This volume is a collection of papers presented during the first International ACM-L Workshop, which was held in Tucson, Arizona, during the 25th International Conference on Conceptual Modeling, ER 2006. Included in this state-of-the-art survey are 11 revised full papers, carefully reviewed and selected from the workshop presentations. These are rounded off with four invited lectures and an introductory overview, and represent the current thinking in conceptual modeling research.