Proceedings of the 3rd Workshop on South and Southeast Asian Natural Language Processing (SANLP), pages 191–200, COLING 2012, Mumbai, December 2012. Rule-based Machine Translation between Indonesian and Malaysian Raymond Hend y Susanto 1 Septina Dian Larasati 2 Francis M . Tyers 3 (1) Department of Computer Science, National University of Singapore (2) Institute of Formal and Applied Linguistics, MFF, Charles University in Prague (3) Dept. Lleng. i Sist. Inform., Universitat d’Alacant raymondhs@nus.edu.sg, larasati@ufal.mff.cuni.cz, ftyers@dlsi.ua.es ABSTRACT We describe the development of a bidirectional rule-based machine translation system between Indonesian and Malaysian (id-ms), two closely related Austronesian languages natively spoken by approximately 35 million people. The system is based on the re-use of free and publicly available resources, such as the Apertium machine translation platform and Wikipedia articles. We also present our approaches to overcome the data scarcity problems in both languages by exploiting the morphology similarities between the two. KEYWORDS: machine translation, Malay languages, morphology. 191