Xcode provides everything developers need to create great applications for Mac, iPhone, and iPad. Xcode 4 has been streamlined to help you write better apps. It has unified user interface design, coding, testing, and debugging all within a single window. The Xcode IDE analyzes the details of your project to identify mistakes in both syntax and logic, it can even help fix your code for you.
What's New In This Version:
SDKs for OS X 10.8 Mountain Lion and iOS 6.
Auto Layout now supported on both OS X and iOS.
New localization workflow can share a single base .xib or .storyboard file for multiple locales.
OpenGL debugger for iOS analyzes performance and suggests improvements.
Debugger watchpoints can be set when running on a connected iOS device.
Objective-C @synthesize command is generated by default when using properties.
Objective-C adds literal syntax for numbers, arrays, dictionaries, and expressions.
Xcode 4.5 runs on both OS X Lion and OS X Mountain Lion.
Enhanced for the MacBook Pro with Retina display.
Additional bug fixes and stability improvements.
You can download Xcode from the App Store for free.