Barely a year after the release of Lion, this new OS nevertheless boasts an impressive list of new features. The overriding theme is unchanged from the release of OS X 10.7 before it: "Back to the Mac." In other words, a selective migration of the best bits of iOS to its big brother.
I am not going to attempt to exhaustively work my way through all two hundred plus features and write in detail about each and every one. The plan is to hit the highlights, tell you what's changed, and let you know why that's a good thing -- unless it isn't. In which case, I'll tell you why not. Think of this as the amuse-bouche to Ars Technica and John Siracusa's no-expense-spared tasting menu.
- Mountain Lion costs $20, but is free if you bought a Mac after June 11, 2012.
- It's available through the Mac App Store.
- You don't need to have installed Lion -- you can upgrade from Snow Leopard (but only the very last 10.6.8 sub-version) to Mountain Lion directly.
First up: the bottom line
There's some ways in which Mountain Lion is undeserving of big excitement -- or a full-on review. Since OS X 10.5 Leopard, Apple has changed its process for OS X upgrades; we're now getting vaguely-annual upgrades with healthy numbers of extra features for relatively modest $20-30 costs, rather than the near-biennial major upgrades of the past that cost more than $100.
As such, there's barely a decision matrix for the upgrade; if even a small number of the significant new features will be useful to you, Mountain Lion is a no-brainer. Similarly, the second some hot app you want ships that won't work on Lion, that's a no brainer too (for me, that'll be Tweetbot for Mac, which will be 10.8-only once it leaves public alpha).
So if your question is "is Mountain Lion worth the twenty bucks?" then the answer is "yup." You likely all guessed that, which is why I thought I'd put it up here and not leave you in suspense.
If your question is "what should I expect from Mountain Lion?" then keep reading. Hopefully I'll show you a few things to get excited about. It's a great update.
If your question is "should I install it right now?!" then read the next section very carefully.
Apple's routine updates to OS X might have lulled you into a false sense of security. Don't let that happen. This isn't iOS; Macs aren't backed up to an always-on iCloud safety net and Macs can be customised in a hundred thousand ways (yay!), which means there's a hundred thousand ways for an OS upgrade to go wrong (boo!).
I have two pieces of counsel, from someone who's had to recover a lot of data from broken computers over the decades. [If you don't want to take it from Rich, take it from Steve and Erica who have been prepping our readers for Mountain Lion since April. -Ed.]
First, consider waiting, for a few days if not longer. Some nasty problems have been known to slip past Apple's testers and into the wilds, and something you rely on -- some small utility or a printer driver or somesuch -- may not yet be updated to work with the new OS. 10.8 isn't that different from 10.7, so you're unlikely to have significant problems; nevertheless it might be worth looking through the Roaring Apps Wiki to check your apps will still work.
If you make any part of your living with your Mac, upgrade this advice from "consider" to "I strongly urge you to consider."
Second, backup, backup, backup. You should be doing this anyway, but I like to take a second backup before installing major operating system upgrades. On the Mac, my process is:
- Using Carbon Copy Cloner or a similar app, take a snapshop of my Mac's drive to a USB device.
- Reboot the Mac, holding down the Option key to make the "select boot device" menu appear.
- Select the USB device to boot the freshly backed up copy of OS X.
- Make sure it's all fully working.
- Reboot back to my normal OS X disk.
- Disconnect the USB drive, and maybe even your Time Machine drive too.
- Proceed with the upgrade.
If you follow this process, you can have peace of mind that the upgrade can't permanently damage any of your data.
Not every Mac can have Mountain Lion. As with all of Apple's upgrades, some older hardware has fallen by the wayside and will never advance past OS X 10.7 -- unless some enterprising hackers come up with workarounds, that is.
Specifically, the oldest supported model, by family, is:
- iMac: Mid 2007 (first aluminum-bodied model)
- MacBook (Polycarbonate): Early 2009 (the one with the Nvidia 9400M graphics card)
- MacBook (Aluminum unibody): Late 2008 (the only model there was)
- MacBook Pro: Mid 2007 (the first ones with Nvidia graphics)
- Xserve: Early 2009
- MacBook Air: Late 2008 (again, the first model with Nvidia graphics)
- Mac mini: Early 2009 (and again!)
- Mac Pro: Early 2008 (the second ever model, the first to offer quad core processors; for the first model, you can investigate this workaround)
There's some weird non-linear stuff at work here, with iMacs as old as 2007 working while Mac minis as recent as 2009 don't. Ars Technica suggests this is down to graphics cards that have 64-bit compatible drivers. This theory aligns with the most common distinguishing characteristic of the Mountain Lion-capable models; they are the first of their range to use Nvidia graphics, with the model immediately that came before them using ATI or Intel graphics.
