Lion: The Complete Macworld Review

In a decade, Mac OS X evolved from a curious hybrid of the classic Mac OS and the NextStep operating system to a mainstream computer operating system used by millions. It was a decade of continual refinement, capped by the bug-fixing, internals-tweaking release of Snow Leopard in 2009.

But the last four years have seen some dramatic changes at Apple. In that time, while Mac sales have continued to grow, Apple has also built an entirely new business around mobile devices that run iOS. Combine the influx of new Mac users with the popularity of the iPhone and iPad, and you get Lion.

Can Apple make OS X friendly for people buying their first Macs and familiar to those coming to the Mac from the iPhone, while keeping Mac veterans happy? That would be a neat trick—and Apple has tried very hard to pull it off.

(Before you read any further, you need to know that Lion isn’t right for one particular group of users: If you’re using an early Intel Mac powered by a Core Solo or Core Duo processor, you can’t run it. And if you rely on PowerPC-based apps that run on Intel Macs using the Rosetta code-translation technology, they won’t run in Lion. For more on the fate of older software, see Chris Breen’s series on Lion-incompatible software.)

A new kind of upgrade

Even before you boot into Lion for the first time, you’ll feel just how different it is from previous versions of Mac OS X. That’s because Apple has decided to release the upgrade primarily as a $30 download from the Mac App Store. After a 3.5GB download, there’s a new Install Lion app in your Dock and Applications folder. Double-click that, and the installation begins.

Back in the day, getting an OS X upgrade involved going to a store or ordering online and getting an optical disc. With the release of Lion, Mac users can get near-instant gratification. And the $30 price is remarkable—in the past Apple would’ve charged $129 for an upgrade of this scale.

However, relying on downloading alone for an OS release has its drawbacks. While the experience is clean and simple for the most common installation scenarios, things can get weird if yours isn’t one of them. What if you have a really slow Internet connection or low bandwidth cap? Downloading 4GB of data could be painful. What if you aren’t running Snow Leopard, which is required for the Mac App Store? What happens if your drive crashes and you have to reinstall Lion onto a new, blank hard drive?

Apple has answers to many of these questions, but the rules of the game have definitely changed. Company executives told me that users without access to a high-speed connection will be able to bring their Macs to an Apple Store for help in buying and installing Lion. And despite all the talk about Lion being available only via the Mac App Store, the company plans to release a $69 version of Lion on a USB stick in August.

Apple doesn’t provide an easy way to burn a DVD or format a USB drive as a back-up installer, though even Apple execs admitted that technically adept users will be able to figure out how to create a bootable installer from the contents of the Lion installation package. Wiping your hard drive entirely and re-installing Lion will be a different (and potentially more complicated) process than it is today with Snow Leopard, but for most users, installing (and restoring) system software under Lion will be a simpler process.

The good news is that, once you’ve got a Lion installer, you can copy it freely to all the Macs in your house (so long as they’re running the latest version of Snow Leopard) and upgrade them to Lion. Not only is that convenient, but it’s legal: The Lion download license covers all of the Macs in your household, making that $30 an even greater deal. If you’re planning on updating multiple Macs to Lion, though, be warned: the Lion installation app self-destructs after use. After you download it, move a copy somewhere else before installing, or you’ll have to re-download the installer from the App Store before using it on another Mac.

Scrolling and gesturing

Apple has been adding Multi-Touch gestures to OS X since the introduction of two-finger scrolling in the PowerBook in 2005. After the arrival of the iPhone in 2007, things really picked up steam. In 2008 MacBooks got a Multi-Touch glass trackpad, and in 2010 Apple brought the same gestures to the desktop with the Magic Trackpad. With Lion, Multi-Touch gestures are now front and center, and it’ll be interesting to see how users react.

For some users, gestures are already second nature; I can’t imagine using my MacBook without two-finger scrolling. As someone who uses the Desktop to store all of the files I’m currently working on, the four-finger flicking gesture that clears away all windows so I can see that Desktop is now burned into my muscle memory. (To do that in Lion, you now flick with three or four fingers and your thumb.)

But for others, gestures are completely foreign. When I mention two-finger scrolling to some people, they look at me like I’d just claimed that I’d been to the moon. (For the record: if you slide two fingers up and down on a trackpad, it’s just like you were spinning a mouse’s scroll wheel. Try it, it’s great!)

