Why do we need 3 Vector3 types?

[SamJBarney]

It's called the Unified Programming Engine (UPE for short). It's kinda hard to fully describe without a large, large post, but it is being developed to allow people to write code in whatever language they want, and have it work seamlessly with any other language.
It could definitely replace tolua, and remove all of that binding code.

If you want, I could start a new thread that explains it all in detail, along with the pros and cons that I can see.