Apple yesterday released a second developer preview version of Xcode 4 via its developer site, also posting a significant amount of new information about the release on its site. Xcode 4 brings a significant overhaul to Apple's tools for building Mac OS X and iOS applications, including a transition to a single-window application with Interface Builder integrated directly into Xcode.
Xcode is the complete toolset for building Mac, iPhone, and iPad applications - and with Xcode 4, the tools have been redesigned to be faster, easier to use, and more helpful than ever before. The Xcode IDE understands your project's every detail, identifies mistakes in both syntax and logic, and will even fix your code for you. Quite simply, Xcode 4 will help you write better code.
Xcode 4 has a brand new user interface, built upon proven technologies that Apple itself uses to build Mac OS X and iOS, and that have produced over a quarter million Mac, iPhone, and iPad apps.