Abstract: This paper provides an overview of the COM+ distributed component-based middleware that was introduced with the launch of Windows 2000. It is important to understand the capabilities of this technology since it will be present in the Australian Defence Force (ADF) Common Operating Environment (COE) and so will be available in many ADF systems. If this technology were taken advantage of, it would support the development of component-based distributed systems for the ADF without requiring large expenditures for new IT infrastructure. Looking further out the recently announced .NET platform will be a standard part of future Windows releases and so is likely to find its way into the COE as well. The .NET platform builds on COM+ services and concepts to provide a platform for building loosely coupled Internet-based applications.