After iOS 4.2.6, iOS 4.3 beta 3, a new beta version of Mac OS X, Apple has also released Xcode 4 GM for developers. This is the last version before the release of the final one, so what you find available now is likely to remain permanently in the Xcode suite. Here's what's new in this version of Xcode 4.
- Xcode 4 has a brand new, single window interface for all major workflows
- Interface Builder is now integrated within the main Xcode IDE
- Assistant shows a paired editor with complementary files (headers, UI controllers, etc.)
- Fix-it highlights code where an error is detected, as you type, and can even fix it for you
- Version editor shows a live comparison through SCM history, using Git or Subversion
- LLVM compiler 2.0 includes full support for C, Objective-C, and now C++
- LLDB debugger is faster, and uses less memory than the GDB debugging engine (see notes below on how to enable the LLVM compiler or LLDB) debugger
- Instruments adds System Trace, and new iOS instruments including OpenGL ES
UPDATED: Xcode 4 GM was retired by Apple shortly after publication because it could only be installed on Mac OS X 10.7 Lion. On this occasion we will see some new rumors regarding the release of Mac OS X 10.7 Lion.
