The topic .Stress and Strain. of this conference was ideally constrasted by the remoteness and quiet atmosphere of the meeting place Hotel Seehof In Ratzeburg, a small medieval town situated on a peninsula in lake "Kuchensee. east of Hamburg In northern Germany. With the participation of 53 leading experts from all over the world, the workshop covered the widest possible range from the advancement of bonding theory, new mechanistic insights into chemical transformations and physical properties of highly strained compounds to their use as building blocks In organic synthesis and even as probes Into the detection of enzyme mechanisms. Because of their specific reactivities small ring units can uniquely play their role in the construction of composite functionalities. Such functionalities can increase the elegance In natural and non-natural products syntheses, since they help to develop more convergent synthetic routes and Improve the necessary chemo-, regio-and stereo-selectivity. This book presents all of the 20 Invited lectures and is complemented with short versions of 12 contributed papers and 13 poster presentations. I am convinced that it will stimulate further rapid development of this field of organic chemistry, which recently has seen extensions into the bioorganic area as well as towards new materials. In fact, several .supra-natural" -at first sight exotic -compounds are already available In useful quantities and are being exploited to create vastly new molecular devices, i. e. compounds with unprecedented molecular functions and polymers with unconventional properties."