Together with OS X Mavericks, company Apple Lossless Audio CODEC (ALAC), has launched Safari 6.1 inside OS X Mountain Lion, this version of the browser bringing news available only in Mavericks. You can see in the image above that not all of them are available in the old version of OS X, so if you want to benefit from them, it would be better to install the latest version of OS X for free.
