These are various programs I have written over the last several years. Download them, try them out, use them, give some feedback. MacRay is a general purpose two-dimensional seismic ray-tracer for Macintosh. Originally written to trace rays through 2-dimensional p-wave models, MacRay has grown to support 2-d models defined in Vp, Vs and density. In addition to being able to model the full range of simple to complex raypaths, the 2-d gravity response of the model may also be calculated. For surveys providing seismic P, S and converted wave arrivals in addition to gravity measurements, the full suite of physical properties may be modeled; Vp, Vs, density, Poisson's ratio, Vp/Vs, Shear modulus, Bulk modulus, Young's modulus, Lame's parameter, lithostatic pressure. With the addition of an assumed or measured geothermal gradient, we can model the pressure and temperature conditions at any point in our earth model. A recent addition to MacRay allows you to define the features of a pressure-temperature diagram (e.g. metamorphic grade, solidus) and map those P-T regions back into the earth model. AT LAST!!! Thanks to the porting efforts of Larry Baker, MacRay for OSX is ready. This version also runs on the Intel Macs. If you cannot avoid using a PC, RAY84PC is a PC version of the old Ray84 I wrote for Vax many, many years ago. It was ported from Vax -> PC by Hans Thybo of Copenhagen University, Denmark. MacR1D is a one-dimensional seismic travel-time calculator for Macintosh. Travel-times vs distance are calculated for P and S arrivals (sorry, no converted phases or multiples) for sources at any depth. These may be compared to observed travel-times. This is a very quick way to define 1-d velocity models from observed arrival pics. Range is an interactive application for calculating the distance and azimuths between any two latitude/longitude positions. Range provides for a wide selection of spheroids. (Macintosh) UTM is an interactive application for converting coordinates back and forth between Universal Transverse Mercator (UTM) and geographic (Latitude/Longitude). UTM provides for a wide selection of spheroids. (Macintosh) Zoeppritz is an interactive application for calculating transmission and reflection coefficients. (Macintosh)