Windows Phone Series 7 is here, and it's like nothing we've seen from Microsoft—or anyone else—before. But how does it measure up? And where does every other smartphone OS stand?

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iPhone OS 3.x

The third major release of the iPhone's software, and the second since the platform got its App Store, iPhone OS 3.x has succeeded on the strength of simplicity, intuitiveness and a tremendous selection of applications. It serves as the basis for the OS that will ship with the new Apple iPad.

Available: June 2009
Open Source/Free: No
Multiple Handset Manufacturers: No
Multitasking: No
Multitouch Interface: Yes
Browser/Engine: Safari/WebKit
Video Recording: Yes
Upgrades: Sync/Patcher
Syncing Software: Yes
App Store Size: 100k+
App Sideloading: No
Jailbreaking/rooting: Yes
Flash Support: No

Android 2.x

In just over a year, Google's Linux-based Android OS has gone from a rough-edged software experiment to a smartphone powerhouse, running atop some of the most powerful hardware available. Version 2.1 is the software platform for Google's own first phone, the Nexus One. Android phones vary in both hardware configurations and software versions, but are generally increasing in popularity.

Available: October '09
Open Source/Free: Yes/Yes
Multiple Handset Manufacturers: Yes
Multitasking: Yes
Multitouch Interface: Yes
Browser/Engine: Chrome/WebKit
Video Recording: Yes
Upgrades: Over the Air
Syncing Software: No
App Store Size: 20k+
App Sideloading: Yes
Jailbreaking/rooting: Yes
Flash Support: Within six months

Palm webOS 1.x

Palm's webOS represented a complete reboot for the company, whose aging Palm OS found itself outpaced by more modern, finger-friendly offerings from Apple and Google. At the core of the OS is a novel multitasking system, with which users can cycles through apps, or "cards." Another webOS selling point is the deep integration of social networking directly into the OS, and an emphasis on messaging.

Available: June '09
Open Source/Free: No/No
Multiple Handset Manufacturers: No
Multitasking: Yes
Multitouch Interface: Yes
Browser/Engine: webOS/WebKit
Video Recording: Coming soon
Upgrades: Over the Air
Syncing Software: No
App Store Size: 1400+
App Sideloading: No
Jailbreaking/rooting: Yes
Flash Support: Within six months

BlackBerry OS 5

RIM is known for issuing frequent updates for its mobile OSes, but they are minimal, and at heart, BlackBerry OS 5 is deeply similar to its early, decade-old predecessors. BlackBerry OS is inclined towards messaging—its inboxes feature prominently—with web browsing and apps as secondary focuses. RIM's recent success with the consumer (as opposed to enterprise) market shows they've taken pains to improve the usability and aesthetics of the OS, though its corporate roots still show through.

Available: November '09
Open Source/Free: No/No
Multiple Handset Manufacturers: No
Multitasking: Yes
Multitouch Interface: No
Browser/Engine: BlackBerry/Proprietary (WebKit forthcoming)
Video Recording: Yes
Upgrades: Sync/patcher/over the air
Syncing Software: Yes
App Store Size: 3k+
App Sideloading: Yes
Jailbreaking/rooting: No
Flash Support: Within six months

Windows Mobile 6.5.x

Windows Mobile 6.5 is the last predecessor to Windows Phone 7 Series, and it will coexist with WP7 for the foreseeable future, as a bridge for corporate customers. Its basic design and codebase harks back to the early 2000s, and while it featured multitasking, copy and paste and a significant number of 3rd party apps well before the iPhone or Android did, WinMo failed to keep up with its competitors. Even with version 6.5, which added new, finger-friendly interface elements and an app marketplace, success was not to be. Despite its successor's seemingly related name, this is the end of the road for the WinMo OS.

Available: October '09
Open Source/Free: No/Licensed
Multiple Handset Manufacturers: Yes
Multitasking: Yes
Multitouch Interface: No
Browser/Engine: Internet Explorer/Trident
Video Recording: Yes
Upgrades: Sync/Patcher
Syncing Software: Yes
App Store Size: Under 500 1000+, depending on handset
App Sideloading: Yes
Jailbreaking/rooting: No
Flash Support: Yes

Windows Phone 7 Series

Windows Phone 7 Series is a total revamping of Microsoft's mobile strategy, drawing more on design philosophy of the Zune HD than of Windows Mobile. The interface is designed primarily for touch input, and eschews icon grids and menus for a series of paneled hubs. The unreleased OS features deep integration with Xbox and Zune services, as well as a completely new app store.

Available: Holiday '10
Open Source/Free: No/No
Multiple Handset Manufacturers: Yes
Multitasking: No, probably! (With possible exceptions.)
Multitouch Interface: Yes
Browser/Engine: Internet Explorer/Trident
Video Recording: Yes
Upgrades: TBD
Syncing Software: Media
App Store Size: TBD
App Sideloading: TBD (Unlikely)
Jailbreaking/rooting: TBD
Flash Support: TBD (Probable)