It’s true that gestures can be tricky to learn. Some feel natural, because the result mimics the gesture: the three- or four-finger flick that moves your windows out of the way and summons Mission Control; the three-finger sideways slide that moves you from one space to another; and the new four- or five-finger spread that reveals the Desktop. Others are less intuitive: the two-finger double-tap that provides an iPhone-like zoom, for example, or the double-tap with three fingers (not the triple-tap with two fingers) that produces a pop-up dictionary definition of any word onscreen. Nifty features both, but tough to remember.

Lion also dramatically changes the two-finger scroll. That’s because Apple has decided to change directions: In previous versions of OS X, if you slid two fingers upwards on a trackpad (or moved the scrollbar on the side of the window up), your view of a document moved up; the document on the screen seemed to move down, and you would see content higher up on the page. In Lion, if you push those two fingers up, it’s as if you’re physically pushing the document up; you see the content below what had been onscreen.

Apple says that after a few days of using OS X with this new behavior, your brain adapts and then you won’t be able go back to doing it the other way. It’s true: After three or four days, I was comfortable with the new scrolling orientation. If you’re willing to put up with a few days of weirdness, your mind will adapt. If you can’t, well, go to the Scroll & Zoom tab in the Trackpad preference pane and uncheck the Scroll With Finger Direction option; that will restore the old scrolling behavior.

Users of desktop Macs who don’t like trackpads will be grumpy about the change. Fortunately for them, you don’t need a trackpad to use Lion; most of the features you implement via gestures can also be activated using keyboard shortcuts or contextual menus.

With this change, Apple is syncing the behavior between the iOS and the Mac. Is it really necessary for the two platforms to be in sync? Right now, I’d say no. But it does make me wonder whether Apple is laying the groundwork for more crossover between the two operating systems. If someday there’s a touchscreen Mac or one that can run iOS apps natively, having a consistent scroll-direction philosophy will make sense. For now, though, if it hurts your brain too much, you can just turn it off.

Speaking of scrolling, scroll bars, and crossover between the Mac OS and iOS, Lion also introduces the biggest change to scroll bars since they were introduced with the original Mac in 1984. By default, scroll bars on Lion are invisible, just as they are in iOS. You see nothing on the right side of a document window until you begin to scroll with a trackpad or mouse. Only then does the scroll bar appear. When it does, it’s clickable and draggable; you can even move your cursor above or below the bar itself and click in a light-gray scroll lane to jump rapidly through a document. But when not in use, the scrollbar fades away.

As someone who has fully embraced the concept of scrolling via two fingers on a trackpad, I like this approach—I didn’t use that scroll bar space and generally don’t need to see it. But as with so many of the changes Apple is making in Lion, the company gives users who like the old way an out: In the General pane of the System Preferences app, there’s an option to always show scroll bars. If you like to click on those arrow buttons at the top and/or bottom of the old scrollbars, though, you’re out of luck: They’re gone completely. I can’t remember the last time I used them, so that doesn’t bother me.

Mission Control

Over Mac OS X’s lifetime, Apple has introduced several ways for users to cope with window clutter—the problem of having too many documents and apps open on the screen at the same time. Exposé, which lets you quickly see all of your currently open windows, was introduced in 2003 with Mac OS X 10.3 (Panther). Dashboard, that separate onscreen space for tiny widget apps, appeared in 2005 with Mac OS X 10.4 (Tiger). Spaces, which let you assign apps to multiple virtual desktops, arrived in 2007 as a part of Mac OS X 10.5 (Leopard).

With Lion, Apple has combined all of these features into a single interface called Mission Control. When you activate Mission Control by clicking on the Mission Control app in the Dock, pressing a keyboard shortcut (F9 by default), or gesturing (swiping three or four fingers upward), you see an Exposé-style view of all the currently running applications with thumbnail views of all their open windows. At the top of the screen, there’s a list of all available spaces—including not just the virtual desktops that the old Spaces feature offered, but also all apps running in full-screen mode and (by default) Dashboard.

