This is not embedding the C Lua runtime and compiler, but rather a
  complete implementation of Lua 5.3. This feat is made possible by the
  underlying Luerl library, which implements a Lua parser, compiler,
  and runtime, all in Erlang.

Okay, that's actually pretty cool (:

Also a sign of Lua's maturity and popularity, that it's got various independent implementations (LuaJIT, this one, perhaps others I don't know about).