I don't have much exeperience on lua, but I can't manage to launch lunarender on linux ('%' and before is my bash prompt):

% lua bin/lunarender.lua
lua: bin/lunarender.lua:5: module 'lunarender.reader' not found

% PATH=.:./bin:./lib:./lib/lua:$PATH lua bin/lunarender.lua
lua: bin/lunarender.lua:5: module 'lunarender.reader' not found

lunarender/lib/lua% lua ../../bin/lunarender.lua
lua: ./lunarender/reader.lua:5: module 'lxp' not found