Research sponsored by the US Department of Defence's Defense Advanced Research Projects Agency (DARPA) under the Strategic Computing Initiative is reviewed. The program has emphasized technologies that would provide significant advances in four areas: scalability, real-time performance, reusability, and methodologies for integration. Some of the programs concern building and reasoning with complex models, including models for diagnostic reasoning, models for design, and generic models. Other programs focus on support technology: knowledge representation languages, architectures, and development frameworks. Contributions to strategic computing applications are briefly discussed.<>