This special issue of the Journal of Universal Computer Science contains selected and extended papers presented at the First International Symposium on Agent and Multi-agent Systems: Technology and Applications (KES-AMSTA 2007), which was successfully held in Wroclaw, Poland, 31 May - June 1, 2007. This symposium is the first event in the symposium series on Agent and Multi-agent Systems, chaired by N.T. Nguyen, and supported by KES International and Wroclaw University of Technology. The aim of KES-AMSTA series is to provide an internationally respected forum for scientific research in the technologies and applications of agent and multi-agent systems. The issue also includes several invited papers from other authors.