In this work, Morfessor, a morpheme segmentation model and algorithm developed by the organizers of the Morpho Challenege, is outlined and references are made to earlier work. Although Morfessor does not take part in the official Challenge competition, we report experimental results for the morpheme segmentation of English, Finnish and Turkish words. The obtained results are very good. Morfessor outperforms the other algorithms in the Finnish and Turkish tasks and comes second in the English task. In the Finnish speech recognition task, Morfessor achieves the lowest latter error rate.