This chapter explores the process of gradually incorporating Swift 6 features into projects, including specifying which modules or files should utilize these new features. It also covers the implications of selecting Swift 6 as the language mode in Xcode settings, the new features in the Swift 6 compiler, and the benefits of opting in for strict concurrency. The conversation addresses concerns about transitioning to strict concurrency and the migration process to Swift 6, reassuring developers about incorporating new features without completely eliminating existing tools like locks and dispatch queues.