Marcus Zarra is the owner of Zarra Studios, LLC and the creator of seSales and iWeb Buddy. In addition, he is a coauthor of Cocoa Is My Girlfriend, a wildly popular blog covering all aspects of Cocoa development. Zarra has been developing software since the mid-1980s and has written software in all the major technological fields.
Matt Long has been in the software industry since 1996. He has developed software with a wide array of technologies and platforms in addition to OS X and the iPhone, including Unix, Microsoft Windows, and Microsoft .NET. His experience on these other platforms makes him uniquely qualified to help other programmers who are themselves making the transition to the Mac OS X and iPhone using Cocoa and Cocoa Touch. In addition, he writes for the Cocoa Is My Girlfriend blog, which demonstrates usage of not only Core Animation but many other technologies related to Mac OS X and the iPhone.