Configuring those spaces is simpler now: If you want to stick an app or a window into a new space, you drag its icon or window towards the top of the Mission Control screen. As you drag, the image of a new desktop appears in the corner of the screen, with a helpful plus icon. Drop the icon or window on that image and a new desktop space is added to the array at the top of the screen. You can drag items from space to space, but can’t rearrange the order of spaces.

Though you can move between spaces via keyboard shortcuts and clicking, it’s best handled via a trackpad gesture. A three-fingered swipe left or right on the trackpad will take you from space to space. It feels natural; I’m more likely to use Dashboard now that it’s just another space. Fans of the previous Spaces will need to re-orient; the old way allowed you to create a two-dimensional grid of spaces, but Mission Control limits you to a single horizontal strip. However, working with those spaces can be disorienting: When you switch between spaces, the order of desktops can get mixed up; items that were floating on top can end up behind another window. There’s definitely some fine-tuning to be done here.

I like the visual, tactile approach Apple has taken with Mission Control. I’m not sure if novice users will ever take to organizing windows and apps on multiple desktops. But since every full-screen app gets its own space by default, many people will end up using Mission Control whether they want to (or know they are) or not. I also wish there was a way to manually re-order spaces. Still, while Spaces had its adherents, I think Mission Control will be embraced by many more Mac users. By bringing Exposé, Spaces, and Dashboard together into a more unified whole, Mission Control is greater than the sum of its parts.

Full-screen apps

Lion adds a new capability that any app can take advantage of: the ability to run in full-screen mode. Once an app is updated by its developer to support this mode, a double-headed arrow icon appears in the top-right corner of the app window. Click on it and a couple of things happen.

First, of course, the app slides into full-screen mode: You see nothing but that app; no other windows share the screen. Also, the menu bar and Dock disappear. (Really, they’re just hidden; if you nudge your mouse to the edge of the screen they will reappear temporarily). And the app becomes a space unto itself in Mission Control. To exit full-screen mode, you move your cursor to the top of the screen and, when the menu bar reappears, you click on the blue double-headed arrow in the top-right corner.

This is an interface approach that Apple has been heading toward for a while: The existing versions of iPhoto, iMovie, and GarageBand all want to be run in single windows, as large as possible. With Lion, more Apple apps join that party, including Safari, Mail, and iCal. Presumably, many third-party apps will follow.

It’s interesting that Apple has decided to take this approach. On the one hand, it’s another way that Mac OS X now mimics iOS. But on the other, it’s also a throwback: One of the first things I noticed way back when I first compared the Mac with PCs running Windows was that Windows took a monolithic approach to apps: They were largely meant to run maximized, with one giant window taking up the full screen. That was very different from the Mac, which had an interface full of small, interrelated windows. Now, here we are in 2011, and Apple has seemingly embraced that monolithic approach, at least in some cases.

Lion’s full-screen mode can’t be judged on its own. Instead, we need to judge the way each app uses it. Some apps, such as iCal, iTunes and GarageBand, are essentially one giant window, so they're tailor-made for full-screen. Mail’s wide, multi-paned approach fits well, too. On a small display like an 11-inch MacBook Air, full-screen mode is especially helpful in eking out a little extra space.

Full-screen mode is less successful in other Apple apps. Safari especially feels like a failure: Most web pages just don’t need to be as wide as your screen; they’re designed at fixed widths, and nobody wants to read super-wide lines of text anyway. Sure, Safari has the new Reading List pane to fill up space on the side, and it could find other things to put over there (bookmarks, history). But I still don’t see the appeal of forcing my web browser to take up 100 percent of the screen, even on a MacBook Air.

If app developers come up with good uses of all that extra space, full-screen mode could be great. For example, one of my favorite apps, the long-form writing tool Scrivener, has a multi-paned interface that could be perfect in full-screen mode. There’s a writing section in the center, with controls at the top, a binder full of different sections on the left, and (optionally) an inspector pane with more detail on the right. It could usefully take advantage of the full screen.

But if vendors just make their existing apps as wide and as tall as possible, full-screen mode won’t be that useful. One third-party Twitter client app I tested had enabled full-screen mode on an experimental basis, but all that happened was that individual tweets appeared at full-screen width. That sort of approach will probably be common, but it’s a waste of time. In most cases, app developers will need to give some serious thought to how best to use full-screen mode, or the feature could become a largely unused gimmick, kind of like Dashboard.

