Editor’s Note: This article was originally published on February 17, 2012 when Apple first previewed Mountain Lion, the next major update to Mac OS X. It has been updated substantially following Mountain Lion’s official release.

Now that Mountain Lion is here, we can answer pretty much all your questions about the latest version of Mac OS X 10.8.

Availability

When will Mountain Lion be available?

It’s available now in the Mac App Store.

How much will it cost?

You’ll be able to pick up a copy of Mountain Lion for just $20. By way of comparison, Lion cost $30.

How will I get my hands on Mountain Lion?

The same way you got a hold of Lion—via the Mac App Store. Apple seems pretty happy with its online distribution method, with more than 26 million copies of Lion sold in the last year. When it’s time to pick up Mountain Lion, you’ll queue up in front of your computer rather than a physical store. Like Lion, Apple will let you pay for and download one copy of Mountain Lion that you can install to multiple Macs—a welcome feature for multi-Mac households.

Will I need to be running Lion to upgrade to Mountain Lion, or can I upgrade straight from Snow Leopard?

According to the information Apple has provided with the developer preview, you need to be running at least the latest version of Snow Leopard (OS X 10.6.8) to install Mountain Lion.

What version of Mac OS X is Mountain Lion?

10.8. (And it’s “OS X” now. With Lion, Apple’s marketing material began referring to “OS X” rather than “Mac OS X,” but with Mountain Lion all traces have been eradicated. Even the About this Mac box says “OS X.”)

Which Macs will be able to run Mountain Lion?

Apple says the following models are supported:

iMac: Mid-2007 and later

Mac mini: Early 2009 and later

Mac Pro: Early 2008 and later

MacBook: Late 2008 Alumnium, Early 2009, and later

MacBook Air: Late 2008 and later

MacBook Pro: Mid- and Late 2007 and later

Apple’s current specs page omits the 2009 Xserve, which was included in the supported models back in February. That may be more of a reflection of Apple’s regard for the now-retired Xserve than that machine’s ability to run Mountain Lion, however.

You may notice that some models supported by Lion aren’t in that list—just because your Mac can run Lion doesn’t mean it will be able to run Mountain Lion. Specifically, the following models can run Lion, but aren’t compatible with the initial developer preview of Mountain Lion:

2006 iMacs

Mid 2007 Mac mini

2006 and 2007 Mac Pro

2008 (original) MacBook Air

Early 2008 and earlier MacBook

2006 (15-inch and 17-inch) MacBook Pro

2006 and 2008 Xserve

Features

Mountain Lion has Dictation capabilities, but what about Siri?

Sorry, there’s no Siri for the Mac yet. Mountain Lion’s Dictation capabilities will let you talk anywhere you can type, with your words converted into text. That includes third-party apps and websites, according to Apple. Dictation will be able to support English (U.S., UK, and Australia), French, German, and Japanese.

If you want to ask your Mac what the weather’s like, though, it’s going to remain maddeningly silent. For that, you’ll need Siri and an iPhone 4S. (Or third-generation iPad, once iOS 6 extends Siri support to that device in the fall.)

So what about this Power Nap feature? What does it do?

Power Nap is a feature available to laptops with solid-state drives. It allows your Mac to sync and download updates while it’s sleeping. According to Apple, your Mac laptop will be able to Mail, Contacts, Calendar, Reminders, Notes, Photo Stream, Find My Mac, and Documents in the Cloud; keep the computer plugged in to a power source, and it will download software updates and make Time Machine backups, too. While that’s happening, your Mac runs silently—no lights or fans will come on, awaking you from any slumbers. (That’s why the feature only works with SSD-based Macs—no moving parts in your drive.)

I'm a frequent Facebooker; what can Mountain Lion do for me?

Apple promises Facebook integration for Mountain Lion, coming this fall. When that update hits, you’ll be able to share with the social networking service from within Mac applications. That means posting photos from iPhoto and links from Safari. Facebook notifications show up in Mountain Lion’s new Notification Center (more on that below), and you’ll be able to post status updates from there, too. Facebook integration figures to work like Twitter integration currently does on iOS device: You sign in, and you’re set up to share.

A potentially neat feature with Facebook integration invloves the Contacts app. OS X will add Facebook friends and their profiles to Contacts. When that information is updated on Facebook, OS X will update the Contacts entry, too.

Other Mountain Lion features announced this week include support for full screen apps on multiple monitors (though it doesn’t bring quite the full-screen support for multiple monitors that our own Dan Moren advocated for last year); iCloud Tabs for Safari, which show websites open on your other devices; and an offline version of your Safari Reading List.

Lion drew heavily on iOS for its feature set. Will that continue in Mountain Lion?

Yes. Like Lion, Mountain Lion offers numerous additions that will be familiar to iOS users. This OS X release continues Apple’s philosophy of bringing iOS features “back to the Mac,” and includes iMessage (in Messages), Reminders, Notes, Notification Center, Twitter integration, Game Center, and AirPlay Mirroring.

Are there any Lion features that Apple is dropping in Mountain Lion?

Largely, any features introduced with Lion are here to stay—though those of you who haven’t yet switched to Lion’s “natural” scrolling can rest easy: It’s still optional in Mountain Lion. iCal and Address Book receive name changes to Calendar and Contacts, and feature new layouts similar to their iOS counterparts. Certain apps, like Preview, have had their interfaces simplified. And RSS suport is being phased out of both Safari and Mail. (One ancillary consequence: the death of the RSS screensaver.)