Your Mac will also need a minimum of 2 GB of RAM, although we'd suggest that 4 GB is a more workable amount these days. Apple's spec sheet says Mountain Lion needs 8 GB of disk space, but again it's wise to have some extra headroom. You're also going to be downloading the 4.4 GB Mountain Lion installer from the Mac App Store so you'll need still more disk space to put it in, and hopefully a fast Internet connection too.
There's also a few features that are reliant on specific hardware. AirDrop, which is also in Lion, doesn't work on a few of the older Macs that appear on the above list; it requires a modern Wi-Fi chipset. There is a workaround for Lion machines with nominally incompatible networking, but it's not clear yet if it continues to work on Mountain Lion.
More annoyingly for most people, AirPlay Mirroring has much tighter requirements, because it requires a beefy graphics chipset for reliable realtime encoding, and to create the encrypted video stream that's sent to the Apple TV. It won't work on MacBook Pros before the Early 2011 model or other Macs from before Mid 2011. Our own Erica Sadun has some tips on working around these limitations.
i(can see clearly now the)Cloud is here
At the WWDC keynote in 2011, Steve Jobs said: "We're going to demote the PC and the Mac to just be a device. We're going to move your hub, the center of your digital life, into the cloud." That vision comes a good deal closer with Mountain Lion, which drives iCloud deep into the operating system.
It's almost everywhere you look, in fact. Firstly, there's settings and metadata syncing. A single sign-in with your Apple ID when you first boot Mountain Lion can immediately configure a wide range of settings and preferences in the following list of apps: (deep breath) Mail, Contacts, Calendar, Messages, FaceTime, Game Center, Safari, Reminders, iTunes, the Mac App Store, and Notes. Phew.
This works exactly how you'd think it would; any of those apps that have content in the cloud, whether from your iOS device or another Mac running Mountain Lion, have access to that content. So immediately after booting 10.8 for the first time, you can pull up Reminders and see your to-do list, or Contacts and see your friends. Your Mail signatures, rules, account settings, etc are synchronized. Any Safari instance can see all the pages open on every other Safari instance -- across iPad, iPhone, or Mac. And so on.
It's... well, it's all very much like iOS, in the best possible sense of the word. Fuss-free and frictionless and, when you stop to think about it, probably how we all wanted these bread-and-butter productivity apps to behave along.
One thing I'd like to put on my wishlist for future iOS/OS X versions: I don't particularly care for the actual apps for either Reminders or Notes. When Apple opened up the fully-featured Event Kit API for working with calendar entries on iOS, it encouraged the creation of an entire subcategory of alternate calendar apps (I'm partial to Calvetica, myself). All of these apps still use the built-into-iOS calendar, so they get iCloud sync for free. I'd like to see similar APIs for the reminders and notes facilities, so that we can see a similar ecosystem of alternate apps for these too.
iCloud isn't just about settings and preferences though...
You got your cloud in my documents
A number of Mountain Lion apps, such as Preview and TextEdit, will offer to store your documents over there somewhere (waves hands vaguely in the direction of North Carolina) and enable you to access them "from anywhere", where "anywhere" really means "a Mac or iOS device signed in to your Apple ID running the same app as you used to create the file in the first place." For example, as far as I can tell, documents synced to the cloud from TextEdit and Preview don't appear to be accessible by any apps on iOS 5 or 6, so that syncing is only meaningful between Macs running Mountain Lion.
(An aside: Apple's website clearly shows screenshots of Pages with the same iCloud support. As I write this iWork still doesn't support Documents in the Cloud, although it seems a safe bet that Apple will push an update to the iWork apps the day Mountain Lion goes live. You also can't see TextEdit or Preview files in the iCloud.com web interface -- only iWork ones are visible. Similarly, though, I can't rule out Apple updating that site when Mountain Lion is released.)
Documents in the Cloud has a very iOS-style interface. In supported apps the normal Open File dialog has an alternate view with a linen backdrop, chunky thumbnails, and a simple one-level-deep-only folder system for grouping files, just like app folders in iOS and Launchpad.
Syncing is done in the background, so you can work with your files even if your Mac is disconnected from the Internet; changes will be uploaded when you next connect. It's certainly simpler than the full hierarchal folder system us Mac users have been accustomed to until now, and it's a very different approach to that taken by cloud syncing solutions that look like a normal folder, like Dropbox and Apple's older iDisk.
Working with Mountain Lion installs on both my MacBook Pro and my iMac, I put Documents in the Cloud through its paces. First, I created a document on one Mac; within seconds, it was visible on the other. Leaving it open in TextEdit on the first Mac, I made some edits on the second. Within a couple of seconds, I saw the first Mac's TextEdit window automatically update with the latest text.
Then I got sneaky. I disabled Wifi on both Macs, and made conflicting edits in both files. When I reconnected them, a dialog window appeared pointing out that my modifications were out of sync, giving me the timestamps of each file, and asking me which one I wanted to keep.
