A "z-pinch" is a deceptively simple plasma configuration in which a longitudinal current produces a magnetic field that tends to confine the plasma. The simple geometry and low cost made it an early candidate for controlled fusion experiments. However, instabilities and rapid plasma loss motivated the development of more complicated plasma confinement systems such as tokamaks and stellarators. Recent experiments, in which z-pinches produced unprecedented levels of radiation and power, have led to renewed interest in the configuration. As a result, z-pinch research is currently one of the...