An implementation of support vector machine (SVM) for the problem of pattern recognition, for the problem of regression, and for the problem of learning a ranking function. SVMlight provides methods for assessing the generalization performance efficiently. It includes two efficient estimation methods for both no error rate and precision/recall. The algorithm proceeds by solving a sequence of optimization problems lower-bounding the solution using a form of local search. SVMlight has been used on a large range of problems, including text classification, image recognition tasks, bioinformatics and medical applications.