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.

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.

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

In building your amazing Aqua application, one of the most important things to consider is the Dock. There are three things your app needs to be "Dock Compliant." Now, I write this knowing that the Dock will be going through some major changes soon, but for the most part, these should still hold true.

So far in these articles, I have only dipped a toe or two into Aqua's pool. I have covered basic aspects of building an Aqua-compliant application, including the building of photo-illustrative/3D application icons. Now it's time to address other components of our Mac OS X application.

This is the first thing your users see, and probably the single most important visible part of your application. It is the first chance you have at making an impression and the best chance to help establish your brand.

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

In building your amazing Aqua application, one of the most important things to consider is the Dock. There are three things your app needs to be "Dock Compliant." Now, I write this knowing that the Dock will be going through some major changes soon, but for the most part, these should still hold true.

Adopt Sheets. I really like the use of Sheets in OS X. The use of Sheets lets me know which window my dialogue belongs to without hijacking my system.

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.