Microsoft has allowed app developers to upgrade their retail Windows Phones to the new Mango version of the operating system, ahead of a wider release to the public.
The Mango upgrade was announced on Tuesday on the MSDN App Hub page, where registered developers in 23 countries, including the UK, were told they could have the beta version of Mango.
Those wishing to develop apps for the Mango build 7661 will first have to update their software development kit (SDK) to Windows Phone SDK 7.1 Beta 2.
Mango allows contacts to be grouped, making targeted group messaging possible, and also groups email threads. Other new features include a visual search tool called Bing Vision, an enhanced voice-to-text app and the ability to easily switch between multitasking apps.
Crucially for developers, Mango brings up app suggestions when the user searches for something in Bing, but only if the developer has enabled the App Connect feature.
The upgrade to the Windows Phone platform will be installed on new handsets from this autumn, but there is no word yet on when the upgrade will be made available to existing customers.