Mac OS X Lion (10.7)

 Mac OS X Lion (version 10.7) is set to be the eighth major release of Mac OS X, Apple's desktop and server operating system for Macintosh computers. Mac OS X Lion is set to be released in summer of 2011.
A preview of Lion was publicly unveiled at Apple's "Back to the Mac" event on October 20, 2010. It will bring many developments made in Apple's iOS, such as an easily-navigable display of installed applications, to the Mac, and will include support for the Mac App Store, as introduced in Mac OS X Snow Leopard version 10.6.6. On February 24, 2011, a developer's preview of Lion (11A390) was released to subscribers of Apple's developers program.

Hardware Support
The first developer preview of Lion added TRIM support for solid-state drives (SSDs) shipped with Macs, which is also included in the latest build of Snow Leopard shipping with current MacBook Pros. As of yet, there is no TRIM support for other SSDs.  

System Requirements

• x86-64 processor (Macs with an Intel Core 2 Duo or later CPU)
• DVD drive (also accessible via Remote Disc) or external USB or FireWire DVD drive for installation (however, the February 2011 developer preview can be installed directly from its disk image on a local or networked volume)

New or changed features

Some new features were announced at the "Back to the Mac" keynote in October 2010, and the Apple website was updated in February 2011 with more details. More features are expected to be revealed as the release date nears.

• Address Book now uses an iPad-like user interface.
• Auto Correct - Auto correct now behaves much like on iOS devices, even displaying an iOS like popup box.
• AirDrop — Mac-to-Mac file sharing.
• Auto Save — As in iOS, documents in applications written to use Auto Save will be saved automatically so users don't have to worry about manually managing their documents.
• FaceTime comes bundled with Lion.
• FileVault now offers full disk encryption added security with XTS-AES 128 data encryption. Support for FileVault on external hard drives has also been added.
• Finder redesigned.
• Folder Merging — Unlike previous versions of OS X, one can now merge files under two folders with the same name. A prompt will appear asking whether one wants to replace or keep both files.
• iCal has an updated user interface, with support for a full-screen view.
• iChat support for logging into Yahoo! Messenger. Users can audio- and video-chat with other iChat users using their Yahoo! accounts.
• Launchpad — An application launcher that displays an iOS-like icon grid of installed applications. It will feature the ability to make multiple pages and group apps into folders which function the same as folders in iOS.
• Mac App Store — An application store built in the image of the iOS App Store. Like in iOS, it will provide ways for shoppers to discover apps, one-click installation of apps, and one-click updates of all or selected installed applications. Despite being announced as a future feature of Lion, the Mac App Store was released for Mac OS X Snow Leopard on January 6, 2011 as it was bundled with the Mac OS X 10.6.6 update.
• Mail 5 – Uses an iPad-like user interface, has a fullscreen-optimized view, uses chronological "Conversations" to organize messages, and supports Exchange 2010.
• Preview gains several features, including full-screen support and the ability to sign a document just by holding a signed piece of paper up to the camera.
• Profile Manager — Allows profile-based management of iOS devices and Mac OS X Lion
• QuickTime re-incorporates some features from QuickTime Pro. New features cited include Copy/Paste, Insert Clip, Crop Video, Rotate Video, Resize, Trim, and more Export options.
• Recovery Partition — Apple has introduced a recovery partition that includes utilities generally found on the OS X discs. This partition will allow the user to restore their computer to its original factory state.
• Resume — Applications resume in the same state when re-opened as already seen in iOS. Because of this, the Dock no longer visually indicates whether an app is currently running or not by default - the original behavior can be restored in the Dock section of System Preferences.
• Safari with full-screen mode and the new WebKit 2 layout engine.
• Server — Mac OS X Server is now bundled with Mac OS X, rather than being a separate version of the OS.
• System Information — This feature is a re-design of "About This Mac" and has been completely altered with new views which display graphical information on displays, storage devices, memory usage along with other hardware information.
• Versions — Time Machine-like saving and browsing of past versions of documents for applications written to use Versions.

Refinements to the user interface

• Full-screen apps — Native, system-wide support for full-screen applications. Supporting applications display a new button at the top right of application window, this button opens applications in full-screen mode.
  
• Mission Control replaces the "All windows" Exposé feature. It gives an overview of all running applications just like "All windows" but groups windows from the same application. At the top of the screen it gives quick access to the Dashboard, Spaces, and running full screen applications.
• Multi-touch gestures — Similar to iOS, additional gestures performed using a multi-touch input device (e.g. Magic Mouse, Magic Trackpad) will allow the user to scroll, swipe to different pages, and enter Mission Control. While this is not the first official multi-touch support for Mac OS X, it has been expanded; other frameworks, such as Lux, have already created multi-touch support.
• Many changes to the user interface include:
  • Redesigned Aqua user interface elements, button, tabs are now "sliding switches", progress bar. The red, yellow, and green close, minimize, and maximize buttons in the window decorations have been made smaller.
    
  • Flexible window resizing from any corner or edge of the window.
  • The metal finish has also been slightly altered. It is now a lighter shade of grey than before and features a speckled texture.
    
  • By default, the dock no longer displays active application indicators.
    
  • Scroll bars now disappear by default when they are not being used, similar to iOS. ProperApple APIs must be used in order for iOS-styled scroll bars to appear.
    
  • Scrolling is reversed by default, to act more like a touch screen computer. (Content moves in the direction of finger movement on touch-pad or mouse)
    
  • When resizing a window by clicking on the green button (left-top), a transform-effect animates the enlargement.
    
  • New windows fly to the front (like opening a program in iOS).
    

Dropped features

• Front Row
• A Java Runtime Environment (JRE) is no longer installed by default, but can be installed on demand.
• Adobe Flash Player is no longer installed by default and must be installed manually.
  
• Rosetta, software which makes possible the execution of PowerPC software on x86 hardware, is no longer available.