2010a. Combining machine translation output with open source: The Carnegie Mellon multi-engine machine translation scheme. The Prague Bulletin of Mathematical Linguistics

The Carnegie Mellon multi-engine machine translation software merges output from sev-eral machine translation systems into a single improved translation. This improvement is sig-nificant: in the recent NIST MT09 evaluation, the combined Arabic-English output scored 5.22 BLEU points higher than the best individual system. Concurrent with this paper, we release the source code behind this result consisting of a recombining beam search decoder, the com-bination search space and features, and several accessories. Here we describe how the released software works and its use. 1