Open Transport Gone
Some of you will be surprised to hear that Open Transport was included through OS X 10.8. Most of you probably have no idea what Open Transport is (was). (It was a set of flexible, stream-based networking APIs from the pre-OS-X era.)
What’s New in OS X lists some removed APIs: Open Transport, Power management (Power.h), Message.framework, ServerNotification.framework.
This affects almost nobody. But it does affect some people.
Newly-deprecated: InstantMessage.framework, Quicktime.framework, QTKit.framework. (Superseded by Social.framework and AVKit and AVFoundation.)