Note that full-screen mode has apparently been designed for Macs with just one display. On a two-monitor setup, one display shows the app, the other shows nothing but the newly ubiquitous linen background texture. It's a waste. I’d much rather have two apps running in full-screen mode, one on each display, or even have one app in full-screen mode while the other screen is displaying one of my regular desktops. Until Apple addresses this issue, I can’t really recommend full-screen mode for anyone who relies on multiple displays.

Launchpad

Launchpad is one of the most obviously iOS-inspired new features in Lion. It’s the Mac version of the app home screens you see on an iPhone and iPad. Like Mission Control, Time Machine, and Dashboard, Launchpad is a basic operating-system feature that looks like an app itself: It’s in the Applications menu and, by default, in the Dock. You invoke it by launching the app, by using a hot key, moving the cursor to a hot corner, or by performing a Multi-Touch gesture.

The contents of Launchpad are essentially the contents of your Applications folder. Every launchable app in that folder shows up in a tiled list of icons in Launchpad. Apple stocks its own apps on the first page of Launchpad; other apps are listed alphabetically starting on page two. New apps you add, including those downloaded from the Mac App store, appear at the end of the list.

You can re-organize the apps in Launchpad much as you do on iOS: by dragging app icons around one by one. Drop one icon atop another and you create a folder (which you can rename). You can even delete apps you bought on the Mac App Store by clicking on an “X” icon next to the application icon.

Launchpad seems like an excellent solution for new and novice users, allowing them to survey all the apps on their system and find the one they want to open. For users familiar with iOS conventions, it will feel familiar. It appears to be an effort to steer those users away from the Finder and into an easier-to-use, more familiar launching interface; the Dock’s just not big enough to encompass every app you might have.

For Mac users with some experience, or just those with lots and lots of apps, Launchpad will be a disappointment. Organizing it is just as laborious as organizing home screens on iOS: It’s an endless series of clicks and drags. You can’t remove or hide items from Launchpad; every little AppleScript and installer utility on my system showed up there. Instead, you can exile them to folders on Launchpad’s back pages. It turns out to be a lot of work for something that’s supposed to be simple.

And that’s probably the truth of it: For people with a few downloaded Mac App Store apps and the stock stuff that comes when you buy a new Mac, Launchpad is a decent organizing tool. The rest of us might just want to pull it out of the Dock, turn off all the keyboard shortcuts and pretend it doesn’t exist.

The Finder

Despite all of the new interface elements, the Finder is still the hub of activity on the Mac. For many people, the Finder is the Mac: it’s the thing that’s always there, even when you’re not running any apps. But while Apple isn’t necessarily trying to kill Finder, it is trying to get us to spend less time futzing around with files and folders.

One way it does so is with the new All My Files view in the Finder. It’s basically a Spotlight search for every file an end-user might interact with, including contacts, events, to-do items, images, PDFs, and so on. I’m actually surprised it took Apple this long to come up with it.

Another way the Finder makes files and folders less futzy is the Arrange By command, which now divides the window into sections, with files and folders sorted and separated accordingly. It’s on by default when you view All My Files, but it’s also available in any Finder window. You invoke it from the item arrangement drop-down menu in the Finder toolbar or by selecting View -> Arrange By. In either case, you can select to view files by kind, name, application, the date they were last opened, modified, added, or created, and more. As with so many other Lion features, if you don’t like this one you can tell the Finder to display files in the classic style by choosing View -> Arrange By -> None. But I found it a great convenience to organize All My Files by Date Modified; it gave me an at-a-glance look at all the files I’d used in the past few days. Most of the time, whatever I was looking for was in that list.

All My Files doesn’t show you every file and folder on your system. That’s part of an apparently concerted effort by Apple to simplify the Mac experience for less advanced users. Other ways it’s doing so: The user Library folder is now hidden by default. You can still get to it (by choosing Go -> Go to Folder… or typing Command-Shift-G, then entering in ~/Library, for example, or by opting to make hidden files visible). And when you try to drag an app out of the Applications folder, the Finder will create an alias for it rather than actually move the app. (You can hold down the Command key while you drag to really make it move.) Neither of these changes is earth-shattering, but they indicate Apple’s new way of thinking: The company is trying to anticipate points of confusion among new Mac users—poking around in sensitive folders, moving apps inadvertently—and close them off.

