FusionReactor is a monitoring and troubleshooting tool that provides visibility into application performance and issues. It allows users to view current and historical requests, database activity, errors and more. The tool helps diagnose problems by showing stack traces, logs and other details. FusionReactor 6 includes new metrics, enhanced session tracking, and an option for cloud-based monitoring. An upcoming feature called Unattended Production Debugger will automatically fix problems without user intervention.