Microsoft Monday unveiled Windows Phone 8, the software giant's next-generation mobile software, which it hopes will propel it to the top of the ultra-competitive smartphone market.

The launch of Windows Phone 8 comes just four days after Microsoft lifted the curtain on Windows 8, its latest software for tablets, desktop, and notebook PCs. Both software releases are based on the same core technologies, meaning they share the same networking, security, and web browsing features, and afford developers and users a one-size-fits all experience across both Windows 8- and Windows Phone 8-based devices.

"If you are one of the hundreds of millions of people who will use Windows 8 in the next year, there is no better phone for you than a Windows Phone," Microsoft CEO Steve Ballmer said Monday during the Windows Phone 8 launch event in San Francisco, which was streamed live on the Microsoft Web site. "As you have seen already, all Windows 8 devices, from desktops to notebooks to laptops to tablets and phones, share the same iconic look and feel. The same live tiles will update as the world around you changes."

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Ballmer explained that users will be able to access the same photos, music and other files across all devices running these new Windows operating systems, leading to a seamless and consistent experience for both consumers and enterprise users.

What's more, Ballmer stressed that Windows Phone 8 stands apart from other competing smartphones by delivering a completely customizable UI. By "pinning" the people and applications they connect with most often, users can adjust the interfaces of their Windows Phone 8 devices to ensure the information most relevant to them is always easily accessible.

"It is the most personal smartphone available," Ballmer said at the event. "We reinvented Windows Phone around you." Joe Belfiore, Microsoft's corporate vice president of Windows Phone, stressed that this customizable interface affords users a break from the "tired old metaphor" that has become iOS and Android devices.

Still, Microsoft faces a major uphill battle in its ploy to make Windows Phone 8 a serious contender in the smartphone market. According to Gartner, Microsoft's Windows Phone OS accounted for a meager 2.7 percent of the worldwide smartphone market during the second quarter, a figure that pales in comparison to Android's 64.1 percent and iOS' 18.8 percent.

But, according to Nick Dillon, an analyst with U.K.-based analyst firm Ovum, Windows Phone 8 may have what it takes to finally turn things around for Microsoft, namely because of its similarities with Windows 8.

"One of the main reasons Windows Phone has struggled is consumer acceptance: while there is very little wrong with the software, its design is significantly different from the current status quo of the 'grid of apps' user interface, and this change represents a perceived risk to potential customers," Dillon wrote in a research note Monday. "However, in the last year Microsoft has built consumer familiarity with the new design by extending it to both its Xbox console and its PC and tablet operating system, Windows 8."

NEXT: Windows Phone 8 Features, Hardware

Microsoft is hoping to fight back against its rivals by first expanding its Windows Phone ecosystem of apps; according to Belfiore, there are now more than 120,000 apps available for Microsoft's OS, a number that is growing by the "hundreds" every day.

What's more, Microsoft is hoping to lure consumers with new Windows Phone-specific features, such as Data Sense, a tool that tracks data usage and warns users when they are close to exceeding their monthly data caps. Belfiore said the new tool also allows Windows Phone 8 devices to compress web pages to keep data usage at a minimum, while also alerting users of nearby WiFi hot spots they can use to conserve cellular data. All in all, Belfiore said the new Data Sense feature allows Windows Phone 8 devices to use 45 percent less data than competing smartphones.

Another new feature exclusive to Windows Phone 8 is Kid's Corner, a separate mode users can select and populate with curated content for children.

A number of smartphone makers including Samsung, HTC and Nokia have already unveiled phones running the new Windows Phone 8 OS. For Nokia, the stakes are especially high; the Finnish handset maker has been struggling to keep up with rivals Apple and Google after pledging its allegiance to Microsoft's mobile OS in February 2011.

Nokia has based its upcoming Lumia 920 smartphone on Windows Phone 8, while its existing Lumia devices will be upgraded to a water-downed version of the new OS, called Windows Phone 7.8. Smartphones running prior-generation Windows Phone releases are not upgradeable to Windows Phone 8 because they lack certain hardware requirements, such as support for higher-resolution displays, multi-core processors, and near-field communication, Microsoft has said.

Microsoft's Ballmer said smartphones running Windows Phone 8 will start launching this weekend in Europe, and will U.S. availability slated for next month.

PUBLISHED OCT. 29, 2012