Module 550 in TOMSPROPS and SRFINT: Fortran subroutines for computing surface area, centroid, volume, weight, moments, and products of inertia of solid polyhedra. The routines operate directly on geometric definitions consisting of vertex coordinates and face lists, in a format similar to that employed in graphics programs (See A.M. Messner and G.Q. Taylor, ACM TOMS 6 (1980) pp. 121-130.).