Yet another change to the Finder is one that will probably benefit advanced users even more than novices: The search box in the Finder has been dramatically improved. When you type in a search string, you can specify exactly what you’re searching for from a drop-down menu: if you type logo, for example, you can choose to look specifically for files with logo in their names. You can also combine multiple search terms: do your logo search, then type image and select Kinds: Image from the drop-down, and you’re searching only for images with the word logo in the filename. You could do all this before with Spotlight wildcards, but it’s vastly easier to discover and use now. I wish the systemwide Spotlight menu behaved the same way, but it doesn't.

As with just about everything in Lion, there are other, smaller changes scattered throughout the Finder that longtime Mac users will likely notice. The sidebar has been redesigned to look more like the one in iTunes, with monochrome icons. Quick Look views have been redesigned and now feature a button to open a document in its default app. You can now select a bunch of files and use a New Folder With Selection command to file them all in one place.

Auto Save and Versions

Anyone who’s ever lost work because of a computer or app crash probably presses Command-S reflexively all day long, just to make sure everything is always saved. With Lion, Apple’s trying to make it so you never have to save a file again in order to protect your work. It’s also giving you the ability to reach back in time and retrieve previous versions of your documents.

Your favorite apps will need to be updated to take advantage of these two new features, Auto Save and Versions. But once they have been, they’ll all behave the same. Except in newly created files, the Save command will vanish from the File menu. Command-S will now invoke the Save a Version command. Save As has turned into Duplicate. And there’s a new Revert to Saved command that gives you access to all previous versions of your document—it’s like Time Machine for every file in every app that supports Versions.

To be honest, if someone didn’t tell you there was a new Auto Save feature in Lion, you probably wouldn’t notice. And that’s the point: Auto Save is intended to be completely invisible. Every chance it gets, the system will automatically save your file as you’re working on it. What’s on your screen is what’s on your disk. It’s no longer incumbent on you to remember to save your files. If you want to hit Command-S, your app will specifically stop and save the file at that point, but that step is entirely optional. And if you make a bunch of changes to a document and then try close the window or quit the app… nothing happens. Apps no longer have to ask you the classic Don’t Save/Save/Cancel question, because the document is automatically saved. Everything just works. It’s a huge boost for productivity and sanity, and—most important—eliminates that horrible moment when you click Don’t Save when you meant to click Save and lose all of your recent work.

But what if you choose to use the Save command tactically, only saving when you’re absolutely sure that you’re comfortable with the changes you’ve made to a document and don’t want to go back to your previous save? That’s where Versions comes in.

Versions is a bit like Time Machine: It’s an attempt by Apple to take geeky technology that’s been around for ages (in this case, the version-control systems used by programmers) and bring it to regular computer users. In fact, you can think of Versions as a sort of Time Machine for individual documents. When an app Auto Saves (or you give in to muscle memory and press Command-S), the system notes what’s been changed. A trail of past versions remains available at all times.

If an item you deleted yesterday has suddenly become important today, you choose Revert to Saved from the File menu, and enter Versions’ spacey Time Machine-style interface. On the left side of the screen is the current version of your document; on the right are all previous versions. If you think everything you’ve done in the document recently was a colossal mistake, you can navigate back to a previous version and click Restore to entirely replace your current version. If you only want to grab a snippet out of that previous version, you can do that too, by navigating back to a previous version, selecting the snippet, and just copying it out and pasting it into your current document.

Apple’s done a great job simplifying what could have been an extremely complicated process. The key, I think, is offering people the ability to select items from the old versions and just copy and paste them into the current version. I’m far more likely to want to retrieve a single paragraph from an old file than the entire thing, and Versions lets me do that in a way that’s just as easy as copying from one window in my app and pasting it into a different window.

Since Lion is launching before the arrival of Apple’s iCloud service, it’s unclear how Auto Save and Versions will interact with iCloud. Since they appear to have been designed in parallel, I’m hoping that apps will be able to Auto Save to iCloud and retrieve versions from iCloud as well. If “the truth is in the cloud,” as Steve Jobs said, then the cloud is the right place for your versions to live, too. But we’ll have to wait until iCloud arrives this fall to see how all the pieces fit together.