Once I selected my preferred version, however, the other was deleted. If I wanted to keep both sets of edits -- suppose it was a blog post I'd been writing and I wanted to manually merge parts of both documents into one new one -- I'd be out of luck. If I was using Dropbox instead, then I'd be protected in two different ways; firstly, Dropbox's default behavior is to create "(conflicted copy)" duplicate files, so you can retrieve other copies of the file. Secondly, Dropbox maintains version history for all files through its web interface, so you can recover older versions of files. Documents in the Cloud offers neither of these niceties.
Another area where things get less clear-cut is if you want to open a file created in one app (e.g. TextEdit) in another (e.g. Pages). As it stands, you have to open the file in TextEdit first, then save it to the Mac's filesystem. Then open it in Pages again, and save it back to iCloud, but within Pages. Now you have two copies of the file in iCloud and a third on your Mac, all in mutually incompatible silos; you have to manually track which one is the current version.
Similarly, if you download a document from iCloud through the web interface (perhaps to edit it on someone else's Mac or a Windows machine), you have no means to upload it again -- you have to do something clunky such as emailing it to yourself so you can re-add it from one of your own devices. In seeking to make "the computer for the rest of us" simpler for basic Mac users, Apple has perhaps made things more complicated for the rest of us experienced OS X operators.
Documents in the Cloud also doesn't address my biggest gripe with this sort of lightweight app-oriented file system, which is that I can't group together related files of different types (say, a spreadsheet with some financial calculations and a word processor document with the report that summarises the figures). Is this because I'm a stuck-in-my-ways curmudgeon? Yeah, very possibly. Of course, the traditional filesystem is still there (and alternative cloud syncing solutions exist), so we're all free to each make up our minds.
One final note -- Documents in the Cloud support is restricted to Mac applications distributed through the Mac App Store. That's a defensible decision on Apple's part; iCloud gives every user a generous 5 GB of space for free, which is certainly not free for Apple to host, and commercial App Store apps generate some income for Apple to offset that. However, with Apple's sandboxing rules leading to some devs removing their apps from or never putting their apps into the App Store, that could turn out to be an irritating limitation for end users.
isn't really important." "iMessage: because message delivery order
As you are doubtless aware, the previously-available-in-beta Messages app is now baked into OS X. It has had some UI re-arrangements and tweaks, but it's not fundamentally different; if you used the beta you won't be surprised by anything you find here -- although it certainly seems to crash less. If you didn't use the beta, it's pretty much exactly what you expect anyway: functionally equivalent to iChat with the addition of New! And! Improved! iMessage support.
Messages has noble goals. It tries to unify your send-short-pieces-of-text-to-friends into one app, whether the friend is using is a traditional instant messaging system (it supports AIM, Yahoo!, Google Talk, just like the old iChat) or the newfangled iMessage (that semi-replaced SMS in iOS 5). Like most multi-protocol instant messenger clients, Messages does a decent job of to unifying these different protocols behind a neat interface. For example, the indication of which network a chat uses is handled via light grey text in the message field itself, just like how Messages on iOS says "Text Message" or "iMessage" before you start typing.
Video calling is also supported, with all chats having a "start video" button at the top right, with one tiny oddity. For AIM, Jabber, Google Talk and Bonjour, you chat within the Messages interface. But for iMessage contacts, the standalone FaceTime app launches instead.
So far, so good. Messages is somewhat let down by wrinkles in the iMessage backend though, and I don't think Apple has all those problems licked yet.
Consider my initial experiment on starting Messages for the first time. I was already chatting with two of my friends via my iPhone. I happen to know that these two friends have their "caller ID" setting in iOS to be their phone number -- not their Apple ID email address. So when I am chatting with them on the phone, the iMessage servers are routing messages based on that number.
Being a sneaky sort, I started a Messages conversation on my Mac using their email addresses instead. It went wrong in exactly the way I thought it would -- on both my iPhone and my Mac, I now had two separate message threads, both with the same participants. If you don't understand the technicalities of what's going on behind the scenes, this is confusing; if you do understand them, it's still annoying.
In my time with 10.8, I couldn't reproduce the other rare-but-too-frequent ways I've seen iMessage freak out on my over the last nine months -- the missing messages; the delayed messages; the messages I'm told haven't been delivered but have; the messages I'm told have been delivered but haven't; and on one particularly memorable instance the messages that arrived in a different order than how they were sent. However, these are symptoms of issues on the backend iMessage service rather than the client, so there's no reason to believe the release of Mountain Lion is going to change anything. I live in hope that Apple is working behind the scenes to improve matters.
