The Meka S1 Humanoid Head is a nine degree-of-freedom robotic active vision head. Designed for a wide range of expressive postures, it is the ideal platform for researchers interested in human-robot interaction and social robotics. The S1 system features high resolution FireWire cameras in each eye, integrated DSP controllers, zero-backlash Harmonic Drive gearheads in the neck, and the Meka M3 real-time control system.