Apple has officially renamed "Mac OS X" to "OS X". The transition has begun with OS X Lion (alias OS X 10.7). With the release of OS X Mountain Lion (alias OS X 10.8) the "Mac" within the product name is no more. I suggest to remove the "Mac" to reduce the size of the OS X User Agent. I think the UA could drop the "Mac" for all OS X version, because there exists the redundant "Macintosh" token. Although I understand that it could be useful to just drop it for 10.7 and newer versions. This will change the OS X UA from current: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:13.0a1) Gecko/13.0a1 Firefox/13.0a1 to: (with the removal described in bug 728582) Mozilla/5.0 (Macintosh; OS X 10.7; rv:13.0a1) Gecko/13.0a1 Firefox/13.0a1

I believe we're settled on the current UA approach