In the 20th century, Danes have also been innovative in several fields of the technology sector. Danish companies have been influential in the shipping industry with the design of the largest and most energy efficient container ships in the world, the Maersk Triple E class, and Danish engineers have contributed to the design of MAN Diesel engines. In the software and electronic field, Denmark contributed to design and manufacturing of Nordic Mobile Telephones, and the now-defunct Danish company DanCall was among the first to develop GSM mobile phones.