Hi,
A few years ago I implemented a library to retrieve the list of fonts on Windows, OS X, and Linux: https://www.ctan.org/pkg/lualatex-platform I don't think it's widely used, but when I wrote it it worked reliably an all three OSes (http://tracker.luatex.org/view.php?id=555), and could be used as a starting point.
Thanks a lot for the pointer!
I have uploaded a compiled package for TeX Live 2015-W32: http://members2.jcom.home.ne.jp/wt1357ak/lltxplatform-w32-TL2015.tar.xz Try texlua test.lua for $TEXMFDIST/doc/lualatex/lltxplatform/test.lua. Best, Akira
