A significant number of works dealing with multi- agent system reliability has enriched the area of mobile computing with approaches which can provide systems with fault-tolerant execution. However, the extent of this research topic is extensive enough to accept new approaches emerging in the light of changes within modern agent platforms, services which agents can offer and agent integration with new technologies. This book proposes a complete application-independent fault-tolerant layer for multi-agent systems which is able to support heterogeneous agent platforms from different vendors. The layer is developed as a typical three- tier application, where a large part of the application functionality is moved from agent platforms to a J2EE application server and is accessible via web-services or the persistent publish/subscribe messaging system. This book is intended for intermediate to advanced IT professionals who are interested in mobile agents and software reliability in general.