Polymake is a versatile framework for experimental discrete geometry.
The standard distribution contains tool collections for the algorithmic
treatment of polytopes and polyhedra, polyhedral surfaces,
and finite simplicial complexes.
It offers an unified interface to a wide variety of algorithms
and free software packages from the computational geometry field,
such as convex hull computation or visualization tools.

Polymake is highly adaptable to individual needs.  In particular, it
has a C++/perl interface which allows the user to bind his/her own
algorithms into the common framework.

WWW: http://www.math.tu-berlin.de/polymake/