Mavericks runs on the same machines 10.8 did, which is to say, no Power Macs, but it is nice that no new machines are left behind. It seems to continue some incremental improvements from 10.8 away from the overly iOSified interface of 10.7 and does not implement the excessive portions of the super flattened iOS 7 aesthetic, but it does not undo some of the irritating interface changes first introduced in 10.7 (scroll bars, ahem), and does not really add much to the underlying operating system other than some truly noteworthy improvements to energy saving. But hey, it's absolutely free. Whaddya want for free?
Instead of a full review -- if you want that, read John Siracusa's typically studious Ars Technica Mavericks analysis -- I think I'll just point out a few things especially relevant to us in the geriatric machine world that most of the 10.9 coverage has missed or not emphasized:
- No one has said what this means for Snow Leopard, and by extension, anyone still having a need to run PowerPC applications or anyone still rocking a 32-bit Intel Mac (or those of us whose token Intel Macs can't run 10.8 and refuse to update to 10.7). I'm presuming nothing good; I was surprised Apple still supported 10.6 with updates after 10.8 came out, and 10.6 is now four years old. Apple has historically not said when support ends for a particular version and it has always been inferred by what doesn't receive updates anymore. The last update as of this writing was in October 2013, consistent with Apple releasing a "final rollup" just before support is dropped in the wake of a new OS release.
- Apple has also declared war on plugins in Safari 7, just as Chrome and Mozilla have. Again, stealing from Siracusa's insanely detailed review, Apple has plugin blocking for both energy and security reasons in 10.9's release. It also shows considerable technical improvement in WebKit2, which because of its greatly improved reliability is now likely to completely eclipse the original WebKit in the very near future, and cannot be good news for Leopard WebKit.
- App Nap, the major power-saving framework in 10.9, is an integral part of Cocoa, and only Cocoa (and only GUI Cocoa apps, at that). Given Apple's increasing emphasis on battery life and power savings, it is eminently possible that this will accelerate the timeframe in which Carbon will be banned entirely from OS X. I would not be surprised if 10.9 is the last version of OS X with any Carbon support, but Apple to my knowledge has not taken the step of banning them from the Mac App Store ... yet.
Australis is still a big question mark. On OS X, there remain significant performance regressions, including some 10.6-specific issues. Now that 10.9 is out, this might accelerate Mozilla's desire to drop 10.6 support because we should expect some of the older Snow Leopard-only computers to get replaced (and drop Mozilla's 10.6 user base proportion), particularly if Apple is perceived to withdraw support. This does not mean that Australis can't be ported to 10.4, and because we are entirely software-drawn does not mean that we will have the same performance issues in exactly the same fashion, but it's a little concerning. It doesn't appear that it will be in Firefox 27 either, and there are still a lot of bugs on all the supported OSes.
The beta for TenFourFox 24 has been mercifully well-received, despite the benchmark regression. Most people find it more responsive overall than 17, which is very encouraging. Other than the known problem with Personas and window redrawing, the only other bug that has cropped up is a rare issue with an unresponsive menu bar. The app still works and can be quit and restarted, but the circumstances are not understood; I personally experienced it once, and I have not been able to trip it since. I do not consider this bug a showstopper at this time. I would appreciate anyone who has reliable steps to reproduce.
17.0.10 is building and should be available for testing by Saturday, our final 17 release. 24.0.1 will be released hopefully late next week as the last 24 beta. I am also planning to attack the 26 beta right away.