This discussion is really interesting for me, as I am the author of experimental Harfbuzz module (resp. LuaLaTeX package for binary library copied from SILE).
Isn't possible to use Luarocks to distribute binary modules? This unfortunately means that user would need to install luarocks and then modules by hand, but it's better than nothing. I have in mind two possible approaches: 1. use standard Luarocks and use modified module loader to load libraries. I used this approach in one answer on TeX.sx: http://tex.stackexchange.com/a/219228/2891 the problem is that we probably don't have access to paths used by Luarocks from LuaTeX, maybe we can extract them using io.popen("luarocks path","r") and parsing the output? 2. use modified version of Luarocks and install binary packages directly in $CLUAINPUTS The first option seems more realistic to me. Michal
