IRSTLM is no more supported on SourceForge.
Please visit the new IRSTLM official website:
http://hlt-mt.fbk.eu/technologies/irstlm
IRSTLM: A tool for the estimation, representation, and computation of statistical language models.
IRSTLM, the IRST Language Modeling Toolkit, features algorithms and data structures suitable to estimate, store, and access very large n-gram language models. Our software has been integrated into a popular open source Statistical Machine Translation...