The Guest Editors of the Proceedings of the 5th International Conference on Nitride Semiconductors (ICNS-5), Hiroshi Amano and Takashi Udagawa, have nominated the contributed presentation by Michael Kneissl et al. [1] as Editor's Choice of the present issue of physica status solidi (a). This paper is a report on ultraviolet InGaN, GaN and InAlGaN multiple-quantum-well (MQW) laser diodes with emission wavelengths between 368 and 378 nm, continuous-wave operation and a differential quantum efficiency of up to 4.2% which is remarkably high for these laser diodes grown directly on sapphire. The cover picture is a scheme of an InAlGaN MQW laser diode on sapphire substrate. Michael Kneissl is a Member of the Research Staff at the Palo Alto Research Center. He is responsible for device design, MOCVD growth, fabrication, and characterization of GaN-based short-wavelength laser diodes. The full Proceedings of the 5th International Conference on Nitride Semiconductors (ICNS-5) are published in physica status solidi (c) – conferences and critical reviews, Vol. 0, No. 7 (November 2003) (ISBN 3-527-40489-9). Conference papers can also be found in phys. stat. sol. (b) 240, No. 2 (2003).