Finger on the pulse: Notification Center
Notification Center is another of those "back to the Mac" features that was clearly derived from iOS, with a little bit of Growl mixed in for good measure. It's designed to be a unified system for every app that has to attract your attention to something, although the "unified" part is debatable because Notification Center, like iCloud, can only be used by apps distributed through the Mac App Store.
Notification Center is divided into two types of UI elements. The first are the pop-ups that appear when an app is trying to tell you something. Although conceptually similar to iOS, these are visually more like Growl -- small floating boxes that appear in the upper right corner of your screen. On an app-by-app basis, you can either turn these off, set them to "banners" (disappear on their own after a few seconds) or "alerts" (stay on the screen until you acknowledge them), as well as the option to play an alert sound or not.
Thus, you can create tiers of apps, giving the power to interrupt you only to those you value the most. When you really need to focus, you can drag the top bar of the Notification Center sidebar downwards to reveal a "turn all notifications off until tomorrow" setting. This is a thoughtful feature, although I wish it was a little more obvious; I overlooked it throughout most of my Mountain Lion testing.
The second part of the UI is the Notification Center itself, which is analogous to the pull-down display that iOS has. A click of the button in the menu bar icon in the top right corner of the screen, or a two-finger swipe leftwards from the right edge of your trackpad, will slide the whole of OS X to the left and let you peek at a long list of the various alerts and alarms and notifications that your Mac is asking you to see. As on iOS, there's a slightly-too-small close button to dismiss notifications on an app-by-app basis.
A quick aside about that two-finger-swipe gesture -- it feels very natural on a MacBook, where you can place your fingers on the casing of the laptop itself and swipe onto the trackpad. It initially feels a bit weird on a Magic Trackpad, however, as there's no casing to start from. To address this, Apple has made it fairly forgiving of what it considers to be "from the edge"; you can put two fingers anywhere on the rightmost half-inch or so of surface and swipe and it'll work. It feels awkward at first but stick with it and that'll soon pass.
One downside to Notification Center is the dreaded Beepocalypse. As I type this, I have my iPhone and iPad on my desk next to my iMac, where I am running Mountain Lion (with its built-in Twitter client -- more on that later) and Tweetbot for Mac. Every @-reply I receive on Twitter therefore results in four separate notifications. Or at least, it should -- only about 1-in-5 seems to be making it to Notification Center right now, although Mountain Lion isn't live yet so I'm not going to read anything into that.
It's really not clear what Apple could do about beepocalypses (beepocalypsii?). Perhaps future Apple hardware will incorporate something clever like NFC, or leverage Bluetooth in some manner, to sense when devices are close together and suppress extra notifications. That's not much of a solution, however. If my iPhone is in my hand and my iPad in my bag, I want notifications on the iPhone; if my phone is in my pocket and I'm looking at my iPad, the converse is true. Proximity doesn't really tell the devices enough to work out where my attention is, and hence where notifications should go.
Something involving iCloud syncing that removed "read" notifications on all devices when they were dealt with on one would help a lot, although there are still edge cases (such as Twitter notifications that come from mismatched clients). For now, I found that Notification Center encouraged me to re-evaluate exactly which apps were allowed to interrupt me, on which platforms, and in which ways (transient banners versus persistent alerts). I turned a few of the less important but chattier apps off and I've been a good deal happier since.
Notification Center also doesn't interact very well with Growl at the moment. At several points I saw overlaid Growl and Notification Center pop-ups appear on the screen, with one obscuring the other. Growl 2 will enhance support for this scenario, and doubtless we'll see more elegant support as 10.8 beds in and apps are updated, but for now it can get a little ugly, and you might want to move Growl's notifications from the default top-right corner.
One final curious footnote about the Notification Center UI: the drop shadow on the edge of the screen suggests that, on the Mac, Notification Center is "underneath" the main OS display -- whereas on iOS, it's rendered as if it's "over" it. This addresses Jake Marsh's insightful complaint that the use of linen as an "on top" texture in iOS in inconsistent.
The rain in Spain falls mainly on the plain
Yet another fresh-from-iOS feature is Dictation, the Mac's new "take a letter, Maria" feature that promises high quality voice-to-text transcription throughout the operating system.
The first thing to note is that Dictation requires a live connection to the Internet to work. Indeed, as soon as you turn it on (it defaults to off), it warns you that "what you say is sent to Apple to be converted to text." Behind the scenes, it'll be using the same voice recognition algorithms as Siri.
It works in all apps; anywhere you can enter text, you can press the shortcut key (by default you double-tap the Fn "function key") to activate it and talk away. Once you're done, it thinks for moment and then your text appears. Or, at least, some approximation of your text.
So how good is it? I used the built-in microphone on my iMac, so there was no special hardware -- no fancy headset or similar -- and read the start of this section aloud in my mild Welsh accent. This is what came out:
Yet another fresh from iOS feature is dictation the maxim you take a letter Maria feature that promises voice to text transcription.
