The science and technology of modified atmosphere packaging (MAP), continues to expand not only within the industry but also in terms of the technologies that are becoming available. MAP has transitioned from a standalone technology to a platform where unique science and technologies can be incorporated directly into the system to address a wide range of specific needs within the fresh produce industry. MAP is a platform technology that continues to expand its role in the extension and optimization of fresh produce quality by allowing management of factors such as ethylene, moisture and antimicrobial action. However, the amount of improperly designed commercial packaging highlights the need for knowledge about the fundamentals and importance of MAP. In this chapter these fundamentals of MAP design are reviewed and a substantive update on the advancements of the technology are provided.