The Vision 21 Program is a relatively new research and development (R&D) program. It is funded through the U.S. Department of Energy's (DOE's) Office of Fossil Energy and its National Energy Technology Laboratory (NETL). The Vision 21 Program Plan anticipates that Vision 21 facilities will be able to convert fossil fuels (e.g., coal, natural gas, and petroleum coke) into electricity, process heat, fuels, and/or chemicals cost effectively, with very high efficiency and very low emissions, including of the greenhouse gas carbon dioxide (CO2). The goals of Vision 21 are extremely challenging and ambitious. As noted in the Vision 21 Technology Roadmap, if the program meets its goals, Vision 21 plants would essentially eliminate many of the environmental concerns traditionally associated with the conversion of fossil fuels into electricity and transportation fuels or chemicals (NETL, 2001). Given the importance of fossil fuels, and especially coal, to the economies of the United States and other countries and the need to utilize fossil fuels in an efficient and environmentally acceptable manner, the development of the technologies in the Vision 21 Program is a high priority. This report contains the results of the second National Research Council (NRC) review of the Vision 21 R&D Program.