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It is well understood that the main function of tractors is to provide drawbar power either through the single-point connection known as the drawbar or through the three-point hitch. Early tractors essentially replaced horses and other draft animals to do work. Also, over the years, tractors have been called upon to provide other forms of power transfer, for powering and for controlling implement functions. This Lecture looks at other power usages and requirements, focusing primarily on mechanical means such as the PTO, tractor hydraulic systems, and more recently through transfer of electrical power. A historical prospective is provided for each form of power. One of the themes developed is how tractor and implement manufacturers can exploit available tractor power to improve efficiencies of the tractor implement system that will be beneficial to the end user of the equipment. The advantages and disadvantages of each type of power transfer as well as relevant standards and current practices are discussed, as are some future trends.