The first thing to know is the dictation required Connected to the Internet to work. Indeed, as it is usually on it defaults to off, it was you that "what you say centre apple to be converted to text. Quote be home
At that point, it cut me off -- it seems it has a limited buffer size. As you can see, accuracy isn't brilliant for me out of the box, but I've only been playing with it a little so it's had no opportunity to train to my voice yet. Apple claims it will improve with use. I'm also a difficult subject; I have a relatively uncommon regional accent and (even when I'm trying not to) I'm told I tend to talk fast and blur words together.
Let's have another go!
Sorry about the port was the colour of television, teams to invest channel. "It's not like I'm using," case you someone say, as he shouldered his way through the crowd around the door of the chat. "It's like my policies are developed this massive drug deficiency."
That's supposed to be the opening sentences of Neuromancer by William Gibson:
The sky above the port was the color of television, tuned to a dead channel. "It's not like I'm using," Case heard someone say, as he shouldered his way through the crowd around the door of the Chat. "It's like my body's developed this massive drug deficiency."
It was at this point that I had the idea of taking the output of Dictation and looping it back through OS X's
say command to feed it back into Dictation again, then feeding that output into
say again, and so on to see what successive voice transcriptions would produce. I'm hoping to get purple monkey dishwasher out of it.
The skybox airport was the colour of television to intimidate shower
The skybox airport was the colour of televisions raising a shower
The skybox airport was the colour of televisions raising a shower
That was with the default Alex voice for the text-to-speech part, which is no longer the best OS X has to offer. Let's try another, using the higher quality "Daniel" UK English voice. This is the same synthetic voice as is used for Siri in the UK, that of voiceover artist Jon Briggs. (Bonus marks to any commenter who knows this quote.)
The house stood on a slight rise just on the edge of the village. It stood on its own and looked out over a broad spread of West Country farmland.
But I'll still likewise just unusual age is still has a look at overruled spread out west country farmer
Well still likewise just unusual ages still have a look at the morale spread out west country file
Well the likewise just unusually you still have a look at them all spread out west country file
I think Daniel speaks rather too quickly for Dictation...!
Despite that bit of fun, I could see Dictation being genuinely useful to anyone who doesn't feel a bit weird talking aloud to a computer (although I still haven't gotten over that), and extremely valuable to users who have difficulty typing due to physical impairment. I would particularly like to see Dictation expanded in the future to allow at least some modest amounts of control of the OS itself, rather than pure text entry; if Siri can send a text message, there's no fundamental reason my Mac can't create an entire email for me, not just the body text.
Dictation currently supports English (US, UK and Australian dialects), French, German, and Japanese. By a non-astonishing coincidence, these are the same languages Siri supports. Of course, if you're needing voice-to-text input in a scenario where you can't depend on your Internet access, Nuance's Dragon for Mac is available for $199.95 and will run on Mountain Lion (although apparently you have to temporarily turn Gatekeeper to 'low' to install it).
Sharing is caring
Hey, look! A new feature in OS X that's been directly copied from iOS! Shocker.
In a roundabout way, though, Share buttons predate iOS and even OS X -- they come from NeXTSTEP, the Unix operating system that Apple acquired in 1997. The Services menu lurking in every menu bar of every app you have on your Mac was an early attempt to civilise the prehistoric Unix pipe (|) and bring it into the GUI age. The idea was to allow any app to generate data in some format (a word, a chunk of text, a file, an image, ...) and allow the user to send that data to any other app that could do something meaningful with it (look it up in a dictionary, spellcheck it, email it as an attachment, upload it to Flickr, ...).
The Services menu has generally skewed towards power users rather than civilians -- it's often filled with barely-coherent geek talk that make it not particularly approachable. The near-ubiquitous Share buttons in iOS are an attempt to further refine the idea by making it more obvious what it does, and to make that functionality more visible. As of 10.8, now they are on your Mac, too.
Every compatible app in Mountain Lion -- including Finder, Safari, Contacts, Notes, Photo Booth and Preview -- has a prominent, always-visible Share button. We can probably assume that updates to the iLife and iWork app suites that add Share buttons will be pushed out via the Mac App Store when Mountain Lion goes live. Clicking this new button displays a small menu of options that are linked to the content you are manipulating. (Interestingly, the 10.8 version of the menu is rather more staid than the jazzed-up iOS 6 version.)
So, if you click the button in Safari, then by default you are working with a link to the page you are on right now; the options that appear are Add to Reading List, Add Bookmark, Email this Page, Message, and Twitter. In Finder, however, you are by default working with one or more files so there, the options are Email, Message and AirDrop. If you select an image file, that menu has two extra options: Twitter and Flickr. Photo Booth has a particularly rich set of options: all the same file transfer methods as Finder, plus it offers Add to iPhoto, Add to Aperture, Set Account Picture, Set Buddy Picture, and Change Twitter Profile Picture.
