The Agent20XY series of workshop were jointly held from 1999-2007 at the University of Chicago, Argonne National Laboratory, and Northwestern University, and were intended to provide a meeting ground for a stimulating exchange of diverse views. Indeed, a topic reiterated throughout the workshops was the importance of continued conversation between experts concerned with the content, theories, and conclusions of individual subject domains and experts concerned with advancing the art and science of simulation. From such conversations there surely arose many unexpected and fruitful applications of the concepts and tools of complex adaptive systems. The proceedings are presented in that spirit.

Agent simulation was a new approach to the study of social, economic, and physical systems at the genesis of this workshop. Following the publication of Thomas Schelling's groundbreaking book, Micromotives and Macrobehavior (W.W. Norton, 1978), many scholars have made pivotal contributions that demonstrate the potential of complex, adaptive models for representing large-scale and emergent social processes. While many important effects have been demonstrated, this approach to studying complex systems is not yet a fully realized methodology. This workshop addressed several questions related to this new field of inquiry.