Updated: Mac OS X 10.7 Lion features explained ~ Share Hacker

After a demo in February and a preview version too, we've now got full details on Apple's new OS from the Apple Worldwide Developers' Conference taking place this week in San Francisco
The OS was originally announced back in October 2010, OS X 10.7 Lion has taken some of what makes iOS great and updated for the desktop.
Announcing Lion at the Autumn 2010 keynote, Steve Jobs said the new OS would bring features developed for iOS back to the Mac. "We started with Mac OS X, repurposed it for the iPhone and used it in the iPad as well," he explained. "Now we're bringing some of its ideas back to the Mac."
Today's announcement sees over 250 new features added to the OS, with Apple's Phil Schiller showing off ten key features at WWDC today, including fullscreen applications and multi-touch gestures.

So what OS X 10.7 features will we see?
MacOS X 10.7 Lion UK release date
The Mac OS X Lion 10.7 release date is in July and is available from the Mac AppStore as a 4GB download to all your authorised Macs. Yep, that's right - MacOS X goes disc-free!
MacOS X 10.7 Lion UK price
OS X Lion will cost $29.99 in the US. We're not yet sure what theMacOS X 10.7 Lion UK pricing will be, but we'd expect it to cost £29.
MacOS X 10.7 Lion multi-touch
Lion will be fully multi-touch compatible - all Macs now have multi-touch trackpads while for desktop Macs there's also the Magic Trackpad of course. Mac sales are three quarters notebooks at the moment. The scrollbars in Mac OS X Lion.
Scrollbars simply disappear when you are using gestures, while there's tap-to-zoom, pinching and two-finger swiping. Apple's Phil Schiller says it works "with an incredible, physical realism never been possible in a PC operating system before."
Mac OS X 10.7 Lion is inspired by iOS
There's a new Launchpad in iOS - this is an app launcher that works just like the homescreen in iOS.When you open Launchpad, open windows fade away to be replaced by a grid of application icons, just like you see on your iPad, iPhone or iPod touch. You can rearrange their position by dragging icons to different locations, and group them in virtual folders. And as with iOS, multiple pages of apps can be navigated with a swipe gesture.
Mac OS X 10.7 Lion fullscreen apps
Another feature making its way from iOS to Mac OS is fullscreen applications. With a single click, apps written to take advantage of this feature can fill the entire screen, with no borders or distractions. You can swipe between fullscreen applications and the desktop to use your apps that are not being viewed fullscreen.
Naturally, iLife and OS X-native apps such as iCal, iPhoto, Preview and Mail will have a fullscreen option, and system-wide support allows third party developers to include the feature in their own applications.
Mac OS X 10.7 Lion Mission Control
Mission Control combines Exposé, Spaces and Dashboard into a single feature, giving an overview of everything that's open on your Mac. Mission Control groups open windows according to the application in which they're running, making it much easier to find what you're looking for. As such, thumbnails of Spaces-style virtual desktops and fullscreen apps are shown across the top of the screen, along with the Dashboard. You can swipe between apps even in full screen and exit them using a control in the top right.
Mac OS X 10.7 Lion auto-save
The way OS X saves your work has undergone a revision, with two new features added for Lion. Instead of pressing Command+S every couple of minutes, saving is automatic in OS X 10.7.
It does more than simply save a backup copy as you go, like Microsoft Word and TextEdit do already. Instead, it saves the changes that have been made to a document instead of saving the file in its entirety, so it doesn't waste disk space. You can lock a document to prevent changes being auto-saved, and documents are automatically locked after two weeks.
The Auto Save feature is only available in applications written to take advantage of it, so remember to manually save documents created in non-autosaving apps.
Mac OS X 10.7 Lion Versions
The second new save feature, Versions, creates a history of a document as you work on it. A copy is automatically saved every hour and each time you open it (as well as manually whenever you wish). You can revert to a saved version of your document using a Time Machine-like interface, or simply open an older version and copy something you regret editing out, pasting it into the current document. You can access the different versions of the document via the document's name in the title bar.
Mac OS X 10.7 Lion Resume
If you've ever put off installing a software update as you didn't want the hassle of restarting your Mac while in the middle of something, you'll definitely welcome Lion's new Resume feature. When a Lion Mac restarts, it returns to exactly the same state it was in before it shut down.
Running applications relaunch and open windows reopen. It's so comprehensive that if you highlighted text in an open document or app, it's highlighted again on restart. This will prove incredibly useful, and a major timesaver; no need to save your work, close everything down and then relaunch it all after boot-up. With Lion, it's all done automatically.
Like fullscreen apps and Auto Save, Resume is only available in (to use Apple's term) "apps that have been developed to work with Lion". Third-party developers will no doubt welcome the opportunity to take advantage of these exciting system features, but it remains to be seen how fast software will absorb another level of OS integration.
Mac OS X 10.7 Lion AirDrop
AirDrop is an exciting but limited transfer system that works over Wi-Fi. By clicking the AirDrop icon in your Finder sidebar, you're shown every nearby Mac that's also using AirDrop. If someone in your Address Book runs the Mac, the photo associated with the profile is also shown. To send someone a file or folder, you simply drag it onto his or her name.
AirDrop is peer-to-peer, connecting via Wi-Fi regardless of whether the Macs are on the same network. Transferred files are saved to the recipient's Downloads folder, but only after being accepted; you can't copy something to someone else's Mac without their knowledge and permission.
Unfortunately, AirDrop is only for Macs running Lion. You can't, for example, transfer a file from your Lion iMac to a colleague's Snow Leopard MacBook Pro, and you certainly can't AirDrop to a PC - surely you will be able to use it with iOS in due course though. But if you're in a mixed Mac-PC environment or not all local Macs run the latest version of the operating system, you'll have to stick with Dropbox or USB flash drives.
