Abstract
Visualization for software understanding requires that the user be able to define specific visualizations that are specialized to the particular understanding task at hand. In this paper we describe a system that lets the user define such visualizations quickly and effectively. The system uses a visual query language over a variety of data sources to let the user specify what information is relevant to the understanding task and to correlate that information. Then it provides a mechanism for letting the user select and customize an appropriate visualization for this data.