We propose to develop a practical, economically viable implementation of a highly mobile, full-sized humanoid robot. Called BYRUN, it will have the ability to walk, run, hop, and undertake other dynamic balancing activities. Robots with these capabilities are in high demand in research institutions and also have strong commercial application in the entertainment, marketing and science education sectors. Engineered Arts have lengthy experience in creating social robots with naturalistic human-like motion and interactive capabilities. We have been at the forefront of commercial production of full sized humanoid robots for the last half decade. BYRUN will build upon the expertise gained while developing the company's existing RoboThespian platform, but will have an innovative new design, resulting in a next generation robot capable of versatile dynamic movement, unlike anything else currently on the global market.