What are the benefits though? I wouldn't say using Lua is a "primary factor", but Lua is:

* Simple yet powerful

* Supports multiple paradigms

* Fairly concise

* DSL friendly

* Very robust

* Small footprint

* About as quick as they come in this language space, even without LuaJIT

* Supported by tools, debuggers and a community

If I were contemplating building my own dynamic language to support something like a game engine there would have to be some pretty compelling arguments not to just use Lua. I'm sure you've thought about it - so what's the reasoning?