That is much less important than you might think. Lua is not a general-purpose language. Its main usage is embedded inside a bigger "host" app, usually in C, f

That is much less important than you might think. Lua is not a general-purpose language. Its main usage is embedded inside a bigger "host" app, usually in C, for which it provides a higher level language. But the features available are completely defined and dependant on the host app. On top of that, Lua (or at least, its vanilla implementation) is very easy to tweak and understand. As a result, you can find Lua inside a car, a videogame or a web server ... and each incarnation of the language is incompatible with other versions of the language out there. Instead of a big continental platform, Lua is a fragmented archipelago of islands. You can still swim from one to the other, but you have to get wet.