ITALASSI is a freeware program that has been written to facilitate interpretation of regression models (2 independent variables) with an interaction term. The program allows you to enter several regression models (two bivariate, one multiple additive, and one multivariate with interaction) in the form of equations or compute those equations from raw data and displays the various models using 2D and 3D graphs. The program may also be used in advanced stat courses to illustrate statistical interactions or applied multiple regression.