Best solution for developers learning Cocoa. Joy provides the best solution for developers to learn Cocoa, the new way of developing applications for MacOS X. It softens the steep learning curve for the Yellow Box frameworks. You can inspect classes and objects in running applications, interactively try out methods on them, and look at the values of instance variables. Joy is without competition when it comes to rapid prototyping. Say 'New Joy Application' in ProjectBuilder and click 'Build' for the first and last time. Then hack away! Joy includes rapid turnaround functionality, meaning you need not rebuild your program after changing a Joy script or a nib file.