libocas implements an Optimized Cutting Plane Algorithm (OCAS) for training linear SVM classifiers from large-scale data. The computational effort of OCAS scales with O(m log m) where m is the sample size. In an extensive empirical evaluation, OCAS significantly outperforms current state-of-the-art SVM solvers. libocas also implements the COFFIN framework for efficient training of translation invariant image classifiers from virtual examples. WWW: http://cmp.felk.cvut.cz/~xfrancv/ocas/html/index.html