April 11, 2013 V7.0 of epi_int, which is my N-body integrator designed to simulate self-gravitating planetary rings. For details, see my 2013 paper on this code, which is presently in review at Astrophysical Journal. To execute, start IDL and execute @epi_int.pro. To configure your simulation, edit the input parameters in inputs.pro. The code is heavily commented, consult them for further guidance. Execute @results.pro to view the output. Send suggestions or questions to: Joe Hahn jhahn@spacescience.org