LIBLINEAR is a linear classifier for data with millions of instances and features. It supports: - L2-regularized classifiers - L2-loss linear SVM, L1-loss linear SVM, and logistic regression (LR) - L1-regularized classifiers (after version 1.4) - L2-loss linear SVM and logistic regression (LR) - L2-regularized support vector regression (after version 1.9) - L2-loss linear SVR and L1-loss linear SVR. Main features of LIBLINEAR include: - Same data format as LIBSVM, our general-purpose SVM solver, and also similar usage - Multi-class classification: 1) one-vs-the rest, 2) Crammer & Singer - Cross validation for model evaulation - Automatic parameter selection - Probability estimates (logistic regression only) - Weights for unbalanced data - MATLAB/Octave, Java, Python, Ruby interfaces