Instructions for building and installing Moses are online:

   http://www.statmt.org/moses/?n=Development.GetStarted

Some of the code is not originally part of Moses, but is periodically copied
into the source tree from elsewhere:

 * "bjam-files" is taken from Boost.
 * "util" and "lm" are taken from KenLM: https://github.com/kpu/kenlm