Guest Editorial Frank Schweitzer, Dirk Helbing   In a world of fast growing population, intercontinental trade relations, and an ever increasing demand for technological innovations and economic growth in a developing society, the unterstanding of dynamic processes in economics is one of the major challenges of the twentyfirst century. In the life and social sciences, one is usually convinced that the evolution of social systems is determined by numerous factors, difficult to grasp, such as cultural, sociological, economic, political, ecological ingredients. However, in recent years, the development of the interdisciplinary field ``science of complexity'' has led to the insight, that complex dynamic processes may also result from simple interactions. Moreover, at a certain level of abstraction, one can also find many common features between complex structures in very different fields. The recent progress in the understanding of non-equilibrium phenomena in complex systems has also initiated a lot of activities in analyzing, modelling and simulating ``living'' systems with methods from statistical physics. Already in the early seventies, physicists have realized that these methods can help to understand social phenomena, such as opinion formation, migration, and settlement formation. But only very recently, physicists have focussed their interdisciplinary interests to particular economic processes, such as trading, market dynamics, or company growth. The joint efforts of many research groups spread over the world eventually lead to the establishment of econophysics - a young and fast growing field, the potential importance of which can be hardly overestimated. Even with the analysis of financial time series as its current focus, econophysics is meant to be a more comprehensive enterprise. Basically, econophysics focusses on the question how and to what extent methods from statistical physics can be used for the analysis, modeling, simulation, and optimization of economic systems. In order to make this enterprise a successful one, a broad and openminded dialog is needed between physics, economics and the social sciences. This dialog should help to overcome the gap between these different disciplines (i) by providing methods from the natural sciences, which could be adapted to solving problems in social or economic fields, and (ii) by increasing among natural scientists the sensitivity for problems in the fields of economics and the social sciences. The present special issue of Advances in Complex Systems shall contribute to this dialog by providing contributions of both physicists and economists in the challenging field of econophysics. These papers have been presented at an international workshop on Economic Dynamics from the Physics Point of View, which was organized as the 229th WE-Heraeus Seminar and took place in the Physics Center Bad Honnef between 27th and 30th of April, 2000 (see WEH-workshop.html for details). Basically, the workshop concentrated on two main problems: (i) the analysis of economic time series and other data with the aim of determining scaling laws and correlations, (ii) the investigation of microscopic models which mimic economic systems based on non-linear interactions of a large number of elements. Further topics were the statistical modeling of decision processes, the emergence of collective dynamics and chaos in socio-economic systems, as well as possibilities to control them. The particular emphasis of the workshop on dynamic micro-models intends to provide insight into economic interactions, which may eventually explain the complex dynamics found in the data. Similar to physics, where the structure, properties and dynamics of matter can be deduced from microscopic interaction laws, one would finally like to explain the observed macroscopic dynamics of organizations or companies, markets, and prizes based on non-linear interactions among a huge number of different individuals (agents). The various contributions of the workshop are published in the present issue of Advances in Complex Systems and a special issue of Physica A, 287/3-4 (2000). Both special issues have their own focus: Contributions with a close relation to statistical physics, especially those dealing with time series analysis of economic data, have been selected for Physica A, while papers focussing on multi-agent approaches to market behavior, technological evolution and applications of neural network techniques have been selected for Advances in Complex Systems. It is the hope of the guest editors, that the present special issue will stimulate fruitful discussions among physicists and experts in the socio-economic sciences and further the international activities and cooperation in the field of econophysics.