As you can see, much of the functionality of the Share button relies on having pre-set account details for various online social sharing services. Out of the box, Mountain Lion supports Twitter -- just like iOS -- and adds Vimeo and Flickr. These accounts are configured in the Mail, Contacts & Calendars pane in System Preferences, where they appear as new account types. Apple says Facebook will be added to this list "in the fall."
As with iOS though, support for Twitter (and, soon, Facebook) goes deeper than just the Share buttons. Once you've added your account, Notification Center will start alerting you to direct messages and @-replies you receive on the service, and will gain a "Click to Tweet" button at the top of its UI that, unsurprisingly, allows you to sent a tweet. Similar features are promised for Facebook, sending status updates and so forth, with an important extra feature: contact synchronization. But again, this won't arrive until the fall, so we can't be sure how well it'll work yet.
One small annoying thing about the Twitter notifications: clicking on them (e.g. on a direct message you want to reply to) opens the Twitter web site. I could find no way of making them open in any native client, not even Twitter's own one. In light of Twitter's recent rumblings about becoming less third-party-friendly, that worries me a little because it feels like a strategy, rather that an oversight.
Another notable downside to this otherwise appealing feature is the lack of third party support. If you use Flickr then you're fine, but if you prefer, say, 500px or Smugmug then you're out of luck. We can theorise that Apple will, in time, expand the sharing functionality to allow third parties to add their own data handlers in there; otherwise, we'll be forever stuck with just Apple's pre-approved choices, which will inevitably miss out some smaller sites that someone, somewhere wants.
AirPlay: video almost everywhere
My thesaurus is exhausted, spent, consumed. I'm going to say it plain: this is another new Mountain Lion feature lifted directly from iOS and grafted into OS X.
AirPlay Mirroring, as Apple is careful to refer to it, gives your Mac the same ability to route its display to a second- or third-generation Apple TV on your network that you already enjoy on your iPad or iPhone. It's absolutely trivial to set up: if you have compatible devices, an AirPlay icon should show up on your Mac menu bar automatically. Click it, select the device you want to mirror to, and you're all set.
AirPlay performed well in my testing, with source and receiver devices on a strong Wifi signal from my Airport Extreme Base Station. As soon as I switched mirroring on, my iMac's desktop was downsized to 1920×1080 (which is itself curious, as I have an older, 720p-model Apple TV), and a mirror of all the windows on my primary display appeared on the TV. The display was a little fuzzy, so in accordance with Apple's instructions I used the Displays pane of System Preferences to set my screen to "best for Apple TV"; this set my iMac to 1280×720. Using the Mac desktop felt fairly smooth, although there was an unsurprising hint of lag on cursor movement. Playing back a high definition MKV video file in VLC looked sharp, but there was some jerkiness to the motion; it also made my iMac run powerful hot after less than ten minutes of use.
Windows on my secondary monitor weren't mirrored, which is probably what you'd expect (and almost certainly what you'd want). Of course, when I quit AirPlay Mirroring, all my windows were now crammed into the top-left of my screen as they had all been resized for the lower resolution. That's a pain.
Apple is probably careful to call it "AirPlay Mirroring" rather than "AirPlay" because it's missing the logical second feature: sending an AirPlay stream to be displayed on a Mac. Perhaps of less interest to owners of portable Macs, but my 27" iMac makes a pretty good secondary television, so I would find that functionality occasionally useful. If you would too, there are a number of third-party tools that you may find useful.
How valuable you find AirPlay Mirroring depends a lot on the sorts of things you do with your Mac. My wife and I have found having an Apple TV quite useful for the ability to easily share photos or videos with each other without huddling around an iPhone; it'd be nice to be able to do that from our MacBooks too. Sadly, both our portable Macs are too old for AirPlay's stringent hardware requirements.
Mac-toting road warriors might get some mileage out of AirPlay Mirroring to deliver wireless presentations. However in my experience you can't rely on projectors in random conference rooms supporting HDMI or DVI input, and the Apple TV lacks VGA output (although adapters are available).
All work and no play means Jack has less skeumorphic UI to endure
Game Center is here. It still has that beyond-tasteless skeuomorphic UI, only now you can make it fill the screen of a 27" iMac if you really want to. It lets you compare achievements and high scores in supported games with a dedicated-to-Game-Center friends list, acts as a multiplayer hub for you to start games from, has in-game voice chat support in supported apps, and supports cross-platform gaming between iOS and OS X. It's not yet clear if achievements or rewards will sync between iOS and OS X versions of games, however; on the Talkcast this week, game publisher Gedeon Maheux said that he's not aware of a mechanism to handle that.
