StealthNet, a GOTS product library, was derived from a research project with the U.S. Department of Defense. StealthNet is a library that features models for Live-Virtual-Constructive (LVC) framework for network simulation, test and evaluation of operational networks defenses against cyber attacks. It features models for adaptive and coordinated attacks, scalability to test attacks on large communication networks, cyber test and analysis using metrics to quantify the information and the operational impact of cyber offense and defense strategies. It enables an environment and methodology for testing blue systems against cyber attacks in order to discover and validate vulnerabilities and to assess mission impact. StealthNet has many components such as its cyber response capabilities, which include model jamming detection and prevention, encryption, firewall, anonymous routing, backup channels, eavesdropping, routing misconfigurations, Denial of Service, network and application scanning to name a few. It has the ability to interoperate in both live and virtual environments helping to determine and understand user behavior on how people communication with each other in a distributed test-bed with live cyber threats.