Green Chemistry, as its name implies, is an environment friendly practice of using chemistry to prevent pollution. The US Environmental Protection Agency (EPA) created the Green Chemistry Expert System software that can be freely downloaded from this site. The program can be used to assess hazardous substances in chemical reactions, learn about green synthetic methods, design safer chemicals by modifying existing ones, consider alternatives to traditional solvents, or search for additional reference information. Each function is contained in one of five modules included in the program, and they give results based on user input for specific conditions and applications. Detailed instructions for installing and using the program can also be found on this Web site.