Ground penetrating radar (GPR) is a relatively new geophysical technique. The last decade has seen major advances and there is an overall sense of the technology reaching a level of maturity. The history of GPR is intertwined with the diverse applications of the technique. GPR has the most extensive set of applications of any geophysical technique. As a result, the spatial scales of applications and the diversity of instrument configurations are extensive. Both the value and the limitations of the method are better understood in the global user community. The goal of this paper is to provide a brief history of the method, a discussion of current trends and give a sense of future developments.