Apple has released Mac OS X Lion Golden Master version for developers. You can download it if you are a registered member of Apple’s developers program. This is the pre-release of next major update of Mac OS X.
Mac OS Lion build 11A511 is available for download from Apple’s Mac Developer site. Mac OS Lion will bring tons of new features, enhancements, security and bug fixes and support for new hardware. The most important features from developers point of view include:
Mac App Store
Mac OS X Lion includes the Mac App Store — the best place for users to discover, purchase, and download your apps. Millions of customers in over 90 countries can quickly and easily select from some of the best Mac apps conveniently on their Mac. Learn more about the Mac App Store and how you can introduce your apps to millions of users around the world.
Full Screen Apps
Provide an immersive, focused user experience with a full screen app. NSApplication, NSWindow, and the NSWindowDelegate Protocol in Mac OS X Lion make it easy for you to create and manage full-screen user interfaces while providing you the power to design rich user interactions.
Aqua defines the look and feel that users come to expect from Mac OS X. Lion takes this experience and brings it to a new level with popovers, overlay scrollbars, and powerful Multi-Touch gestures and animations.
AppKit framework now includes popovers, a new unit of content that can be positioned relative to other content on the screen. Popovers automatically move whenever the positioning view moves. You can also design popovers that can be detached, allowing them to become a separate window.
Mac OS X Lion introduces overlay scrollbars similar to those in iOS. These scrollbars appear as an overlay on top of the window’s content while the user is scrolling and remain visible briefly to allow scrollbar dragging.
Multi-Touch Gestures and Animations
The fluid, responsive animations that create the magical user experience on iPad and iPhone are available in Mac OS X Lion. Design your apps to use Multi-Touch gestures and animations and redefine the interaction users have with your apps.
AV Foundation framework provides essential services for working with time-based audiovisual media. Through an Objective-C interface, you can easily play, examine and compose audiovisual media in your app. An array of powerful classes also make it simple to edit and encode media files. You can even capture audio and video from external devices and manipulate them in realtime.
Auto Save and Versions
If you have a document-based application, Lion offers an efficient, built-in auto save feature that stores changes to the working document instead of creating additional copies on a disk. Versions automatically records a history of changes made to your documents and lets your app display a Time Machine like interface so users can browse through previous versions.
Resume in Lion allows users to restore your app exactly where they were prior to logging out or restarting. Apps that were last running launch automatically and all open document windows return to where they were. The system automatically manages apps and conserves resources by closing apps that are not being used.
Sandboxing and Privilege Separation
Create apps that are more secure with app sandboxing and privilege separation. Sandboxing protects the system by limiting the kinds of things an application can do, such as accessing files on disk or resources over the network. Limiting the capabilities of an app to just those operations that it needs to perform helps keep the rest of the system more secure in the event that an app is compromised. Privilege separation is another common technique for improving security where an app is factored into smaller pieces, each with their own distinct roles and privileges.
Coordinating access to files between multiple threads and multiple processes can be difficult and error prone. File Coordination helps eliminate inconsistencies due to overlapping reads and writes by allowing your application to access files and directories in a way that is serialized with respect to other processes’ accesses of the same files and directories.
The end users may receive the public version any time next month which will be available through Mac’s App Store. If you are planning to get Lion on your machine, you should install the latest Mac OS X 10.6.8 update which prepares your device for this major release.