This article discusses the design and implementation of a new programming tool for Greek novices as a means to improve introductory programing instruction in Greece. We implemented Koios, a new highly interactive and visual programming tool for Greek novices, based on the body of research in the field of psychology of programming. The main contribution of this article is the empirical demonstration of the benefit of this tool in novice programming, compared with two other popular programming tools for Greek novices. The results show that users of Koios performed significantly better than users of the other two programming tools.