Game Center only works in supported games and as it's brand new there aren't many of those yet. In fact, as I write these words there is exactly one, Apple's venerable Chess; I expect more will appear soon. Dedicated "core" gamers will likely continue to feel it's a pale imitation of Xbox Live or Steam, but for the casual crowd it's perfectly fine. And that's all the news that's fit to print.
For a long time on the Mac malware scene, nothing happened. And then, without warning and despite speculation to the contrary, nothing continued to happen. There are still very few (although not zero!) credible malware threats that target OS X. This hasn't stopped Apple from doing something about it though, which is commendable. [In fairness, the logical time to install security cameras and deadbolts really is before the bandits and looters set up shop in the middle of town, not after. -Ed.] [I agree. I wasn't being sarcastic there, for a change! -RG]
The core change in Gatekeeper is an innocuous-looking setting in the Security & Privacy pane of System Preferences. You can set your Mac to run all software; only Mac App Store software; or software from the Mac App Store and "identified developers" by which Apple means developers enrolled in the Mac Developer Program who digitally sign their apps. The default is this last choice, whereas all OS X versions before Mountain Lion were equivalent to the first option.
This new setting confers extra protection. You can be reasonably confident that the Mac App Store has no active malware (or that any malicious app would be extremely short-lived there), so there's not much chance of infection on that front. Signed apps you download from anywhere on the web that are later found to be doing bad things can have their signing key revoked by Apple. This stops them from running on everyone's Macs.
On the face of it, it sounds like that middle option also means that none of your old software works, and that if you want to run just one unsigned app you're stuck having to turn it off. Fortunately, Apple thought of this. Gatekeeper stores a whitelist of apps that, even if they don't have the digital signature and even if you're using the "only run identified developers" default setting, will still run. By default, that whitelist contains every app that is on your system when you install Mountain Lion, so you won't immediately plagued by thousands of "this app is unsafe" messages the minute you upgrade.
If you download a new app, when you try to run it you get a "this app may be unsafe, so I'm not going to let you" message. However, you can get around this with a semi-obscure trick. If you right-click the app and select "Open" from the menu, you get a different dialog that allows you to open the app and add it to the whitelist.
Does this provide any meaningful extra security? Time will tell. If most users immediately switch to the most permissive setting, or if they become so accustomed to whitelisting apps that they don't stop to think before doing it, then arguably Gatekeeper will be of little value.
However, it's noteworthy than you can lock the Gatekeeper setting so it can only be changed from an Administrator account. This means it can provide a useful way to lock novice or untrusted users of your Macs to proven-safe software. System administrators of large Mac networks may appreciate that feature, as will parents and lab managers.
Gatekeeper isn't the only new trick that Security & Privacy knows. A new tab, Privacy, shows a comprehensive list of permissions granted by you to allow apps to access your data -- your current location, your contacts, your Twitter account, and so on. When you first load an app that needs access to this potentially confidential data, you get a notification dialog, and you can choose to forbid the app the access. It's another idea that's came over from iOS.
Some of the permissions are a little bizarre -- it wasn't clear to me why Apple's Pages word processor package was asking for me for access to my contacts -- but all in all it's a welcome change. I was initially concerned that Mountain Lion might start to feel a bit like Windows Vista's bothersome User Account Control nag-dialogs, but even during my first hours it wasn't particularly annoying and that quickly faded as I approved the apps I use regularly.
Everything old is new again
As usual, Apple has also taken the opportunity to make a raft of improvements to the core system apps.
Safari has probably seen the most changes. It's faster, for a start; rendering webpages felt snappier than before. The old school split top bar -- where URL and search box were separate fields -- is gone, replaced by something Apple is calling the "smart search field" which offers unified URL and search string entry. It's a concept you probably recognize from Chrome and modern-day Firefox, although it dates back at least as far as 2008's AwesomeBar plugin for Firefox. It works great, although I'm not a fan of the new graduated blue "load progress" bar that runs in the background of the text field. For some reason I can't put my finger on I found it visually distracting in a way that the old one wasn't.
Tab management has some new options. There's the much-publicised iCloud sync, for one thing; every device signed in to your Apple ID can browse a list of all the open tabs open in any copy of Safari, whether it's another Mac or an iOS (6 or later) device. This is very useful for the "I know I left that page open on my Mac, but now I want to read it on my iPad and I can't find it" scenario.
There's also new gesture support and a new UI for tab selection, called Tab View. I was initially confused by the little button on the far right of the tab bar; it pops up a sort of slide-though-tabs-as-pages interface, not dissimilar to the iPhone's interface. I didn't immediately appreciate why this was any better than simply clicking the tab directly, until I realised that it's intended to be used by gestures.
