Not quite bipedal, but pretty cool. In particular the article notes that
The event … was to show off the machine’s energy efficiency. Unlike other walking robots that use motors to control every movement, the Ranger emulates human walking, using gravity to help swing its legs forward.
Standing still, the robot looks a bit like a tall sawhorse; walking, it suggests a human on crutches, alternately swinging forward two outside legs and then two inside ones. There are no knees, but at the ends of the legs are feet that can be tipped up and down, so that the robot pushes off with its toes, then tilts its feet upward to land on the heels as it brings its legs forward.