VPNBody: A symplectic solar-system integration package for VPython.

VPNBody (Visual Python $N$-body) is a collection of Python modules that uses symplectic integration algorithms to animate self-gravitating systems consisting of a gravitationally dominant object (a star) and several smaller objects (planets). VPNBody is primarily an educational tool. Animations can be used for classroom demonstrations, homework problems, and laboratory exercises. The underlying code can be used in upper-level physics and astronomy courses to introduce students to solar-system dynamics, or as a prototype for C or Fortran-90 software packages. This talk will focus on how the program works and several possible uses in the introductory astronomy and physics classrooms.