Noncircular gears are not a mere mathematical curiosity with limited practical utility. They were first sketched by Leonardo da Vinci around 1500 and have since found their way into a variety of useful applications. In the 18th century, noncircular gears were used in flow pumps, clocks, music boxes, toys, and other devices. Early publications on the gear type in the 19th century by Hamnet Holditch (1842), Henry T. Brown (1871), and Franz Reuleaux (1875) helped evolve the field of kinematics. First introduced by Uno Ollson in his book Non-Circular Bevel Gear in 1959, the noncircular bevel gear has remained obscure due to the complex geometry. Even though more and more publications are available on noncircular gears, the knowledge is, especially compared to cylindrical gears, still very limited. But in the last decade, there has been an increased interest in the field of noncircular gears due to certain advantages they have over circular gears.