Voro++ is a software library for carrying out three-dimensional computations
of the Voronoi tessellation. A distinguishing feature of the Voro++ library
is that it carries out cell-based calculations, computing the Voronoi cell
for each particle individually. It is particularly well-suited for
applications that rely on cell-based statistics, where features of Voronoi
cells (eg. volume, centroid, number of faces) can be used to analyze a
system of particles.
WWW: http://math.lbl.gov/voro++/