In short, Lua's philosophy is to keep the core language as small as possible, but to include features that make it easy to add major language features as necessary. Adding an object system to the language is trivial, for example. (It doesn't have hygienic macros, though there are some side projects that attempt to add them. No experience with them, though...I'd just use Scheme.) Lua feels to me like a minimalistic, more internally consistent Python.