"The end result is that, with zombies enabled, messages to deallocated objects will no longer behave strangely or crash in difficult-to-understand ways, but will instead log a message and die in a predictable and debugger-breakpointable way. This is the tool to use when trying to track down over-releases and premature releases."

"Over the past decade, better technology has simply reduced the number of things that we need to care about. Lion is better technology. It marks the point where Mac OS X releases stop being defined by what's been added. From now on, Mac OS X should be judged by what's been removed."

Screen recording for Mac OS X.

The Core Animation-based UI framework used in Twitter for Mac.

From Macworld 2011.