The Integrated Farm System Model functions on all of the major Windows operating systems. Input information is supplied to the program through three parameter files. The farm parameter file contains data describing the farm such as crop areas, soil type, equipment and structures used, numbers of animals at various ages, harvest, tillage, and manure handling strategies, and prices for various farm inputs and outputs. The machinery file includes parameters for each machine available for use on a simulated farm. These parameters include machine size, initial cost, operating parameters, and repair factors. Most farm and machinery parameters are modified quickly and conveniently through dialog boxes in the user interface of the program. Many of these files can be created to store parameters for different farms and machinery sets for later use in other simulations. The weather file contains daily weather data for many years at a specific location. The daily data include the date, incident solar radiation, maximum and minimum temperatures, and total precipitation.