Qhull is a general dimension code for computing convex hulls,
Delaunay triangulations, Voronoi vertices, furthest-site Voronoi vertices,
and halfspace intersections.
It appears to be the choice for higher-dimensional convex hull
applications.
Qhull is written in C, and
implements the divide-and-conquer Quickhull algorithm.
It is fast and
round-off errors from floating point
arithmetic.
Qhull has been widely used in scientific applications and has a
well-maintained
home page
.