Microsoft released its Windows Phone "Mango" operating system to device manufacturers and carriers July 26. It will enable application multitasking for background processing, audio and file transfer, and fast program switching, among other new features. (For extensive details on the upgrades included in Mango and the revised developer tools, see our previous coverage.)

Two new Mango-equipped phones are now expected for September or October release: Nokia's "Sea Ray" and the Toshiba-Fujitsu IS12T, and carriers are expected to begin trickling the upgrade out to existing handset owners at around the same time.

In turn, Microsoft has said its online Marketplace for Windows Phone 7 apps will be open to Mango-specific submissions from developers starting Aug. 22. (And, an Aug. 16 Windows Phone blog posting listed 14 Xbox Live titles that will be coming to Windows Phone "in the months ahead.")

"Bug Village" is an Xbox Live game that will come to Windows Phone, according to Microsoft

To prime the pump for developers, the software giant released a Windows Phone Developer Tools 7.1 beta on May 24, following it up with an updated (and renamed) Windows Phone SDK 7.1 Beta 2 on June 29. The tools will be revised again to RC (Release Candidate) status later this month, Microsoft promised July 20.

New Silverlight toolkit

Amidst all this activity, Microsoft also fielded a new toolkit for developers using Silverlight to create their Mango apps. Announced Aug. 17, the Silverlight for Windows Phone Toolkit (August 2011) add-on provides "user interface controls like those found throughout the Windows Phone, with components like toggle switches, page transitions, picker controls and more."

New components in the Silverlight for Windows Phone Toolkit are said to include the following:

• Smooth new LongListSelector designed for Windows Phone 7.1 OS
• MultiselectList
• LockablePivot
• HubTile
• ExpanderView
• LocalizedResources
• DateTimeConverters
• DateTimePickers
• HeaderedItemsControl
• PhoneTextBox
• Improved Transitions performance
• Improved ContextMenu performance
• ListPicker supports multiselect
• Various bug fixes

The verbiage used in the above list, as well as Microsoft's naming of its developer tools, suggests that Mango will be officially known as Windows Phone 7.1, though we've also heard it called Windows Phone 7.5.

Meantime, a subsequent version -- codenamed "Tango" -- has already surfaced. An Aug. 4 posting on Pretaktovanie.sk pictured what's purported to be a screen (pictured) from Build 8200 and describes new features.

Is this the Tango version of Windows Phone 7?
(Click to enlarge)

According to "Snake," described as a forum moderator, Tango will include a global search feature that first looks for content on the phone itself, and then searches the web. Voice-activated searching will also be possible, the post adds.

There's no confirmation that the genuine-seeming screen is what it purports to be, but a Tango upgrade to Windows Phone was tipped by DigiTimes as early as June 28. That information was said to have come from Compal, an ODM that will apparently be manufacturing handsets for Nokia.

On July 31, Build 8200 versions of Windows Phone 7 were detected in the wild by a tool known as "Dude, where is my update," according to Japanese website Nanopho. Tango could include new features such as Skype integration and added Bluetooth device profiles, the website added.

Nanopho's item, attributed only to "tezawaly," adds that other planned Windows Phone features include an Internet Explorer 10 browser, in-app billing systems, and enterprise device management capabilities. However, the website doesn't say whether they'll be included in Tango or in an "Apollo" version that will be its successor.

Apollo is a code name that was first revealed in a prescient post last December by Microsoft watcher Mary Jo Foley. At the time, she theorized that this nickname refers to Windows Phone 8, which will be released in late 2012.

Jonathan Angel can be reached at jonathan.angel@ziffdavisenterprise.com and followed at www.twitter.com/gadgetsense.

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