Ladies and gentlemen, we are witnessing the most anticipated match in the history of smartphones for the heavyweight championship of the world. Are you ready? For those watching around the world, let's get ready to rumble!

For this battle, we're comparing the four heavyweights: Android, BlackBerry, iOS, and Windows Phone 7. Symbian is on the fast track to extinction, and WebOS (found on Palm and some HP devices) is a minor player.

Gladiators, Step Forth

Android:

They say it takes a village to raise a child, and Android is a great example. It's parented not only by Google but also by the members of the Open Handset Alliance, many of whom are among the biggest, baddest companies in the world. It's no wonder that this puppy is tearing through everyone else's market share. Android first appeared on a phone in October 2008.

BlackBerry:
The veteran of the four, the BlackBerry OS hails from Research in Motion. When they debuted in 1999, BlackBerry devices were little e-mail machines, and that was pretty much it. Now running on OS version 6, with 7 on the horizon, they can do a lot more.

iOS:
The first iPhone was born in June 2007 to Apple. What was then known as "iPhone OS" in 2010 changed its name to iOS to incorporate the iPad, iPod Touch, and Apple TV. Coveted by yuppies, hipsters, and pretty much everyone else, iOS looks tough to beat.

Full of widgets, apps, and shortcuts, this is an example of extreme customization on Android.
 
Windows Phone 7 (WP7):

The rookie. The successor to Windows Mobile OS (and Symbian's usurper), Windows Phone 7 is Microsoft's newborn, first appearing in November 2010. Windows Phone 7 was a major shift in focus from the business world to the consumer world, and Microsoft temporarily dropped support for many business features to get this first iteration out. Adoption has been slow, but now that Microsoft has partnered with Nokia, some analysts are predicting a growth spurt. As one might expect from the youngest OS, many features are still missing, but a number of those omissions should be addressed in this fall's "Mango" update.
Now, contenders, return to your corners and come out swinging!

The Battles

Apps:

Apple's App Store has the most apps available for a phone (nearly 380,000), but soon it will be overtaken by the Android Market (about 300,000), perhaps this summer. Android has already overtaken iOS in the number of free apps. BlackBerry App World hovers somewhere around 30,000 apps, but it is expected that before turning a year old, the Windows Phone 7 Marketplace (currently about 18,000 apps) will surpass it later this year.

The quality of the apps is the subject of much debate, but such a huge number of app developers are publishing across multiple platforms that the argument is becoming somewhat irrelevant. In general, iOS often gets its edition of most apps first, and the apps tend to be more polished when they first launch. Android equivalents catch up quickly, and sometimes even offer more functionality (such as better sharing options and deeper access to the phone's resources).

Windows Phone 7 apps work best when they try to match the aesthetics and flow of that interface, but otherwise tend to fall on their faces. Windows Phone 7 is still young, though, and many of these kinks should be worked out over time. Third-party apps can't multitask at this point, and they don't feel deeply integrated; however, such shortcomings will be fixed with Mango.

Against the other mobile OSs, BlackBerry apps generally feel like 8-bit Nintendo games next to a Playstation or Xbox. Both quality and selection are sorely lacking, and the even best BlackBerry apps are generally less user-friendly than their counterparts on other platforms.

Apps Winner: iOS gets the win here, with Android close behind.

Productivity and Business Apps:

Windows Phone 7’s Office Hub, a beast of a productivity suite.The vast majority of U.S. businesses work in Outlook, Word, Excel, and PowerPoint, as well as with Microsoft Exchange (a server for e-mail, calendar, contacts, and tasks). Microsoft Office Mobile on Windows Phone 7 has all that and more. Office files are easy to work with, and can be synced using SharePoint.

Some businesses have made the leap from Microsoft products to those made by Google--such as Apps for Business, Docs, Calendar, and Gmail--and it's a safe bet that more will soon make the jump, with cheap Chromebooks on the way.No other mobile OS integrates as fully with Google products as Android does--it's the only platform with a native Google Docs app. Its Exchange integration is also good. For working with Microsoft documents, third-party Android apps are available.

Apple's excellent iOS productivity suite, iWork, is now available for the iPhone. The App Store is also packed with third-party productivity apps, which range from fantastic to terrible. Exchange integration in iOS is decent. Android and iOS 4, by the way, both allow their devices to be used as Wi-Fi hotspots, which can be a life-saver.

