[pka]

The graphics stuff is amazing, but I'd be also interested to know how they achieve hot-loading with C++. It seems to me that Erlang's philosophy (or FP in general) would be of great advantage here - just have the engine handle entity state and make all of the game world manipulating functions referentially transparent. This way one can swap code between world "ticks" (or update cycles) without worrying about breaking something.

I don't know how efficient something like that would be though; somebody mentioned cache issues with lumping heterogenous properties together, but maybe this could be optimized behind the scenes.