This article introduces papers discussed in the August 1991 issue of the periodical "Communications of the ACM." The ability to communicate across disciplinary borders has become both a skill and a necessity for many computer professionals in the 1990s. The idea for August 1991 special section, "Real-Time Knowledge-Based Control Systems" originated in an AAAI workshop motivated by the recognition that constructing robotic systems capable of autonomous, flexible, intelligent behavior is an inherently interdisciplinary activity. As part of their technical discussions, the authors detail how this technology can be applied to such diverse areas as nuclear power plants, robotic vehicles, and chemical processing. In addition to the special section, August issue includes two computing practices articles. In "Impacts of Life Cycle Models on Software Configuration Management," authors survey the current state of the practice of software configuration management. The authors contend that some evolving software engineering practices will soon replace the waterfall model as the de facto standard in the field. In "A Storage and Access Manager for Ill-Structured Data," authors discuss the James system, which was designed to provide flexible storage and access for a wide variety of ill-structured data such as text, graphics, computer models, semantic networks, and production rules.