Starting from the background of nanofluidics in other disciplines, this paper describes the present state of research in this field and discusses possible directions of development. Emphasis is put on the very diverse background of nanofluidics in biology, chemistry, physics and engineering and the valuable knowledge available in these disciplines. First, the forces that play a role on the nanoscale are discussed and then a summary is given of some different theoretical treatments. Subsequently, an overview is given of the different phenomena occurring on the nanoscale and their present applications. Finally, some possible future applications are discussed.