RangeModel (2004-2012) was an animated, graphical, freeware application designed to demonstrate the mechanism behind the mid-domain effect (MDE), with tools for exploring the effects of both theoretical and empirical range size frequency distributions (RSFDs) for one-dimensional domains and statistical tools to evaluate the contribution of MDE to empirical patterns. Unfortunately, RangeModel not longer runs under current operating systems. The User's Guide is posted here for historical purposes.

Fortunately, thanks to Aniruddha Marathe,  a version for R is now available (RangeModelR), with key elements of the original RangeModel, and new tools as well.