When it comes to Apple's new operating system, Leopard, users are likely to notice the flashy graphics and animations, the tight integration of applications and the speed with which it churns through data. What they don't see are a large number of the under-the-hood changes that Apple built in so that its own developers -- and those who come up with third-party apps -- use all of that underlying software goodness.

Apple has always taken advantage of the fact that its own internal developers write both the operating system and the applications that catch the public's eye. Think Safari. The iLife suite. Time Machine. Each new version of the operating system -- as well as those all-important programs -- can thus offer not only new features, but seamless integration and more visual flair.

In a software ecosystem whose target audience has extremely high expectations -- from Apple CEO Steve Jobs all the way down to the newest Mac owner on the block -- visual flair and application integration with the operating system can literally make or break a developer's application.

But the result, especially when the developer tools needed to code all those programs are updated, can be astonishing.

For example, when Time Machine was first demoed at last year's Worldwide Developers Conference, the audience was understandably wowed. As the much-ballyhooed backup app launched and the desktop dropped off the screen to reveal a deep-space backdrop and countless Finder windows retreating into the cosmos, it was clear Apple had done its work with the visuals.

But Time Machine's integration with the operating system and other Apple applications was even more impressive, linked as it is to the file system and the Finder, indexed with Spotlight and joined seamlessly with Apple's legendary ease of use.

With that kind of competition, how can a small developer keep up? For those developing for Leopard, the real questions are: Can we do that, too? And if so, can we do it easily?

The answer is yes. Even developers with limited resources can take advantage of Leopard's new developer tools -- included as an optional install on the operating system's disk -- allowing them to build applications as powerful and flashy as anything coming out of Cupertino.

Leopard offers a generous number of new and improved frameworks, solid system-level foundations, new application technologies and even simpler developer tools than those that accompanied Tiger when it came out in 2005.