JSPAM: A restricted three-body code for simulating interacting galaxies
  Restricted three-body codes have a proven ability to recreate much of the
disturbed morphology of actual interacting galaxies. As more sophisticated
n-body models were developed and computer speed increased, restricted
three-body codes fell out of favor. However, their supporting role for
performing wide searches of parameter space when fitting orbits to real systems
demonstrates a continuing need for their use. Here we present the model and
algorithm used in the JSPAM code. A precursor of this code was originally
described in 1990, and was called SPAM. We have recently updated the software
with an alternate potential and a treatment of dynamical friction to more
closely mimic the results from n-body tree codes. The code is released publicly
for use under the terms of the Academic Free License (AFL) v.3.0 and has been
added to the Astrophysics Source Code Library.
