The central part of GNUnited Nations is a makefile; actually a GNUmakefile since it heavily relies on features and extensions available in GNU Make. Thus, invoking a build consists of typing make on the command line, or within cron. If you are deploying the software on a non-GNU machine, probably GNU Make is installed and available as gmake or gnumake. If not, you should consider installing it, since the build will fail otherwise. See http://www.gnu.org/software/make for information how to download and install GNU Make.
If you don't specify a target, make by default builds the
target all, which in this case is to rebuild all translations
that are not up-to-date. However, there are special targets that do not
depend on the standard all target, which can be built by
make target. Some of the variables in the next section
apply to them, and some do not.