specification.
This extension provides an easy-to-use framework for collision physics.
This is especially useful for platformers, though it can also be useful
for other types of games.