The following software is freely available to all interested parties. However, if you publish research using this software, I would appreciate a brief acknowledgement.
The Zeno software package is a comprehensive environment for N-body/SPH simulation and analysis in UNIX/LINUX. I am releasing the current LINUX version of the code. This software is offered `as is', and no warranty as to its performance can be made. I've received no support from funding agencies to develop this software, and I can't promise to answer questions about its use.
http://www.ifa.hawaii.edu/~barnes/software.html