Information Technology often moves slowly and the potential of innovative concepts requires time to be fully understood. We know what happened with the history of the computer and its directions of development in general. Though the achievements of hardware technology were amazing, software development methodology lagged behind and did not consent full exploitation of the hardware. Even more strikingly, it took over three decades, until in the Seventies for the computer to be recognized as an interactive tool aimed not only at automatic computation, but also for assisting human beings in any of their activities. Especially with the appearance of the personal computer, and of graphic, intuitive interfaces including the concept of direct manipulation, the computer grew closer to naïve users. At the same time, it became evident that much further work was needed in human-computer interaction to make computers friendly and usable by a larger public.