Objective-C is an ANSI C compatible language with dynamic object-oriented extensions. It combines the power of Smalltalk-style message passing with the performance and native system-level access of C. From the start, the abilities of Obj-C have fueled the power of the Cocoa framework. Now in Leopard, the Objective-C runtime has been updated to include a thoroughly modern and high performance garbage collection system, making memory management a thing of the past.
Also new in Objective-C 2.0 are a set of syntax improvements, including property accessors and fast enumeration. These improvements bring the language up-to-date with the expectations of today’s programmers. And, since Objective-C 2.0 is compatible with existing Objective-C source, you can adopt it at your own pace.