Please note: this article is part of the older "Objective-C era" on Cocoa with Love. I don't keep these articles up-to-date; please be wary of broken code or potentially out-of-date information. Read "A new era for Cocoa with Love" for more. It is very easy, when developing on a new operating system, to create projects that won't run on any previous OS version. To ensure backwards compatibility, t