Resume

Apple seems intent on stamping out the idea that quitting or shutting down an app—or the Mac itself—is a little death, an attack of amnesia that makes that app or Mac forget where it was.

In Lion, if you quit an app with a bunch of open windows then re-launch it, all those open windows return, right where you left them. Coupled with Auto Save, Resume means that quitting and launching Mac apps in Lion is as seamless as quitting and launching iOS apps: they open back up right where you left off. (You can turn this feature off globally by going to the General pane in System Preferences and unchecking Restore Windows When Quitting and Re-opening Apps; you can also disable it temporarily by holding down the Shift key when you launch an app.)

This feature doesn’t work just with individual apps. Lion also keeps track of which apps are open when you shut down or restart your Mac. If you turn off your Mac with Mail, iCal, and TextEdit open, those three apps will be running, right where you left them, when you turn it back on. (You need to be patient about this: If you try to click on a restarted app before it’s ready to run, you’ll see the spinning-gear and a grayed-out window.)

If you consider Resume alongside the new behavior of the Dock—there’s now a System Preferences option to not include a dot under running apps—it’s clear that Apple is steering us toward a future in which we no longer think about turning apps on or off; rather, we’ll just switch between them just as we do on iPhones and iPads. That future isn’t here just yet; in Lion, you can still launch and quit apps. It’s just that they’re more resilient than they were before. And that dot is still on by default.

Resume is another feature that will make lots of sense to Mac novices, but will force more experienced Mac users to adapt. While I don’t like re-opening all my documents every time I quit an app, sometimes I want to start from scratch. Likewise, I’ve grown up in a Mac environment where only those apps you’ve specifically set to launch at startup do so; in Lion that’s no longer the case. After a few weeks of working with Lion, I’m becoming comfortable with Resume, but I’ve had to learn to close documents I never want to see again, rather than just quitting the app.

Inside the apps

Of course, there’s always more to OS X than the OS itself; there’s also all the apps Apple bundles with the system. In Lion, there have been major updates to Mail, iCal, Safari, iChat, Preview, and various other utilities. We’ll have separate reviews of many of them in the next few days. But in the meantime, my own quick reactions:

Mail A few months back I abandoned Mail for MailPlane ( ), frustrated by just how slow it seemed when interacting with my Gmail accounts. With the arrival of Lion (and after implementing Joe Kissell’s excellent instructions on configuring Mail and Google), I decided to give Mail another chance.

I’ve found the new version of Mail a big improvement. The new wide layout is a good fit for the displays on most Macs, something that previously required a plug-in such as Letterbox or WideMail. Searching for messages is more powerful now, thanks to the same easy-to-use search system found in the Finder. And Mail’s support for full-screen mode is solid; on my 11-inch MacBook Air, it’s the only app I consistently run that way.

But I think the best addition to Mail is support for a real conversation view, clustering related messages together so you can see the entire context of an e-mail thread. (That was probably the feature I appreciated most about Gmail.) If you wish (you have to enable it in Mail’s preferences), the app will pull all related messages (not just those in the current mailbox) into your view of the conversation. And Mail streamlines the conversation view by automatically hiding text quoted from earlier messages.

Safari Safari’s marquee new feature, Reading List, lets you save a Web page for reading later. It’s a concept that will be familiar to anyone who’s used the iOS app/web service Instapaper ( ). But it would be more accurate to say that Reading List is really just a friendlier version of old-fashioned bookmarking. I don’t think Reading List is a replacement for Instapaper because it saves URLs only, not the contents of pages. But it’s still better than bookmarking for keeping track of web pages that you want to read later.

