The first few years of the 90s were extremely important for the development of software copyright both in the United States and Europe. In the United States major decisions redefined the idea/expression dichotomy in different cases. In Europe, countries are still in the process of harmonizing their national laws with the EC Software Directive. This study compares traditional and evolving copyright standards as applied to computer programs on both sides of the Atlantic. It has been said that recent case law has brought America closer to Europe. On the other hand, American experience is a guideline for distinguishing between the concepts of idea and expression in the sense of the software directive.