Receiver operator characteristic (ROC) curves are recommended to assess the diagnostic value of tests depending on a single cut-off value of a continuous variable. These ROC curves show the true-positive rate (sensitivity) against the false-positive rate (1-specificity). It is desirable, especially in situations with small samples of observations, to display confidence bounds of the ROC curve. This paper presents a Perl program which calculates the ROC curve and its distribution-free confidence bounds. A simple user interface also written in Perl permits their display.