When talking about Apple everyone mentions the hardware products they make. While the iPod, iPhone and Macs are clearly the products that sets Apple apart, it is important to remember that the real secret behind the success of Apple's hardware is the software that powers it, OS X.

Apple now uses OS X in all of its products except for the iPod Shuffle and is constantly updating and improving it. The next major release of OS X, Leopard is due to be released at the end of the month and this prospect excites analysts as much as users.
Like all previous versions of OS X before it, Leopard is being released at the end of the last month of the financial quarter. While Leopard may not be a revolution in itself, many are waiting to get their hands on the many improvements it brings, and this is going to bring a lot of money for the company.

Tiger had an installed base of 12 million users to grow on, but, due to the constant growth in Mac sales, Leopard is looking at 23 million users. Analysts are using these figures to predict that Leopard will add $240 million to Apple's Q4 2007, almost double the $125 million Tiger made in its launch quarter.
Add to this the number of users that will upgrade their machines along with the operating system and Apple is looking at a significant revenue stream in the quarter ahead, which could be even bigger if the company does indeed come out with new Mac models.

Apple's other software suites, iLife and iWork, are also doing very well, as is Aperture and the other pro applications that Apple makes. While the touch interfaces in the iPhone and iPod touch may be what catches the eye, the real secret behind them is OS X, and while it may not be seen as such, Apple continues to be a very strong software company.