REBOUND is a new multi-purpose N-body code which is freely available under an open-source license. It was designed for collisional dynamics such as planetary rings but can also solve the classical N-body problem. It is described in a paper @ http://arxiv.org/pdf/1110.4876v2.pdf
Find it @ https://pypi.python.org/pypi/rebound/0.2.2
Find it @ https://pypi.python.org/pypi/rebound/0.2.2