Software systems are complex and difficult to analyze. Reverse engineering is a complex analysis that usually involves combining different techniques and tools. Moreover, oftentimes the existing tools are not perfectly suitable for the task, and customization of existing tools, or development of new tools is required. Moose is an extensible reengineering environment designed to provide the necessary infrastructure for tool integration. Moose centers on a language independent meta-model, and offers services like grouping, querying, navigation, and advanced tool integration mechanism.