We have implemented a customized Internet decision support system designed to engage men in the decision-making process for the management of localized prostate cancer. The system is delivered to patients in the patient education room of the UWMC Prostate Oncology Center. The system interactively guides the patient through a series of surveys, and delivers multi-media interaction modeling and decision support output, both of which are customized for the patient's preferences. The system is currently implemented on an open source platform.