While it was officially released in the famous Dept. of Defense Tri-Service Memo five years ago, the concept of a modular open systems approach (MOSA) has been around for some time and is not a new concept, said Jason Dirner, in his keynote address at the MOSA [Modular Open Systems Approach] Virtual Summit held February 22 and hosted by myself and Military Embedded Systems. What is new, however, Dirner said, is “common MOSA, [where] you have multiple programs and services conforming to the same standard,” which enables a greater level of reuse and portability across the community.