What—if any—features in Mountain Lion will be available to Lion or Snow Leopard users?

Faster, cheaper OS updates from the company means less time to integrate newer apps with older operating systems; if you’re still holding back on upgrading, you’ll have to forgo the newest features. Apple did make a feature-limited version of Safari 6 available for Lion users.

So which iOS features will appear in Mountain Lion?

Mountain Lion will now share and sync Messages, Notes, and Reminders. It will also integrate Game Center, the gaming service Apple introduced to iPhone and iPad users with iOS 4.1. In addition, OS X will add its own versions of Notification Center, Share Sheets, syncing with iCloud documents and accounts, systemwide Twitter integration, and AirPlay Mirroring. Certain Mac apps have also taken design and functionality cues from iOS apps, like Preview’s new iBooks-style annotations and iChat’s transformation into Messages.

How will notifications work in Mountain Lion?

When you receive a notification, a small floating window appears in the upper right corner of the Mac’s display, containing the notification. Notifications come in two forms: banners and alerts. If it’s a banner, the message appears for a few seconds, then disappears from view; alerts require you to manually acknowledge them before they disappear. Clicking on a banner or alert will send you directly to the relevant application, while clicking and dragging dismisses the notification.

So who decides what’s an alert and what’s a banner?

You do. Using the new Notifications pane in the System Preferences app, you can set on a per-app basis whether you want your notifications to appear as five-second banners or alerts that remain visible until you click them.

That preferences pane is also where you can set which apps appear within Notification Center—think of it as the OS X version of the Notifications submenu in iOS’s Settings app. By default, Calendar, Reminders, Game Center, Safari, Mail, and Messages are configured to send notifications. You can also choose how many reminders appear per application—1, 5, 10, or 20 Items—and you can choose to display a badge on each application’s Dock icon when a notification from that app is received. You can additionally configure notifications so that a sound is played when a notification is received.

What if I don’t see a banner notification before it disappears?

If a banner notification disappears before you can get to it, you can bring up Notification Center by clicking on the Notification Center icon in the menu bar (the double circle in the upper right corner of the menu bar), entering a keyboard shortcut, or using a two-finger swipe. The desktop will shift to the left, displaying all current notifications in a dark gray column, sorted by app along the right edge of your screen. When you click on a notification in this list, the corresponding application will open and display the related item. For example, if you click on a Mail subject heading, Mail will open and display that message.

What’s the multitouch gesture to open Notification Center?

Starting at the far right edge of the trackpad, swipe with two fingers to the left (as if you were pulling something away from the right side of the screen). You can also assign a keyboard shortcut to show and hide Notification Center. You can do this within System Preferences -> Keyboard -> Keyboard Shortcuts.

Can you hide the Notification Center menu bar icon?

No.

What is Gatekeeper? How will it work?

Gatekeeper is a new security technology Apple has released with Mountain Lion, which allows you to download and install apps from developers registered with Apple, regardless of whether those apps are available for sale on the Mac App Store or on the Web. If an app that has been signed by a registered developer misbehaves, Apple can disable that app and ban the developer from creating new software registered with Apple. Read more about Gatekeeper in our hands-on with the new feature.

With Mountain Lion, will Gatekeeper prevent my current software collection from running? Will I only be able to run apps I download from the Mac App Store?

No; you’ll be able to open any software you choose to, though you can restrict this to Mac App Store-only purchases if you wish. In System Preferences -> Security & Privacy -> General, you can choose whether to run software exclusively from the Mac App Store; from the store and from non-Mac App Store developers who have registered with Apple; or from any developer, anywhere.

How will Mountain Lion’s sharing features work?

Like iOS, Mountain Lion has a new Share button that allows you to send just about anything—website, picture, video, file, text excerpt—using a variety of services. Those services vary depending on the app: For instance, in Safari, you can share websites to your Reading List as well as via email, iMessage, Twitter, and—in the fall—Facebook, while videos can be shared via YouTube, Vimeo, or AirDrop. If you right-click any text, you’ll be able to share that via email, iMessage, or Twitter, too. We take you up close with Sharing in Mountain Lion in this story.

In addition, the Mail, Contacts, and Calendars pane of System Preferences has been updated so that you can add systemwide integration with Twitter, Flickr, and Vimeo, along with three other China-based services.

How does Mountain Lion integrate with iCloud? What’s different from Lion’s iCloud integration?

Building off Lion’s basic iCloud integration, Mountain Lion will add support for accessing documents stored in iCloud; it can also set up your Game Center, Messages, iTunes, Mac App Store,and other Apple accounts automatically after you’ve logged in with your iCloud credentials. You’ll also be able to sync your notes, and sync your open Safari windows, too. Go up close with iCloud in Mountain Lion.

Will integration between iCloud and Mountain Lion replace any soon-to-be-dead MobileMe features?

You are referring, of course, to Apple’s having discontinued iWeb publishing, MobileMe Gallery, and iDisk in June. Unfortunately, there are no major MobileMe feature resurrections in Mountain Lion.

Does this foreshadow any changes in iLife or iWork? Does it break anything in iWeb?

Mountain Lion apps such as TextEdit and Preview have access to iCloud’s Documents in the Cloud, and Apple has now released a version of the iWork suite that works with that feature as well. It would be nice to see such an update of the iLife apps too, allowing users to transfer projects to and from their devices without wires or iTunes File Sharing.