Objective-C wrapper for Grand Central Dispatch (GCD)

Martin Kiss released an open source Objective-C wrapper for Grand Central Dispatch, which includes the following additions:

Detection of Current Queue using dispatch_get_specific.
Deadlock-safe -sync: method.
Convenience initializer for reverse-DNS label.
Accessors for Main Queue and Global Concurrent Queues.
Method -log: which is replacement for deprecated dispacth_debug.
Better macro for dispatch_once.