JAVAVIS: Automatic program visualization with object and sequence diagrams using the Java debug interface (JDI). The goal of the JAVAVIS system is to help students understand what is happening in a Java program during execution. The primary focus of the first release is on sequential Java programs, although there is some support for visualizing concurrent threads. The system uses the Java Debug Interface (JDI), so there are no modifications needed in the Java source code for the extraction of information. The system shows the dynamic behavior of a running program by displaying several object diagrams and a single sequence diagram. There is one object diagram for each active method on the call stack. All modifications in the diagrams are done by smooth transitions.