During the last several years, the ?eld of agent and multi-agent s- tems has experienced tremendous growth, i.e., the topic has gained - precedented popularity. Meanwhile, the ?eld of formal methods has also blossomed and has proven its importance in substantial industrial and government applications. Thus, in 2000 it was quite timely to pursue a workshop to merge the concerns of the two ?elds. The need for such a workshop was particularly compelling given the growing concerns of agent-basedsystemsusersthattheirsystemsshouldbeaccompaniedby behavioral assurances. The Formal Approaches toAgent-Based Systems (FAABS¿00) workshop was the ?rst step in trying to address this need. The overwhelming response to FAABS¿00 motivated subsequent FAABS (¿02and¿04)workshops,aswellasthisbook,whichisdesignedtoprovide amorein-depthtreatmentofthetopic. This book is organized into four parts. Part I provides introductory backgroundmaterialonthetwocentraltopicsofthebook,namely,agents andformalmethods. Chapter1,byTruszkowski,isanoverviewofagents.Thechapter- gins by introducing the basic concept of an agent from a very simple, abstractperspective.Itthengraduallyre?nesthisnotionintoadetailed agent architecture, using the Goddard agent architecture as an ex- ple model. First, the major architectural components (e.g., percepts, - fectors,communications,reasoning,planning,execution)arede?nedand described. Then, agent behaviors are de?ned and related to the arc- tecturalcomponentsthatgeneratethem.Thechapterconcludeswithan intriguingdiscussionofmulti-agentcommunities.