The Configurable radio with Advanced Software Technology (CAST) project is funded under the European Commission Fifth Framework IST programme. The Project started in April 2000 and it is to run for 33 months, with continuous contributions from its seven consortium members over this period. The CAST project investigates future software radio techniques, using JAVA-based intelligent processors for hardware configuration and new broadband RF front-end using sub-harmonic sampling methods for down-conversion. This paper describes the initial concepts and ideas, and summarises the results of the initial phase of the Project.