An implementation of the Gilbert, Johnson, and Keerthi (GJK) algorithm for tracking the distance between a pair of convex polyhedra. Source available for nonprofit use.
An interactive and exact collision-detection library for convex polyhedra. Includes the source code (free for noncommercial use), relevant papers, and an MPEG demonstration.
A numerically robust library supporting general polygon soups, based on oriented bounding box (OBB) trees. The source is available for noncommercial use via email. A paper on OBB trees is available for download.
A collision detection library for general polygon soups. Combines I_COLLIDE's "sweep and prune" algorithm with RAPID. Source available for noncommercial use.