The language syntax seemed uninteresting, which is not really a bad thing but what's the case for the need for a whole 'nother language in that category?
I don't think lua has integers ie. like Javascript everything is a double, that can be changed by redefining a macro and recompiling AFAIK but it's still one global numeric type (and you can't change it for luajit).
No; there are definitely some major differences between the two languages, but they seem to have a lot of similarities. Julia's obviously made for scientific work, and Lua's a general-purpose scripting language designed to be embedded in a host application, but they seem to have a lot of design constructs in common.
Lua also has 1-based arrays. Heh.