StageGrow is a single-species population-modeling program. It has been written in Java for use on Mac OS X. StageGrow includes a stage-structured mode with up to five stages, a geometric growth model, an exponential growth model and a logistic growth model. Some of the models use environmental stochasticity in the calculations. I found out that this has to do with random variables. This program is obviously meant for use in education and research. It s not your everyday, let s have-fun-with-science project. Features include: Geometric growth graphs Help files with explanations of equations and variables, and example runs for some of the models A logistic model with an environmental stochasticity parameter The radio buttons that set which graph to display sometimes need to be selected twice in order to change the graph display. For more detailed information, including on updates, please read the documentation or visit the home page.