Nokia's Lumia lineup first to receive upgrade.
Following the launch of its development kit, Microsoft has, as planned, released the Windows Phone 7.8 update.
Finnish handset manufacturer Nokia is the first to roll out the update to several Lumia smartphones. The Lumia 510, 610, 710, 800 and 900 are all expected to receive the update in due course, but Nokia said availability is dependent on carrier approval.
"The Windows Phone 7.8 update is now rolling out for Nokia Lumia smartphones through February," it said. "Delivery of the update is operator dependent, meaning you will receive a notification in the coming weeks if you have an unlocked phone or if your operator has approved the update."
To upgrade to Windows Phone 7.8 after receiving the prompt to do so, a USB cable is required to connect the device through Zune or the Windows Phone app on Mac, followed by the usual prompts.
Windows Phone 7.8 integrates several features stemming from Windows Phone 8, including the introduction of resizable Live Tiles to a device's home screen. 20 additional color themes and new lock screen wallpapers are also included, while the Zune app has been rebranded as Xbox Music.
Nokia incorporated a few of its own improvements into the updated mobile platform. It added Bluetooth Share, Cinemagraph and Ringtone Maker, in addition to revamping its Contacts Transfer and Contact Share apps.