Few toolsets for reverse-engineering and understanding of C++ code provide parsing and fact extraction, querying, analysis and code metrics, navigation, and visualization of source-code-level facts in a way which is as easy-to-use as integrated development environments (IDEs) are for forward engineering. We present an interactive reverse-engineering environment (IRE) for C and C++ which allows to set up the fact extraction process, apply user-written queries and metrics, and visualize combined query results, metrics, code text, and code structure. Our IRE tightly couples a fast, tolerant C++ fact extractor, an open query system, and several scalable dense-pixel visualizations in a novel way, offering an easy way to analyze and examine large...