The aim of this paper is to illustrate and sensitize reader to the variety of perspectives and the fundamental nature of organizations as stable/stabilizing systems and as multi-perspective action systems. Researchers have been explicitly thinking about MAS/DAI organizations and attempting to link formal (human) organization theory with MAS/DAI models for at least twenty years. Despite this, the idea of organizations has been a peripheral theme in MAS/DAI research - primarily a specific coordination technique - not really one of the central intellectual issues of the field. The theory of 'natural' organizations has a somewhat longer, more diverse, and more thorough intellectual history than that of organizations in MAS. Beyond recent work in human social and organization theory, some newer research on abstract organizations has been attempting to unify concepts in biology, chemistry, physics, mathematics, and computing theory (e.g., the lambda calculus), with those of natural social organizations and multi-agent systems. The landscape for thinking about organizations in MAS is growing quite interesting, and this paper surveys this landscape. It presents and contrasts some conceptions of organization that have emerged and proven useful, and attempts to show how these have been imple-mented, experimented with, and applied. It also projects some future directions for research on MAS organizations, and gives some thoughts on where the most exciting issues lie.