A surgical tool for minimally invasive surgery. In one embodiment, the surgical tool includes a proximal joint and a distal joint at opposite ends of a tube that constrain pivoting of adjacent parts to be about two perpendicular, intersecting axes. Three articulation control cable lengths engage and operatively couple the joints to control the two degrees of freedom of the distal joint. A manipulator and an end effector may be operatively coupled, with one cable controlling the opening and closing of jaws. In another embodiment, a surgical tool includes two flexible articulation elements mounted to opposite ends of a tube assembly. The tube assembly includes a proximal tube element and a distal tube element, with their ends rotatably mounted to each other. The mode of operation the tool may be changed between motion-following and motion-mirroring by rotating the distal tube element relative to the proximal tube element.
