User Assistance. This is helping the user with the proper "next step" when performing a task. Less guesswork for the user on what to do next makes for a better experience.

You Must Promise. To call your mother, to help old ladies cross the road, and to turn your cell phone off at the movies.

Okay, I just told you what Apple wants you to look out for with window positions, but in the real world, not everyone uses the hiding feature of the Dock, and it is unrealistic to be able to predict where each user will place their Dock at any given day or how large they will have it. However, you can build a feature into your application that allows spacing for the Finder. You can give users the option of where to position their windows and what area of the screen not to cross. I know that BBEdit provides me with this feature, and I wish more developers gave me more control over my windows.

For my Paint application, I created a series of icons to simulate a rendering algorithm. While the application is performing this CPU-intensive task, you can always see the status of the document by the icon changing in the Dock.

If an application is designed well, the reward for users is that they will learn it faster, accomplish their daily tasks more easily, and have fewer questions for the help desk. As a developer of a well-designed application, your returns on that investment are more upgrade revenue, reduced tech support, better reviews, less documentation, and higher customer satisfaction. The rewards of building a good-looking Aqua application are worth taking the extra time.

Drawers. Similar to Sheets, this is a "child" window that gives users access to items that do not always need to be present. But when do you use a drawer and when do you use a palette?

Adhere to Window Models. Document windows, Utility windows, Click-through, Layering, Drawers, Controls. How do users open windows, how do you properly title windows?

To help you become a good Aqua citizen, Apple has created a few guidelines. I've put together a brief overview of them, and we'll be tackling many of them in the months to come.

Not quite as entertaining as Shrek, but Dock animation can be an important and useful function in your application. For example, Dock animation is a helpful way to indicate the status of your application.

Adhere to System Appearance. Does your application use all the sweetly colored buttons, delightfully shaded windows, and all the other "bells and whistles?"