In this paper, we present an approach for the visualization of object-oriented software. This approach has been implemented in MetricAttitude, a visualization tool based on static analysis that provides a mental picture of a software implemented in Java by means of polymetric views. The approach graphically represents a suite of object-oriented design metrics (e.g., Weighted Methods per Class) and “traditional” code-size metrics (e.g., Lines Of Code). To assess the validity of our proposal, we have conducted two users' studies with students in Computer Science and professional software developers. The used empirical method is qualitative. To assess MetricAttitude and its underlying approach, we conducted questionnaire-based surveys. Results...