I've dropped the multi-package "erlang-*" builds in pursuit of simplicity. Instead the esl-erlang package is our direction.
fop is no longer installed, as we do not build PDF's. The documentation "chunks" are still generated.
fpm is used to generate the .deb and .rpm's instead of maintaining the debian/ and .spec files. The resulting artifacts are essentially the same for much less effort (including maintenance effort).
the default build concurrency is -j 2 within each erlang job, and all platforms are built in parallel.
additional build concurrency can be requested with make -j X but may be unnecessary.
symlinks are used where scripts are identical but could potentially diverge (i.e, at the OS level).
To summarise this effort;