Wikipedia
JMAG is simulation software for the development and design of electrical devices. JMAG was originally released in 1983 as a tool to support design for devices such as motors, actuators, circuit components, and antennas.
JMAG incorporates simulation technology to accurately analyze a wide range of physical phenomenon that includes complicated geometry, various material properties, and the heat and structure at the center of electromagnetic fields. JMAG has an interface capable of linking to third-party software and a portion of the JMAG analysis functions can also be executed from many of the major CAD and CAE systems.
JMAG is used actively to analyze designs at a system level that includes drive circuits by utilizing links to power electronic simulators. JMAG is also being used for the development of drive motors for electric vehicles.