BlackBerry is also relegated to third-party apps for dealing with Office files--including Documents to Go. Blackberry App World is relatively miniscule, though there are gems, such as RIM's BlackBerry Mobile Conferencing. That said, BlackBerry's Exchange integration is second to none--if your business is running BlackBerry Exchange Server (BES). BlackBerry Internet Service (BIS)--the server that's more for consumers--will sync e-mail but not contacts, calendars, tasks, or notes. The other OSs do this without making you pay (BES is about $15 a month more than BIS).

Productivity and Business Apps Winner: Windows Phone 7 wins, thanks to Microsoft Office Mobile.

E-mail:

A condensed view of iOS’s calendar in List mode.BlackBerry e-mail is fast and reliable; plus, it can funnel all of your accounts--and your SMS and BlackBerry Messenger messages--within a single inbox. E-mail on the other three operating systems looks cleaner, but I'll take functionality first.

Android and iOS offer integrated inboxes that combine multiple accounts, whereas Windows Phone 7 keeps them separate (again, this will change with Mango). Interestingly, on Android your Gmail account gets its own app rather than being integrated into the single mailbox.

E-mail Winner: E-mail on any OS works well with Exchange, but BlackBerry wins.

Calendar:

Windows Phone 7 has the best-looking calendar tool of any mobile OS, and it can sync with multiple (non-Google) calendars. (It can sync only with your main Google calendar--one of this OS's limitations.)
Android and iOS have straightforward, easy-to-read calendars. They aren't as pretty as Windows Phone 7's, but they can handle virtually all of the same tasks, as well as multiple Google calendars. Naturally, Android handles Google Calendar better than the rest, but iOS is almost as good (though you may have to go through a few extra steps to use multiple calendars).

BlackBerry's calendar does most of what the others do, but it doesn't look as good. It has trouble with multiple Google calendars, and if you want it to sync with Exchange you need BES, as BIS can sync only e-mail. This should change to serve the consumer market.

Calendar Winner: Windows Phone 7 edges out Android and iOS.

Contacts:

Windows Phone 7’s gorgeous calendar is way easier on the eyes than the rest.All four operating systems deal with contacts fairly well, supporting multiple Exchange accounts and allowing you to integrate contacts from different Exchange accounts. But again, with BlackBerry, you can wirelessly sync contacts only if you're on a BES server or use third-party software.

Contacts Winner:
Android gets the nod for merging contacts wirelessly from multiple e-mail accounts and Exchange accounts, as well as Facebook and Twitter. If you already rely on Gmail, though, Android is a clear winner.

Remote Control and VNC Options:

VNC stands for Virtual Network Computing. It means, essentially, the capability to control a computer remotely, via the Internet, from another computer or mobile device. It's handy in a pinch, less so on devices with smaller screens and slower processsors. Android and iOS have the most and the best VNC options, with LogMeIn Ignition at the forefront. For Windows Phone 7, Remote Desktop is the most popular.

BlackBerry falls behind; the few VNC clients built for it have low user ratings. The most popular is VNC Plus, but don't expect too much if you're using devices with smaller screens and slower processors.

Remote Control and VNC Winner: Android and iOS tie.

Keyboards:

iOS had the first great touchscreen keyboard. It's generally responsive and accurate, and text correction works well. The first time I saw the software keyboard on Windows Phone 7, I thought there was no way I could type on its tiny "buttons." Yet somehow, my typing was quick and accurate. Its text prediction and autocorrect are good, but better key visibility would be nice.

One big reason to buy a BlackBerry phone is for its hardware keyboard. Touchscreen keyboards on BlackBerrys, however, are nothing to write home about.

The native keyboard standard in Android is decent, but the option to install third-party keyboards is great. Options include the sliding keyboards Swype or SlideIT, and the almost spooky text-prediction of SwiftKey.
SwiftKey is one of the slick replacement keyboards available for Android.

Keyboards Winner: Android rules this hard-fought category.

Security:

From a business standpoint, BlackBerry remains the gold standard in security. All of the operating systems have remote-wipe capabilities, can set unlock passwords, and can help you find a lost device, but BlackBerry has more end-to-end data encryption than the others--including encryption for removable storage.
Windows Phone 7 lags a bit, though more security features will come with Mango. It's worth noting that third-party iOS and Android apps often share more information than you would like, so read the permissions before you install. (For a more in-depth analysis, check out this PCWorld Business Center article on smartphone security.)

Security Winner: The BlackBerry OS locks it down.

Source : pcworld