The cw ruby laser reveals amazing properties, which have not been expected since its invention 60 years ago. CW pumping with a 405 nm laser diode requires an overall electrical power of only 6 W to achieve more than 100 mW in TEM00 at 694 nm for a linear resonator. In a ring cavity unidirectional single frequency operation with up to 75 mW, tuneable over more than 420 GHz is demonstrated. Experimental details will be presented, and possible applications will be discussed.