On the business front, Everett never slowed down. He diversified into the mini-computer business and, with one of his ex-employees, Elaine Tsiang Reisler, he founded the software engineering company Mono-Wave. (She was Elaine Tsiang when she had worked for Everett and, earlier, when she was DeWitt's student. Her married name was pure coincidence. Her husband was no relation to Everett's friend and colleague Don Reisler.) Mono-Wave is the only one of Everett's firms still in operation: its main business is speech recognition  He also delivered other software products to the market [54, 118]. And he branched out beyond scientific applications. Everett was founder and owner of Key Travel Agency in Rosslyn (a district of Arlington) and owned a condominium rental unit on St. Thomas. [54, 119]. Yet all of these were, as his wife wrote, "side ventures" .
Everett's business in DBS included such things as designing "a novel means of protecting computer files and programs, a method for detecting inefficiencies in the use and application of computers, an algorithm for scheduling the operation of a large-scale chemical plant, a method of optimizing the routing of school buses, techniques for data handling, and so many others" .