“The Linux-powered scope produces a display that looks something like the heads-up display you’d see sitting in the cockpit of a fighter jet, showing the weapon’s compass orientation, cant, and incline. To shoot at something, you first ‘mark’ it using a button near the trigger. Marking a target illuminates it with the tracking scope’s built-in laser, and the target gains a pip in the scope’s display. When a target is marked, the tracking scope takes into account the range of the target, the ambient temperature and humidity, the age of the barrel, etc. It quickly reorients the display so the crosshairs in the center accurately show where the round will go.”
http://arstechnica.com/gadgets/2013/01/17000-linux-powered-rifle-brings-auto-aim-to-the-real-world/