Windows 10 (codenamed Threshold) for mobile devices is a mobile operating system, developed by Microsoft, succeeding Windows Phone 8.1. It will primarily aim to bring tighter integration and unification with its PC counterpart Windows 10, and provide a platform for both smartphones, and small tablets under 8 inches in screen size. Windows 10 (mobile) supports ARM as well as Intel x86 system-on-chips.
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Windows 10 Mobile on a flagship Lumia
Windows 10 Mobile on a flagship Lumia

Windows Phone 8.1 smartphones will be eligible for upgrade to Windows 10, pursuant of manufacturer and carrier support. Some features may vary depending on hardware compatibility.

The first Technical Preview for Windows 10 Mobile was made available for download to select Lumia smartphones as of February 12, 2015.

Development
Microsoft had already begun the process of unifying the Windows platform across device classes in 2012; Windows Phone 8 dropped the Windows CE-based architecture of its predecessor, Windows Phone 7, for a platform built upon the NT kernel that shared much of the same architecture with its PC counterpart Windows 8 including file system (NTFS), networking stack, security elements, graphics engine (DirectX), device driver framework and hardware abstraction layer. At Build 2014, which was held a few months prior to Nadella’s announcement, Microsoft also unveiled the concept of a “universal Windows app”. With the addition of Windows Runtime support to these platforms, apps could now be ported to Windows Phone 8.1 and Xbox One while sharing a common codebase with their PC counterparts. User data and licenses for an app could also be shared between multiple platforms.

Screenshot of Windows 10 Mobile on smartphones
Screenshot of Windows 10 Mobile on smartphones

In July 2014, Microsoft’s then-new CEO Satya Nadella explained that the company was planning to “streamline the next version of Windows from three operating systems into one single converged operating system for screens of all sizes,” unifying Windows, Windows Phone, and Windows Embedded around a common architecture and a unified application ecosystem. However, Nadella stated that these internal changes would not have any effect on how the operating systems are marketed and sold.

On September 30, 2014, Microsoft unveiled Windows 10; Terry Myerson explained that Windows 10 would be Microsoft’s “most comprehensive platform ever,” promoting plans to provide a “unified” platform for desktop computers, laptops, tablets, smartphones, and all-in-one devices. Windows 10 on phones was publicly unveiled during the Windows 10: The Next Chapter press event on January 21, 2015; unlike previous Windows Phone versions, Windows 10 will also expand the platform’s focus to small, ARM-based tablets, thus making it a de facto successor to Microsoft’s commercially unsuccessful Windows RT platform (which was based upon the PC version of Windows 8). Windows RT devices will receive a different update with some of the features of Windows 10 for PC.

Naming
In accordance with Microsoft’s unification strategy, this version of Windows Phone will be branded primarily as “Windows 10” without any disambiguation, rather than “Windows Phone 10”, although it was also referred to as “Windows 10 for phones and small tablets” during the event, and leaked screenshots from a Technical Preview build identified the operating system as “Windows 10 Mobile”. Microsoft had begun to phase out specific references to the Windows Phone brand in its advertising in mid-2014. However, critics have still considered the operating system to be an iteration and continuation of Windows Phone due to its lineage and similar overall functionality.The technical preview is officially called the “Windows 10 Technical Preview for phones”.

Windows 10 Continuum Start menu
Windows 10 Continuum Start menu

Release
Windows Phone 8.1 smartphones can be upgraded to Windows 10 for mobile, pursuant to hardware compatibility and manufacturer support. Not all phones will receive the update or support all of its features.

In November 2014, a post by a Microsoft Twitter account stated that all Nokia and Microsoft Lumia smartphones running Windows Phone 8 and 8.1 would receive updates to 10, but following the official unveiling, Microsoft reiterated and stated that they were targeting the “majority” of Lumia phones. In February 2015, Joe Belfiore stated that Microsoft was “working on” a version of 10 for low-end devices with 512 MB of RAM, specifically citing the Nokia Lumia 520—a model which represents 23.8% of all Windows Phone devices sold, but reaffirmed that not all of its features would be supported on these devices.

The “Windows Insider” program, adopted to provide a public beta version for the PC version of Windows 10, is used to provide a public beta version of Windows 10 for selected mobile devices.

Windows 10 Hololens Virtual Reality
Windows 10 Hololens Virtual Reality

Features
A major aspect of the operating system is a focus on harmonizing user experiences and functionality between different classes of devices; particularly, devices running the PC-oriented version of Windows 10, and smartphones. Under the “universal app” concept, Windows Runtime apps for Windows 10 on PC can be ported to other Windows platforms, such as Windows 10 on mobile, and share nearly the same codebase, but with adaptations for the specific device class. Windows 10 on mobile will also, where applicable, share user interface elements with its PC counterpart, such as an updated Action Center and settings menu. During its initial unveiling, Microsoft presented several examples of universal apps that would have similar functionality and user interfaces between Windows 10 on desktops and mobile devices, including updated Photos and Maps apps, and new Microsoft Office apps.

Notifications can be synced between devices; dismissing a notification on, for example, a laptop, will also dismiss it from a phone. Certain types of notifications now allow inline replies. The start screen now has the option to display wallpapers as a background of the screen behind translucent tiles, rather than within the tiles. The messaging app adds support for internet-based Skype messaging alongside SMS, similarly to iMessage, and can synchronize these conversations with other devices. The camera app has been updated to match the “Lumia Camera” app previously exclusive to Lumia products, and a new Photos app aggregates content from local storage and OneDrive, and will be able to perform automatic enhancements to photos. The on-screen keyboard now contains a virtual pointing stick for manipulating the text editing cursor, a dedicated voice input button, and can be shifted towards the left or right of the screen to improve one-handed usability on larger devices.

A new iteration of the Office Mobile suite, Office for Windows 10, will also be included with the operating system. Based upon the Android and iOS versions of Office Mobile, they introduce a new user interface with a variation of the ribbon toolbar used by the desktop version, and a new mobile version of Outlook. Outlook utilizes the same rendering engine as the Windows desktop version of Microsoft Word. The “Spartan” web browser will replace Internet Explorer Mobile.

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Source: Wikipedia
Photos: Windows10Insider.com