Italassi is a free, regression-model interpretation tool designed for researchers, teachers in advanced statistics courses, or other interested individuals. It can be used to illustrate statistical interactions or applied multiple regression of regression models with two independent variables and an interaction term. A 2D line graph or a 3D surface graph can be used to display the estimated relationship between two independent variables and one dependent variable. Changes in the regression slope, relating a predictor to the dependent variable, can be observed at the desired value of the second predictor. It can either compute the estimated regression coefficients from the raw data or use estimates from regression equations computed from general statistical packages or from a published source. Italassi can also be used in advanced statistics courses to illustrate statistical interactions or applied multiple regression