Mac OS X Lion

Mac OS X Lion, or Mac OS X 10.7, is the eighth major release of the Mac OS X operating system released on 20 July 2011. It was announced on 20 October 2010 at Apple's Back to the Mac event. This version dropped support for the x86 userland and architecture and removed Rosetta and Front Row. It introduced the Launchpad and was originally only released as an App Store update that could only be updated normally from Snow Leopard.

It is the first version of Mac OS X to not be distributed on optical discs as it was released as an online-only download through the Mac App Store. Although, Apple would later release a USB flash drive containing the installation image in August 2011.

It is the last version to be released under the Mac OS X name as the operating system's branding was shortened to OS X starting with the release of OS X Mountain Lion in 2012. It is also the last version of Mac OS X to be released under the old release schedule in which every version of Mac OS X was released every two years as the operating system shifted to a new annual update schedule starting with the aforementioned version.

New features and changes

 * The Launchpad has been added. It is an application launcher that features a design similar to the iOS home screen. The user can add multiple pages and can create folders to organize apps in.
 * Multi-touch gestures have been added.
 * The ability to save and browse past versions of documents for applications in a Time Machine like UI has been added.
 * A later update in October 2011 added iCloud support, replacing the MobileMe settings applet.
 * The Address Book received an iPad-like UI. It adds improved support for Yahoo! and FaceTime calling.
 * The AirDrop file sharing technology has been added. It allows two Macs running Mac OS X Lion to share and send files via Wi-Fi Direct.
 * ASLR has been added which puts important data in unpredictable parts of the system, making it harder to target known weaknesses.
 * Support for the Apple Push Notification Service has been added which sends over-the-air alerts.
 * Auto-correction was changed to have an iOS-like popup box.
 * Auto Save has been added. It allows compatible applications to automatically save the current document.
 * Support for Emoji has been added.
 * The FaceTime app was added.
 * FileVault now supports full disk encryption. It also now supports external hard drives.
 * Various improvements to Finder.
 * Added Font Book 3.
 * Native system-wide support for full-screen applications was added.
 * Added more high-quality Multilingual speech voices
 * The iCal app received an updated UI and now has an annual view and support for full-screen.
 * iChat adds support for Yahoo! Messenger.
 * Arabic, Czech, Turkish and Hungarian languages have been added.
 * The Mail app now has an iPad-like UI, supports full-screen and adds support for Exchange 2010.
 * Mission Control has been added to replace the All windows Exposé feature and combines Exposé Dashboard and Spaces into one single view. It gives an overview of all running applications on the system.
 * Support for Multi-User screen sharing has been added.
 * Preview gained full-screen support and several new features.
 * The Profile Manager adds several new features including push notification based management.
 * The Recovery Partition is now installed alongside the rest of the OS.
 * The Resume feature allows for suspending applications.
 * Safari gained full-screen support along with numerous improvements.
 * System Profiler has been redesigned and renamed to System Information.
 * Terminal gained several new features including full screen support.
 * TextEdit has a new toolbar and supports Auto Save.
 * Elements of the Aqua UI including buttons, progress bars and the metal finish of windows have been redesigned.
 * Window resizing has been made more flexible.
 * The scrollbar arrows have been removed.
 * The animations for opening and resizing apps have been changed.
 * The texture of selected tabs have been changed to a recessed and darkened appearance.
 * The Dashboard is now in its own space in Mission Control. The user can return to the old Dashboard configuration in System Preferences.

Removed features

 * Save As has been replaced by the Duplicate and Revert actions.
 * Front Row has been removed.
 * Rosetta is no longer available which means that PowerPC applications can no longer be executed.
 * Adobe Flash Player and JRE are no longer included by default.
 * iSync has been removed.
 * Remote Install Mac OS X has been removed in favor of the Recovery Partition.
 * The Welcome Video after install has been removed.