This book constitutes the refereed joint proceedings of five international workshops held in conjunction with the 24th International Conference on Conceptual Modeling, ER 2005, in Klagenfurt, Austria, in October 2005.

The 40 revised full papers presented together with the abstracts of seven tutorials were carefully reviewed and selected from 102 submissions. The papers are organized in topical sections on best practices of UML, experience reports and new applications, model evaluation and requirements modeling, metamodeling and model driven development, positions in engineering agent oriented systems, agent oriented methodologies and conceptual modeling, agent communication and coordination, geographic information systems, spatial and spatio-temporal data representation, spatial relations, spatial queries, analysis and data mining, data modeling and visualisation, conceptual modeling approaches for e-business, information system models quality, and quality driven processes.