Apple has also done away with Safari’s Downloads window, replacing it with a popover that appears when you click the Downloads button in the toolbar. I’d often keep Safari’s Downloads window open just to monitor the progress of a big download, but that’s no longer possible: the new Safari’s popover shows you the progress of downloads only from windows you still have open. There is one improvement, though: Downloaded items are now draggable. You no longer have to search for them in the Downloads folder in order to move them somewhere more useful; you can move from the Downloads window itself.

iChat With Lion, iChat has truly embraced its status as a multi-service chat utility. In addition to AIM, previous versions could connect to Google Talk and other servers using the Jabber protocol. But now the door is wide open: iChat supports Yahoo Messenger out of the box, and there’s a plug-in system that allows developers of other chat systems to add support for their services. There’s also a unified buddy list to bring all your friends on all those services together in one window; you can set a unified status message on all the systems you’re using. I’m primarily an AIM guy, even now, but I’m on some other services and will now use them more often. Here’s hoping that Microsoft Messenger (and Microsoft’s new purchase, Skype) join the iChat party soon.

What’s missing from iChat is a bit more confusing. The iMessage service announced by Apple as a part of iOS 5 will presumably debut with its release, but it would’ve been nice if Apple committed to supporting it within iChat as well. And of course FaceTime is still a separate app, even though iChat supports video chat itself. I’m still not sure why I need to run iChat and FaceTime simultaneously.

iCal The new version of iCal has gotten a makeover: The top of the iCal window has been given a leather texture with hints of torn-off pages beneath (the same design approach used on the iOS Calendar app), making it look a bit more like a paper calendar. It’s an unnecessary gimmick, sure—who uses tear-off paper desk calendars anymore, anyway?—but it's mostly harmless. I’m not sure why Apple has chosen to make a few of its apps mock their real-world counterparts, and the app would probably look better with a standard gray toolbar. Sometimes Apple’s ways are mysterious. (The functional part of the iCal interface has also been revamped, with the source list on the left side replaced with a popover in order to create more room for actual calendar data.)

The most notable new feature in iCal is support for natural-language event creation. Click on the plus-sign (+) button in the toolbar and, instead of an event pane, you get a blank text box. Type meet with Phil Tuesday at 4 and iCal will do its best to schedule that event; in this case, it’ll create an event called Meet with Phil on Tuesday at 4 p.m., and open it in the familiar iCal event pane for you to edit as needed. In testing, this approach worked well, though it’s not quite as flexible as a dedicated add-on like the excellent Fantastical ( ) or QuickCal.

And the rest

After more than 6000 words, I feel that I’ve still barely scratched the surface of what’s new in Lion. I’ve run through only some of the biggest, most obvious of those changes. Among the smaller ones that stand out:

AirDrop Need to transfer files between a couple of nearby Macs, but don’t have a USB keychain drive? AirDrop solves that problem, by letting two Macs connect to each other over Wi-Fi to quickly drop files back and forth. You don’t even have to be on the same Wi-Fi network for it to work, since AirDrop connects the two Macs directly (and without requiring the user to fuss with network settings). It’s meant to be a simple, easy-to-use file transfer mechanism, and it works. It’s a smart little feature that will save all sorts of time when you need to swap files quickly.

Security In some ways, OS X has fallen behind Windows in terms of security technology—mostly because Microsoft has had to defend Windows from the massive amount of malware the platform attracts. But Apple has introduced several security features in Lion, including increased memory randomization and iOS-style application sandboxing (which Mac App Store apps will be forced to support, eventually). I’m a little concerned about just how strong that sandbox needs to be—depending on how Apple enforces those rules, it has the potential to cripple the Mac platform. Familiar, functional Mac apps could potentially have to remove features in order to fit in Apple’s sandbox. We’ll have to see how it plays out over the next few months.

Apple is also adopting the iOS approach to file encryption. The new FileVault encrypts your entire drive. Once your drive is encrypted, you can instantly wipe its data just by telling the system to delete the decryption key; that’s the same technique used to wipe iOS devices. When you’re not logged in, the data on your drive is inaccessible. It sounds like a good idea, and much more of a holistic approach than the original disk-image-based FileVault. I worry about users who might encrypt their data but then lose the key (through mental or technical error). Apple is trying to reduce that risk by generating a recovery key that you can store in a safe place, separate from your password.

Apple IDs everywhere It used to be your iTunes ID, but it’s now an Apple ID. This fall, it’ll work with iCloud. And in Lion, it’s more versatile. If you want to grant someone file-sharing access to your Mac, you don’t have to create a new user: just enter the person’s Apple ID and they can log in using that; same goes for Screen Sharing. And AirDrop uses Apple IDs to verify the identities of other users. Apple’s on a mission to get that Apple ID in every crevice of its ecosystem.

