Apple released not only a preview version of Lion Mountain, but also a new version of Xcode (4.3) which is now available as a standalone app in the Mac App Store. This version replaces the Install Xcode package and adds support for delta updates. Xcode 4.3 also has a new "Downloads" preference pane that lets you install optional components, such as command line tools and previous iOS Simulators.

Xcode 4.3 in the Mac App Store includes the OS X 10.7.3 SDK and iOS 5 SDK. If you are developing iOS 5.1 apps, you should continue to use Xcode 4.3 Developer Preview with iOS 5.1 SDK beta, available in the iOS Dev Center.

Xcode provides everything developers need to create applications for Mac, iPhone, and iPad. Xcode has unified user interface design, coding, testing, and debugging all within a single window. The Xcode IDE analyzes the details of the project to identify mistakes in both syntax and logic, it can even help fix the code.

Here's what's new in version 4.3:

• Includes SDKs for Mac OS X 10.7 Lion and iOS 5
• New code signing workflow supports signing OS X apps with Developer ID
• Adds installation of command-line tools to the Downloads preference pane
• Open Developer Tool menu launches Instruments, File Merge, and other tools
• ARC migration tool converts both retain/release and garbage collected code
• Additional bug fixes and stability improvements

In order to download Xcode 4.3 for Mac, follow this link.

Source: http://itunes.apple.com