Over the past 40 years, more than 30 major blackouts worldwide were related to voltage instability and collapse. Among them, at least 13 voltage-related blackouts happened in the United States, including two major blackouts in the Western Interconnection in 1996 and a wide-scale blackout in the Eastern Interconnection in 2003. Several times, the blackout investigation teams indicated the need for on-line power flow and stability tools and indicators for voltage performance system-wide in a real-time. These recommendations are not yet completely met by the majority of U.S. power system control centers. The gap between the core power system voltage and reliability assessment needs and the actual availability and use of the voltage security analysis tools was a motivation to come forward with this project. The project's aim was to develop state-of-the-art methodologies, prototypes, and technical specifications for the Real-Time Voltage Security Assessment (RTVSA) tools. These specifications can be later used by selected vendors to develop industrial-grade applications for California ISO, other California Control Area Operators, and utilities in California.