The chapters of this book have been presented at the 1st Workshop of the Nonlinear Control Network*, which was held in Ghent, March 15,16, 1999. These contributions give an overview of some of the current and emerging trends in nonlinear systems and control theory. As editors of this book we would very much like to thank the speakers at this workshop for their sti- lating presentations and for their efforts to bring this material to its current form, which we are sure will provide stimulating reading as well. Dirk Aeyels Franchise Lamnabhi-Lagarrigue Arjan J. van der Schaft 'The Nonlinear Control Network is a four year project within the framework of the European Commission's Training and Mobility of Researchers (TMR) Programme that started on December 1, 1997. There are nine partners involved: Dirk Aeyels Universiteit Gent Dirk. Asysls4rug. ac. be Belgium Alfonso Banos Universidad de Murcia abanostdif. um. es Spain Fritz Colonius Universitat Augsburg ColoniusCmath. uni-augsburg. de Germany Alberto Isidori Universita di Roma isidoriCgiannutri. caspur. it Italy Francoise Lamnabhi-Lagarrigue Centre National de la Recherche Scientifique lamnabhiClss. supslsc. fr France (coordinator) David H. Owens University of Sheffield D. H. OnensCshsffield. ac. uk England Arjan J. van der Schaft Universiteit Twente a. j. vanderschaftCmath. ut8ents. nl The Netherlands Fatima Silva Leite Universidade de Coimbra fleiteCmat. uc. pt Portugal John Tsinias National Technical University of Athens jtsinCmath. ntua. gr Greece url: Nonlinear Control Network http://nuH. supelec. fr/lss/NCN Contents 1.