I’m writing some library code at the moment that needs to work on both Mac OS X and iOS. The APIs I need to use on each platform are different, so I need different code on each platform. I also happen to think that putting both versions of the code in the same implementation file is icky.

A Cocoa controller class for Sheets that replaces the completion callback method with an inline block.

RFAnimatedSlider is a subclass and drop-in replacement NSSlider that uses CoreAnimation to animate between states. It looks exactly like NSSlider because it uses the same drawing routines.

NSLogger is a high perfomance logging utility which displays traces emitted by client applications running on Mac OS X or iOS (iPhone OS). It replaces your usual NSLog()-based traces and provides powerful additions like display filtering, image and binary logging, traces buffering, timing information, etc.

It is similar in concept to other popular logging frameworks such as log4j, yet is designed specifically for objective-c, and takes advantage of features such as multi-threading, grand central dispatch (if available), lockless atomic operations, and the dynamic nature of the objective-c runtime.