ABSTRACT
User interfaces of software applications were some years ago usually limited in their design flexibility. The manufacturer of the systems determined the appearance of the interface. If their customers had particular requirements, the manufacturer would, if possible, implement these into the design. But otherwise, the design of the systems and of the user interface had usually just one single fixed format, determined by the manufacturer. In fact, the manufacturer was in his design of the user interface also limited by the technology then available (e.g. layout options, use of colour). Implementing the system’s user interface was also a job for specialists, that required extensive training in programming languages.