A two-finger pinch zoom-out gesture, when the page is already at the normal zoom level, switches to Tab View. Two finger swipes left and right moves through your open tabs, and a pinching zoom-in gesture brings the selected tab to the foreground. It's slick, fast and feels natural. It really comes into its own when you have a lot of tabs open and the tab title has become too small to contain useful text.
Mail gets Notification Center support (of course), Share buttons (ditto), and the new "VIP" system, which behaves the same was as it does on iOS 6. You mark a given contact as a VIP, and they then appear in your special VIP Inbox; additionally, any conversation thread in any folder will have a little star (rather than the usual dot) if one of your VIP contacts has contributed to it. It's vaguely similar to Gmail's Priority Inbox feature except that Gmail attempts to guess your important contacts automatically and Apple requires you to select them manually. Depending on how well Google's guesswork does for you, that could be a good or a bad thing.
Mail also has a few other smaller tweaks. One I particularly liked was that clicking on the grey "sort by" bar at the top of any mail folder jumps up to the top immediately, just like tapping the clock on iOS does.
Preview gets iCloud document syncing, as does TextEdit, as previously discussed. Preview can also handle dynamic PDF forms, plus it has the ability to search notes and highlights you add to PDFs. Calendar and Contacts have some new UI elements, including a useful "group" column in Contacts, and they've both been renamed to match their iOS cousins (so no more "iCal" and "Address Book"). Launchpad has a new search field, but I won't be jettisoning Alfred for it any time soon.
There's a grab-bag of miscellaneous changes too, including some stuff that's been removed. Web sharing is ostensibly gone from the base Mountain Lion install, having been banished to the OS X Server add-on (which costs an extra $20). This is slightly annoying, as I don't need the rest of the server stuff but I do sometimes use Web Sharing. The underlying apache executable is still installed on Mountain Lion -- I could go to http://127.0.0.1 in a web browser on a fresh install of 10.8 and see the default "It works!" page -- but some parts seem to be missing, like support for the Sites directories under each user directory. I doubt it's anything that can't be fixed with a little hackery.
RSS support is gone from Safari and Mail, Software Update has been removed, although confusingly the menu entry is still under the Apple icon -- it just opens the Mac App Store instead, which is where all future OS X updates will come from. The official X11.app is gone, too, although the project lives on as the open source XQuartz.
Full screen mode has been made very slightly less annoying on multi-screened Macs; you can now choose which of your displays will be used for full screen apps. When you click the "full screen" button, the app expands to fill whichever monitor it's currently on, whereas previously it would always move to the "primary display" (i.e. the one with the Dock and menubar.) People using laptops docked to big monitors will be happy about this.
There's no sign of any more meaningful support, though, like being able to put one fullscreen app on each display; you still end up with one screen full of linen. Unless, that is, you're using a rare app that supports multiple screens in full screen mode -- Aperture is the only one I can think of that does, but it proves that it is a solvable problem.
Unfortunately I was unable to test Power Nap because it only works on very specific Macs -- Retina display MacBook Pros and
Late 2010 (see below) or newer MacBook Airs (i.e. the ones that only ship with solid state drives). It promises to do three things while you Mac is in sleep mode: sync your emails and your iCloud data and documents, download updates to OS X (and possibly all Mac App Store apps; the documentation isn't clear), and perform Time Machine backups. As such, it's useful, though unlikely to change your life.
(UPDATE: At almost literally the last second, Apple updated the Mountain Lion Tech Specs page to remove support from the Late 2010 MacBook Air. It now requires a Mid 2011 or newer model.)
Time Machine has gained the ability to rotate backups between drives. Basically, you can now have more than one Time Machine disk attached; Mountain Lion will back up to all of them, seamlessly. This is useful if you want to keep one backup drive somewhere other than your house -- say, at a friend's or your workplace -- as your off-site backup. Online services like Crashplan make that seem a little old-fashioned, but the multiple-physical-disc approach still has value for people with a huge amount of data or very poor Internet connections.
Great OSs stick together
The overall impression I get from Mountain Lion is one of cohesion, on several fronts.
Apple is certainly bringing iOS and OS X closer together, at least superficially in terms of the user interface. Common elements like Notification Center and Share buttons are making these two very different operating systems start to feel like two sides of the same coin. That's a good thing, although I'll change my mind if Apple ever starts bringing the restrictions of iOS over as well. I believe this to be very unlikely, though.
iCloud syncing, both of documents and preferences, also brings greater cohesion to the process of using multiple devices, whether they are Macs or iOS or any combination of the above. As long as app support is there -- which is thin right now, admittedly, but it'll improve -- then access to your data is seamless. Having bookmarks, open tabs, email accounts, and all the rest sync between Macs is much appreciated.
Mountain Lion is certainly a worthy upgrade that, whilst it doesn't contain any life-changing upgrades over Lion, makes OS X a more productive operating system than ever before in a value-for-money package.