The Full Arsenal achievement in FTL says you need 11 systems installed on a Kestral at one time.
So what counts as a system to do this? Augmentations? Weapons? Drones? Those seem to add to only nine possible. What else could you add?
Oh, I guess there is Cloaking Device and Teleporter... that could add to eleven if the weapons and drones count - do they? Is there something else?