updated 09:00 pm EST, Thu February 16, 2012
New version will not auto-update
In a further move to support use of the Mac App Store for developers, the company has issued a new version of XCode as a free Mac App Store standalone application. The new version, 4.3, is for Lion developers and not the same as the v4.4 that was released earlier today with the developer preview of Mountain Lion. The new version replaces the previous XCode and adds support for delta updates among other changes.
The update process for the new version is more awkward than normal due to the new support for MAS updating and delta updates. Developers will need to visit the MAS page directly and download the new package, as it will not show up as a Mac App Store update in the "Updates" section. Once installed, updates will work as normal going forward.
The new version also sports a new "downloads" preference panel for installing optional components such as command line tools and older-version iOS simulators. The application now requires Mac OS X 10.7.3, and includes SDKs for Lion. The app is publicly available for anyone to try, but in order to deploy apps or test iOS apps using the simulator, users must be a registered member of Apple's Developer program.
XCode 4.3 also sports several new changes, including support for code signing with developer ID, an ARC migration tool that converts both retain/release and garbage collection codings, as well as an Open Developer Tool that launches Instruments, File Merge and other tools.