PyParticles is an opensource particles simulation tool box entirely written in python.
It support the most popular integrations methods and the most relevant forces model. It also offer a nice looking OpneGL interface or at your preference a Matplotlib based GUI.
PyParticles as a forces models implements Gravity, spring, constant force and electrostatic and the user defined vector field force.
As a integrations method it includes Euler, Midpoint, Runge Kutta, Störmer Verlet and Leap frog.
With PyParticles you can freely combine every force model with all integration method in an easier as possible manner, for example you can change the integration method by switching a single line of code:
For example with this single line of code we can say to PyParticle to use the Runge Kutta method for simulating the model.
solver = rks.RungeKuttaSolver( grav , pset , dt )
The two following screenshots represents a simulation of the solar system and a set of 1000 random particles:

