By Katie Marsal and Kasper Jade

Published: 04:00 PM EST

For the second time in as many years, Apple Computer is looking to outshine rival Micrsoft Corp. in the inevitable battle between the two companies' software operating systems.

There's still over a month to go before Apple will take the wraps off Leopard, the next version of Mac OS X, but already the rumor mills are abuzz over a couple of purported screenshots that depict some long-rumored features of the software.

Leopard is due to hit the market about the same time as Microsoft's Vista, and sources say Apple has been keeping a close eye on the Redmond, Wash.-based software giant. They say the Mac maker has been developing a handful of features for Leopard that will specifically rival those available to Vista users -- some will make the cut for Leopard's release while others may not.

One of the rumored features is said to be OS-level integration of a geographical mapping technology, similar to Microsoft's Virtual Earth. In recent months, Microsoft has made several acquisitions aimed at bolstering its Virtual Earth division, including a buyout of Vexcel Corp.

According to sources, Apple has been working on a similar approach, but modeled after Google's Maps feature. The technology will presumably allow Leopard users to scour the globe through satellite imagery and whisk up driving directions on the drop of a dime.

Another rumored feature of Leopard -- one which appears to be shown in the unauthenticated Leopard screenshots -- is the unification of Apple's Address Book and iCal applications into a single app. Interestingly, the two screenshots making the rounds on the Web this week indeed show a revised Address Book icon that also displays a date. This is coupled with the absence of the traditional iCal icon in the Mac OS X Dock.

Still, the juiciest rumors surround Apple's Boot Camp and where the company may or may not take the technology. Although sources did not explicitly say that Boot Camp would be transformed into a complete virtualization solution, they did say the technology is being groomed as a rival to Microsoft's Virtual PC Express.

In March, Microsoft released an "Early Release" of Virtual PC Express, saying it would allow users "to run an operating system as a host (such as Windows XP Professional) and run another operating system as a guest in the virtual machine (such as Windows 2000)."

"This Early Release does not support Windows Vista since Windows Vista has not yet been released," Microsoft said. "When Windows Vista Enterprise ships in late 2006, it will include Virtual PC Express, which will support Windows Vista as a host operating system (as well as additional enhancements such as support for 64-bit)."

Feature specifics aside, there have been some other rumblings about Leopard. In very much the same way Microsoft decided to market its next-generation OS under the name Vista (rather than its code-name "Longhorn"), Apple is also rumored to be mulling a "more marketable" name for its next-generation OS. However, it's unclear if Apple will ultimately go through with the change.

Apple plans to unveil Leopard for the first time at its World Wide Developers Conference, which runs from Aug. 7 - 11 at the Moscone Center in San Francisco, Calif.