How can I show xib directly in xcode enviroment?

I've been reading articles at raywenderlich.com and saw that they show an XIB being edited in Xcode directly:

http://i.开发者_如何学编程stack.imgur.com/aCTSF.jpg

How can do this in Xcode?

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That is a new feature of XCode 4 and onwards. If you have the Apple Developer Membership, you can download it at http://developer.apple.com/xcode/.

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this is new version of xcode just download & install it :) u will have same editor in it :)