Xcode 4 is probably the most significant change to Apple's developer tools since they were released. Ars provides a short overview of the changes, and highly recommends you RTFM if you're going to use this software.
<a href='http://meincmagazine.com/apple/reviews/2011/03/xcode-4-hands-on.ars'>Read the whole story</a>
<a href='http://meincmagazine.com/apple/reviews/2011/03/xcode-4-hands-on.ars'>Read the whole story</a>