Cocoa is an object-oriented development environment available in Apple's Mac OS X environment. Mac OS X, a unified operating system and graphical operating environment, is the fastest growing Unix variant on the market today. Hard-core Unix programmers, developers who cut their teeth on classic Mac operating systems, and developers who cherished NeXTSTEP, the decade-old system on which today's Cocoa is based -- all are flocking to Cocoa, and they...