Aeon 6 is the name of the game system used in the Freejacks game. It uses six sided dice (D6's) as the primary dice.
The fundamental goal of Aeon 6 is to provide a smooth gaming experience that does not burden itself with reality. Yes, some elements of reality are important, and often necessary, but the realism doesn't overshadow what RPGs are supposed to be about: fun -- and let's not forget they are just games, not reality. Aeon 6 aims to ensure the game mechanics are simple enough that they won't get in the way of gaming, and that they have enough depth to allow a player to do anything they should reasonably expect to do in a game.