McBain and McMahon are two prominent figures in the field of engineering design services (EDS). EDS is a type of engineering that focuses on the design, development, and implementation of products and services. McBain and McMahon are both well-known for their work in this field, and their combined efforts have helped to shape the industry. The three-letter acronym EDS stands for engineering design services, which is the field in which McBain and McMahon specialize.