The Technology Program GAST was executed from 1981 to 1987 as a German-Spanish joint program aiming at the development and the investigation of necessary solar specific components and software for a gas-cooled tower power station of medium size. After the tests had been successfully completed at the Plata­ forma Solar de Almeria in 1987, the proceedings are now presented to inform the experts and the public about these developments and their results. Not intending to anticipate a detailed valuation of the results, however, we as the project monitors of the Technology program resume that the intended aims are nearly entirely achieved and that principally the way for the construction and operation of a gas cooled solar tower power plant has been prepared. Essential for this successful completion were not only a promising concept, a careful design, a precise plan­ ning, solid fabrication and installation as well as careful tests, but also the extraordinarily good cooperation between the engaged companies, institutes, organisations and advisory groups.