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.

LGPL standard C++ library for interactive collision detection, based on axis-aligned bounding box trees.

An implementation of the Lin-Canny algorithm for computing the distance between two closed polyhedra. Source available for noncommercial use.

A collision detection library for general polygon soups. Combines I_COLLIDE's "sweep and prune" algorithm with RAPID. Source available for noncommercial use.