Zmorph extruder is the heart of Zmorph RepRap 3d printer (or any RepRap really;-)
Is't been designed to maximize travel in X and Z axis, and to be very easy to attach/detach. Together with dedicated carriage design, it creates a clip-on solution, secured with one screw only.
More details at thingiverse.com/thing:31158
Zmorph 3d printer : reprap.org/wiki/zmorph