Microsoft Build 2014: Nadella adopts "challenger mindset" with free Win 8 for small tablets and mouse-friendly OS updates

And Nokia joins the party with three new device announcements

Microsoft has announced that it will offer the Windows 8 platform free for all devices with screens that measure under nine inches, or for machines connected to the Internet of Things. A Windows 8.1 update will also add more usability features for keyboard and mouse users.

The announcements came during the company's Build 2014 developers' conference today, in which new CEO Satya Nadella said Microsoft is planning to "innovate with a challenger mindset".

"We're not an incumbent - you'll see us make progress at a massive pace," promised Nadella.

These statements followed the revelation that Windows 8 will now be free for all devices with screens under nine inches in size, as well as for devices which feature machine-to-machine communication through the Internet of Things - an area Microsoft is seemingly itching to pursue.

Nadella reminded the audience that Windows APIs are now 90 per cent identical across all Windows-running devices - including the Xbox One games console, which Microsoft also announced will now play host to Windows Store apps under the new "Windows universal apps" system, which bridges development across platforms.

In order to keep Windows 8.1 - the current version of the operating system - ticking over for this ubiquity, Microsoft also announced a Windows 8.1 update that will add a host of keyboard and mouse functionality to the platform - answering criticisms from many CIOs and IT managers.

Further to this, the desktop taskbar will now display running Modern applications, which will sit alongside Win32 programs across the bottom of the screen. This should remove the need to keep toggling between the two interfaces - a universally unpopular feature.

The Modern interface will now allow right-click functions, letting users group and drag numbers of app tiles. Tiles for power and settings will also now be pinnable to the Modern interface.

The Start Menu - which Microsoft only (and arguably only partially) restored to Windows 8 in the 8.1 update - was also shown displaying apps from the Modern interface - good news for developers who crave ‘discoverability' for their applications in a desktop setting. This particular addition will appear in a later update, however, and not in the Windows 8.1 update, which is coming to devices from 8 April 2014.

Nokia CEO Stephen Elop was also on hand to reveal three new Nokia devices, starting with the Lumia 930.

Packing a 2.2GHz quad-core Qualcomm Snapdragon 800, the device is already available in the US as the Nokia Lumia Icon, but a quick respray and iPhone-like metallic surround have made it what Elop called a "flagship" device - presumably after Windows Phone 8.1 works its magic.

Computing had a little hands-on with the device and its new software, particularly enjoying 8.1's ability to display three vertical columns of apps, plus a persistent background image that developer options can allow to display through transparent app tiles.

The lower-specced Lumia 630 and similar, but dual-sim equipped, Lumia 635 were also unveiled. They will be on sale from May, with the Lumia 930 appearing from June.