See subject.
That would be the Tag Track Xact targeting system -
http://tracking-point.com/innovations/tag-track-xact
Edit - beaten to the punch!
And is it everything a rifleman would want, and more?
I obviously have never handled guns, but, seriously, am interested in technology and how it used, as well as keeping track of marketing style. I actually spent some time in the 80’s, as a technology journalist, looking into head-up displays in aircraft.
It’s basically a tank main gun targeting system attached to a rifle, right?
Pretty much. I’m not sure if the tank main gun system has target tracking the way it works on the rifle, even. You select the target with the rifle and it uses some kind of image recognition to track the target as it moves and calculate where to shoot, taking the motion of the target into account.
From talking to a sergeant who drove tanks, he told me you have to manually track the enemy vehicle as it moves laterally, keeping the crosshairs on them, and you pull the trigger and the tank will calculate where to shoot based on the rate of lateral traversal and distance.
There’s a track point video of hunting in South Africa : they were having no trouble pegging animals at well over 1000 yards.
Back in WW1, battle rifles were sighted to 1000 yds or more. But then the modern assault rifle was developed after WW2 on the experience that comparatively few rifle kills were made at long distance. Is there a trend now to engaging targets at longer ranges again?
Couldn’t have gone with the obvious? 
Targeting systems are used in larger weapons. The best example in rifles (slash grenade launchers) I can think of is the prototype OICW program, especially the XM29.
But really, is this a “smart rifle” or “smart scope”? Also, it is unclear if this is even intended for military use. The image looks like it’s meant for hunting.
At a distance of 300 meters, a movement on the muzzle of .001 inches (a fine sheet of paper) will cause the line of sight to move 9 inches. Nah, moving target shooting past 500 yards is not practical. And less than that, any decent long-range scoped rifle will work.
This gun does it. Look at the video.
The way it handles it, it calculates the instant the barrel will be aligned correctly with the angles it needs to face to meet the targeting solution. It activates a servo to release the trigger lock a timed moment before the barrel will be correctly aligned. (so that by the instant of initiation of the round, the barrel is aligned)
The only thing the weapon cannot compensate for is unknown wind. The shooter has to tell the gunsight the wind speed and direction, but the shooter can only measure wind near where he is physically located.
Yes longer ranges are in again based on the Afghanistan experience. The bad guys are on the mountain one over and your M16/M4 is not quite cutting the range. The bad news is that closing on the enemy involves a damn tough hike down the mountain then back up the next one and he’s long gone by then. One fix was re-issuing the M14 rifles (7.62mm NATO) with scopes to individual squad members with shooting skills. Spec Ops got heavier barreled, more precision weapons. More sniper training, adopting the .300 Win-mag cartridge, heavier bullet weights, etc… contributed to better accuracy at distance.
The “fix” is theater specific. Most expected combat is still in the urban environment where light weight and compact size is more valued.
The various branches of the military did develop M14 sniper variants like the M21 and M25. Also in bolt action are .308 or larger calibers are the M24 and M40 (I am sure that there are more). They have the same base, but with lots of changes like better barrels and optics. I’m sure someone else knows the exact differences.