EPIC (Executive Process-Interactive Control) is a human information-processing architecture that is especially suited for modeling multiple-task performance. The EPIC architecture includes peripheral sensory-motor processors surrounding a production-rule cognitive processor, and is being used to construct precise computational models for basic multiple-task situations. Some of these models are briefly illustrated here to demonstrate how EPIC applies to multiple-task performance, and helps to clarify some basic properties of human performance. Additional applications of EPIC to modeling human-computer interaction are briefly summarized. (Author)