From the manual: http://www.lua.org/work/doc/#changes
> new generational mode for garbage collection
(!)
> userdata can have multiple user values
> debug information about function arguments and returns
> new implementation for math.random
> new generational mode for garbage collection
(!)
> userdata can have multiple user values
> debug information about function arguments and returns
> new implementation for math.random
It's Xorshift128+, instead of random() or rand().