Only carbonized applications can take full advantage of OS X's newest features, but the system's "classic mode" provides backward compatibility. This mode allows Macintosh applications designed for earlier Macintosh operating systems to run smoothly under the new architecture. Macromedia Flash MX is fully carbonized and can therein utilize the perfomance of OS X, however Macromedia Flash 5 and the Macromedia Flash Player 5 have been extensively tested and are fully functional with OS X in classic mode.