New directions of research in nonlinear system theory

In this paper we survey some recent developments in nonlinear system theory. The paper is divided into three parts, namely Foundations, Large-Scale Systems, and Geometric Methods. The first provides adequate background to follow the paper, while the other two sections give an overview of two of the more prominent areas of development in nonlinear system theory. Several examples are given at appropriate places, and the references include several useful sources of additional information.