Plans as recipes or abstract structures, as well as plans as mental attitudes that guide an agent in its planning process has been enthusiastically embraced by both philosophers and AI practitioners. They play a central role in a class of rational agents, called Belief-Desire-Intention (BDI) agents. This dual view of plans can not only be used for efficient planning, but can also be used for recognizing the plans of other agents, coordinating one's actions and achieving joint intentions with...