This was written just after Lua 5.2 was released. There have been improvements since then. Lua 5.3 introduced an integer type (64-bit), actual Boolean operators, a UTF-8 library, a way to yield across a C-boundary and a way to pack and unpack binary data. Lua 5.4 introduced deterministic finalizers (and a fall out from that is a limited form of constant local variables).
If you want Lua which is luajit compatible, do what I did and use Lua 5.1 for the scripting engine. This way, if luajit performance is ever needed, scripts written with my engine will not break.
Lua 5.1 + bit32 (because, yes, I like to be able to do bitwise and/or/xor stuff) is my current favorite scripting language.
I wonder if maybe it was a good thing in the end. Lua51/LuaJIT are now dead languages - no new design changes are going to happen. It is now a stable development target for which libraries can only accumulate.
