Currently, all Lua package distributions I know simply create 'lua'
(and 'luac') binaries, possibly libraries, too.
What happens if you end up needing two separate versions? Choose
either. But this could easily be fixed by using 'lua51', 'luac51' etc.
command names instead of the common one. Then, there wouldn't be any
clash and users could pick & use Lua as they please.
The situation would be especially nice for people adding the
_application_ (and not Lua itself) to their system. They perhaps don't
even know what Lua is, let alone can decide upon version conflicts.