It's hyper-optimized, small, and can be multithreaded or multiplexed trivially, but that's true of lua as well. The array thing gives it a leg up in speed as well, as does 0-indexing. Finally, its gc algorithm doesn't have cpu bursts (it's not "stop the world"). I don't know of Lua has this feature, but it makes the language ideal for real-time applications. Like games.