Screen Sharing As someone who keeps a Mac mini in a closet as a server, I use the Screen Sharing app a lot. It’s gotten a few nifty improvements, my favorite being the ability to log in as one user on a remote Mac while a different user is logged in locally. I love the idea of quickly popping into my home iMac and moving a few files around without making my wife log out first.

AppleScript and Automator Fans of scripts and workflows will be happy to know there are upgrades to both AppleScript and Automator. AppleScripts can now access all the Cocoa frameworks, offering huge power to scripters who learn even the most basic Cocoa tricks. Some cool new services are installed by default, including the ability to convert videos into formats that are consumable by iOS devices and auto-generation of ePub-format ebooks. And installing Automator actions and services just got a lot easier—when you double-click on them, the system offers to move them to the right place for you.

Resize anywhere Apple’s given in to the Windows convention: you can now resize a window from any side, not just the bottom-right corner. This eliminates the small shaded area in the corner of every window. After using the bottom-right corner to resize windows for the past two decades, it’s going to take me some time to adjust to this.

Restore partition When you install Lion, the system automatically creates a special startup partition on your hard drive. This means that, if something messes up the contents of your hard drive (but doesn’t physically damage the drive), you can reboot, hold down the Option key, and then boot into the restore partition. From there you can run Disk Utility, reinstall Lion, wipe the drive and restore from a Time Machine volume, or even load up Safari and browse the Web for troubleshooting advice. It’s not a feature that will help you in the event of a catastrophic hardware failure, but it’s a great backup for those times when the contents of your drive get hinky.

Is it stable?

I've been using the final version of Lion for weeks now and have seen very few bugs. It's been a comfortable ride. That said, this is Mac OS X version 10.7.0—note the zero at the end. If you are someone who wants to try out the cool new features of Lion today, by all means take the plunge. But back up your drive first, in case you need to fall back to Snow Leopard. And on systems where you do critical and time-sensitive work, you might be best advised to wait a little while until the developers of your most vital apps certify that they're good to go with Lion. No new system release is without its quirks. As stable as this release has been for me, it's a major update and you should proceed with caution. I've upgraded my work iMac and my MacBook Air to Lion; the home iMac that my wife and kids use will remain at Snow Leopard for a little while longer, just in case.

Macworld’s buying advice

After a long period of relative stability on the Mac, Lion is a shock to the system. It's a radical revision, motivated in part by the vast influx of new Mac users coming to the platform from iOS, that makes the Mac a friendlier computer. Veteran Mac users who don’t like those changes can turn many of them off, or just opt not to use them.

Auto Save, Versions, and Resume should together reduce the amount of time you spend managing files, so you can focus on the more important task of actually using them. Mission Control sweeps several window-management initiatives into a more cohesive whole. The new search system in Finder and Mail is so good you’ll wish it was in Spotlight too. Finder’s All My Files view is a handy way to quickly get a grasp on what’s new and changed on your Mac. Mail’s upgrade is impressive, especially its expanded view of conversations and related messages.

On the downside, Launchpad owes a bit too much to the iOS, limiting its utility, and it’s too hard to organize apps. Full-screen apps have potential, but only if developers embrace the format and truly re-invent their interfaces; even then, users of multiple monitors will find that those interfaces waste perfectly good screen-space. And Apple’s reliance on a downloaded installer app causes needless complications, especially when a hard drive dies.

Can novice users fresh from the Apple Store and grizzled Mac vets who have been pounding out Terminal commands since 2001 share one operating system without driving each other crazy? It’s an interesting question. With Lion, Apple seems to be doing a fine job of adding novice features without making them too maddening for more comfortable users. That’s good, because novices become veterans over time.

In the past, Apple has charged $129 for upgrades with far fewer improvements than this—and that price upgraded just a single system. At $30 for all the Macs in your world, the only reason not to upgrade to Lion is because you rely on old PowerPC-based apps that won’t run on it. Otherwise, it’s a more than fair price for a great upgrade.

[Jason Snell is Macworld’s Editorial Director.]