PLIST Editor is an easy to use editor for property list (.plist) data. In a clean and uncluttered interface, it allows you to quickly create, visualise, modify, and save your .plist documents.
Developer Tools
TextMate brings Apple's approach to operating systems into the world of text editors. By bridging UNIX underpinnings and GUI, TextMate cherry-picks the best of both worlds to the benefit of expert scripters and novice users alike. (MacroMates.com Home Page)
TextMate is a simple yet robust text editor that supports a vast array of languages from simple plain text to HTML to ObjectiveC. An application that supports the SVN and Git repositories and supports bundling so you can add your own or other support for other languages or modified languages.
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.
Xcode runs on OS X Lion and includes the Xcode IDE, Instruments, iOS Simulator, the latest Mac OS X and iOS SDKs, and hundreds of powerful features: