Quoting from the creators’ web site:
The idea of this project was to create a fully-automated sentry gun, capable of picking out a human target and accurately tracking and shooting him or her in the heart.
This invention looks so cool and I loved it at the first sight, but,Oh my god! Where is the humanity going to?
They used Microsoft’s DirectShow technology and OpenCV library to read the pixels and translate them into targets and command the motors to move and shoot.
For more info, a look at their web site: http://cs-people.bu.edu/aaron/turret/turret.htm