The goal of this project is to develop the methods and applications of cylindrical algebraic decomposition (c.a.d.). The project includes the invention of improved algorithms for various subprocesses, the implementation of both such new algorithms and algorithms already devised but not yet implemented, and the replacement of the current c.a.d. implementation with a new implementation having improved structure and a more convenient, perspicuous and responsive interface. The project will also explore the employment of parallel computation, and the study and analysis of the behavior of the c.a.d. algorithm when applied to numerous examples of various kinds.