Mac OS X Lion 10.7 App revisions
Mission control
Lion sees OS X's native applications revised. Address Book now resembles a physical book like the iPad version, with contacts listed on the left-hand page and individual contact details on the right. An icon disguised as a red bookmark ribbon is used to access your groups.
The change hasn't been met with universal enthusiasm. The current version of Address Book offers a three-pane view, with groups, contacts and details readily available. Switching to two panels for no better reason than to preserve a visual metaphor might be considered a backwards step.
An option to return to 'Classic Window' has been found in a debug menu; we hope it's available as a Preferences option for the final release.
Mac OS X Lion 10.7 Mail
Another OS X app that's adopted the look and feel of its iOS counterpart is Mail. The new version, Mail 5, makes much better use of its window space, showing a list of messages in your inbox and a full-height preview of the selected message. There's also a Favourites bar. A new Conversation View lets you thread messages from the same conversation in a timeline, even if the email's subject is changed. This makes an email exchange as easy to follow as a forum or newsgroup thread. Searching is also much improved.
Mail 5 is compatible with Microsoft Exchange Server 2010, and incorporates a powerful new search feature. Also, instead of a single flag to indicate an important message, you now have several coloured flags to choose from. This could prove useful if you want to flag different messages for different reasons or levels of priority.
QuickTime Player gains some features previously present in the paid-for Pro version of the application. You can copy and paste, insert a clip, crop, trim or rotate a video and resize your movie. Video sharing is built in, enabling you to export footage to MobileMe, Facebook, YouTube, Flickr, Vimeo, iTunes and Mail.
Screen recording is enhanced, allowing you to record a section of the screen simply by selecting it with your mouse.
Signed for Preview has a very interesting new feature. Signature Capture digitises your pen-and-ink signature for use in documents and emails. You simply hold the paper version in front of your Mac's webcam and your signature is captured.
iCal has picked up a few features from the iPad version, and also a Year view alongside Day, Week and Month. Its layout has been simplified, with a very clean and tidy user interface.
iChat has also undergone a minor revision, with support for Yahoo! Messenger added.
Mac OS X Lion 10.7 Safari improvements
Finally, Safari benefits from Apple's new WebKit2 engine, making it faster and more stable. Codewise, each open tab stands alone like a separate app, so if a web page crashes, it doesn't take down the whole browser.
Unsurprisingly, much use is made of system-wide Gestures. They're so widely used and well integrated into Lion, we wonder how comfortable the new OS will be without them. Will those who use a desktop Mac without a Magic Mouse or Magic Trackpad feel they're missing out?
Developers with access to the Lion preview have complained that the vertical scrolling gesture on a trackpad has been reversed to match the iPad's. Previously, moving your fingers down on a trackpad scrolled the window downwards, matching the actions of a mouse's scroll wheel. Now it scrolls upwards, like on iOS devices where you interact with the window more directly. This could get very confusing. We hope it's optional in the final build.
There are some notable changes in Finder, the Aqua interface and the system in general. With Lion you can resize a window with all four corners, not just the bottom-right. Lion's scroll bars are similar to those in iOS, appearing when needed and fading after use.
Finder windows include a new sidebar option called All My Files. This gives you a handy overview of every file on your Mac, which you can then order according to date, kind, size, name and more. Interestingly, if you take a close look at the icon – a drawer full of documents – several of them show quotes from Steve Jobs.
OS X's popular Quick Look feature has been expanded. Spotlight search results can be previewed, as can URLs sent to you in Mail or iChat. You can also Quick Look within Stacks. Unfortunately, there appear to be no tabbed Finder windows, a feature we hoped would be introduced in OS X 10.7.
Mac OS X Lion 10.7 security and FileVault 2
On a technical level, the FileVault 2 security option now encrypts your entire hard drive, not just the Home folder. It encrypts as you work and decrypts on the fly using XTSAES 128 data encryption; we're promised it's totally unintrusive.
A recovery partition containing utilities found on OS X install discs can be used to restart your Mac after a particularly bad crash without having to boot from the optical drive, and SSD TRIM support has been added to keep solid-state drives optimised.
Perhaps most significantly, the server edition of Lion is incorporated into the client version. As Snow Leopard's Server Edition is sold separately for £417, this represents quite a saving for those who want to set up a Mac purely as a server.
A few features have fallen by the wayside. The developer preview of OS X 10.7 has no Front Row, so if you want to use a media centre with Lion, you have to install a third-party application such as Plex or XMBC.
Adobe Flash Player and Java Runtime are no longer installed by default but can be added manually, and the translation bridge Rosetta has gone entirely, with no option for it to be installed. Without it, applications written for the PowerPC architecture cannot run on Intel Macs.
If you open the System Profiler found in Applications > Utilities, click on Applications and sort them according to Kind, you can see what (if any) PowerPC apps you have on your Mac. If you're planning to upgrade to Lion, they must be upgraded or abandoned.
Mac OS X 10.7 Lion is Intel-only
Like Snow Leopard, Lion is Intel-only. The developer preview demands an Intel Core 2 Duo processor or later, though the full system requirements have not yet been released, and are subject to change before the final version is with us.
Mac OS X 10.7 Lion is shaping up to be an excellent release. With powerful and practical new features and some welcome polish on existing ones, it seems set to radically change the way we use our Macs. We may not have been excited when it was first announced, but we certainly are now.
Other Mac OS X Lion 10.7 features
Apple says there are 3,000 new APIs as well as aWindows Migration assistant, FaceTime built in, plus a Lion Server add-on.