The quiet, suburban neighborhoods and strip malls that line Route 128, the main highway that circumscribes the Greater Boston area, hardly betray the area's high-tech firepower. Since the 1950s, this corridor has played host to seminal technology companies such as Digital Equipment Corp., Raytheon and Sun Microsystems.

Amidst this high-tech stew, the corridor has also become a hotbed for military robotics, particularly those that roll or even walk on terra firma. Companies such as Boston Dynamics, iRobot and QinetiQ, all live within about 10 miles of each other and manufacture the Big Dog, Packbot and TALON robots respectively.

Scientific American visited iRobot and QinetiQ earlier this month for a first-hand glimpse of their military robots, and to see how they've been used and where the technology is headed next.   We also asked the military division heads of these companies for their views on the ethics of using armed robots in warfare. As political scientist Peter Singer writes in the July issue of Scientific American, the "growing use of robots…raises deep political, legal and ethical questions about the fundamental nature of warfare and whether these technologies could inadvertently make wars easier to start."