With an immense increase in research, development, and application of objectoriented simulation (OOS) over the past decade, there is evidence that this technology is becoming the choice for modeling large, complex, and/or distributed systems. This paper discusses the features of OOS that dispose it to modeling these types of systems and compares the OOS approach with traditional simulation approaches. A review of OOS languages and environments is followed by a discussion of current issues pertaining to objectoriented simulation.