Previous chapters have provided a brief overview of cams, from their origins in antiquity to contemporary versions. This chapter summarizes their technical evolution and related studies. Again, only Western technology will be considered. For figures, please refer mainly to the previous chapters. Early cams were simple wooden slats mounted on a shaft and used to provide alternating motion to an oscillating rocker or translating rod. At this point, cam design was limited to a choice of number and length. However, even the earliest cams presented design problems. For several centuries, only minor improvements were made. An important development was due to the watchmakers of the eighteenth century. They were used to working with mechanisms, which led them to introduce complex cams in some watches and then to become makers of amazing automata. The first engineering studies on cams appeared between the seventeenth and eighteenth centuries. They focused on the transmission of forces in order to calculate resistances and the necessary power. Later, the problem of choosing the law of motion and drawing the cam profile was also considered. Cams were shaped according to certain functional requirements and the concept of optimizing the law of motion was introduced. The problem of improving the behavior of cam mechanisms operating at high speeds, or where inertial forces are otherwise relevant, then led to the introduction of elastodynamic modeling of the mechanisms themselves.