Microsoft Windows 10 Mobile
Microsoft's Joe Belfiore demonstrates Windows 10 which has been given a launch date of this summer Microsoft

Ahead of its Build developer conference in April 2015, Microsoft has launched a preview of the Windows 10 software developer kit (SDK) to allow developers create apps.

While the launch is a surprise, Microsoft is obviously keen to get developers on board as early as possible as it seeks to create a platform for them to write their app once and publish it on multiple devices.

Windows 10 will launch in the second half of 2015 and will run on devices as diverse as desktop PCs, laptops, tablets, smartphones, the Xbox games console, servers and even Internet of Things (IoT) devices.

Microsoft's Cliff Simpkins, announcing the release, warned that this was only a glimpse of what the final developer tools will look like:

"I'd like to point out that this is a preview. Our goal with this release is to give you the opportunity to experiment with the cool new platform capabilities while we continue working to finish Windows 10."

Optimising apps

The initial SDK preview will give developers an idea of how to tweak their apps to work across multiple screen sizes as well as optimising them for both touchscreen and mouse/keyboard inputs. Previously dubbed Universal Apps by Microsoft, the company now calls them simply Windows Apps, which it says will work across all devices.

The preview will also hopefully give an insight into just how easy it will be for iOS and Android developers to port their software to Microsoft's new platform, a key aspect of the new operating system as the company looks to offer smartphone and tablet owners a viable third alternative.

Microsoft had been expected to launch its developer preview at its annual Build developer conference which kicks off on 29 April but having announced a sooner-than-expected release date (summer rather than autumn in the northern hemisphere) it seems Microsoft is keen to get things moving on its new software.

The company is currently testing the desktop version of Windows 10 through its Technical Preview which offers enthusiasts and early adopters a glimpse of what the new software will be able to do.

Windows 10 is a major overhaul of the company's Windows 8 operating system which is widely seen as a misstep by the company. As well as getting a visual overhaul with a new Start Menu and specific tablet and desktop modes, Microsoft is also introducing the brand new Spartan browser to replace Internet Explorer and will incorporate its personal digital assistant Cortana deeply into the OS.

Download Windows 10 SDK preview

If you are a developer and want to build apps for Windows 10, then here are Microsoft's instructions on getting started:

To get started with the preview:

  1. If you haven't already, Join the Windows Insider Program. Instructions and downloads links are now available to get your developer machine set up.
  2. Once installed, get started by creating a Windows app using the universal app templates. You can find them under the | Windows 10 node – see the screenshot below.
  3. If you run into any issues while you are experimenting with this preview...
    1. First, check out the release notes and known issues with Visual Studio 2015 CTP6 to see if it's a known issue.
    2. Continue to use the Windows and Windows Phone apps MSDN forum for development issues.
    3. If you believe you found a bug, you can use the new Developer Platform categories in the Windows Feedback app that is installed as part of Windows 10.
  4. If you have a platform capability or API suggestion, please continue to post them to the Windows platform developer UserVoice site. Please note that we will be updating this site between now and Build to reflect the new capabilities of Windows 10.